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  • 151.
    Santos, Arnoldo
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Lucchetta, Luca
    Monge-Garcia, M Ignacio
    Batista Borges, João
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Tusman, Gerardo
    Hedenstierna, Göran
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk fysiologi.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    The Open Lung Approach Improves Pulmonary Vascular Mechanics in an Experimental Model of Acute Respiratory Distress Syndrome2017Ingår i: Critical Care Medicine, ISSN 0090-3493, E-ISSN 1530-0293, Vol. 45, nr 3, s. e298-e305Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVE: To test whether positive end-expiratory pressure consistent with an open lung approach improves pulmonary vascular mechanics compared with higher or lower positive end-expiratory pressures in experimental acute respiratory distress syndrome.

    DESIGN: Experimental study.

    SETTING: Animal research laboratory.

    SUBJECTS: Ten pigs, 35 ± 5.2 kg.

    INTERVENTIONS: Acute respiratory distress syndrome was induced combining saline lung lavages with injurious mechanical ventilation. The positive end-expiratory pressure level resulting in highest compliance during a decremental positive end-expiratory pressure trial after lung recruitment was determined. Thereafter, three positive end-expiratory pressure levels were applied in a random order: hyperinflation, 6 cm H2O above; open lung approach, 2 cm H2O above; and collapse, 6 cm H2O below the highest compliance level. High fidelity pressure and flow sensors were placed at the main pulmonary artery for measuring pulmonary artery resistance (Z0), effective arterial elastance, compliance, and reflected pressure waves.

    MEASUREMENTS AND MAIN RESULTS: After inducing acute respiratory distress syndrome, Z0 and effective arterial elastance increased (from 218 ± 94 to 444 ± 115 dyn.s.cm and from 0.27 ± 0.14 to 0.62 ± 0.22 mm Hg/mL, respectively; p < 0.001), vascular compliance decreased (from 2.76 ± 0.86 to 1.48 ± 0.32 mL/mm Hg; p = 0.003), and reflected waves arrived earlier (0.23 ± 0.07 vs 0.14 ± 0.05, arbitrary unit; p = 0.002) compared with baseline. Comparing the three positive end-expiratory pressure levels, open lung approach resulted in the lowest: 1) Z0 (297 ± 83 vs 378 ± 79 dyn.s.cm, p = 0.033, and vs 450 ± 119 dyn.s.cm, p = 0.002); 2) effective arterial elastance (0.37 ± 0.08 vs 0.50 ± 0.15 mm Hg/mL, p = 0.04, and vs 0.61 ± 0.12 mm Hg/mL, p < 0.001), and 3) reflection coefficient (0.35 ± 0.17 vs 0.48 ± 0.10, p = 0.024, and vs 0.53 ± 0.19, p = 0.005), comparisons with hyperinflation and collapse, respectively.

    CONCLUSIONS: In this experimental setting, positive end-expiratory pressure consistent with the open lung approach resulted in the best pulmonary vascular mechanics compared with higher or lower positive end-expiratory pressure settings.

  • 152.
    Santos, Arnoldo
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Monge-Garcia, I
    Gomez Peñalver, E
    Borges, João Batista
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Lucchetta, L
    Retamal, Jaime
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Tusman, G
    Hedenstierna, Göran
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    ARDS Decreases Pulmonary Artery Compliance in a Porcine Model2016Ingår i: American Journal of Respiratory and Critical Care Medicine, ISSN 1073-449X, E-ISSN 1535-4970, Vol. 93, artikel-id A7917Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Rationale: Importance of pulmonary hemodynamic disarrangements in ARDS has been remarked recently. In this study we describe the effect of ARDS on pulmonary artery compliance and the related effect on pulmonary hemodynamics. In this way we highlight the importance of pulsatile hemodynamic evaluation beyond the classic evaluation based only on resistance.

    Methods: 17 anesthetized and muscle relaxed pigs were monitored with a transonic flow probe and high fidelity micro-tip pressure sensor placed in the pulmonary artery through a small thoracotomy. An experimental model of ARDS was induced in these animals by means of lung saline lavages followed by two hours of injurious mechanical ventilation. Pulmonary artery compliance was measured as the stroke volume divided by the pulse pressure. Waveform analysis of pulmonary artery pressure and flow signal was applied to calculate the following variables: first harmonic impedance magnitude (inversely related with arterial compliance), characteristic impedance, wave reflections (which are affected by arterial compliance) magnitude and peak and foot arrival time (normalized to cardiac period). These variables are related to the pulmonary vessels efficiency to transmit pressure and flow produced by the right ventricle. In addition, pulmonary vascular resistance was evaluated as usual. Variables were evaluated before (Baseline) and after (ARDS) development of the model.

    Results: Comparing with Baseline, ARDS provoked a decrease in pulmonary artery compliance (3.03±0.99 vs 1.53±0.41 ml/mmHg, p<0.001), and in the wave reflections arrival time of foot (0.18±0.09 vs 0.11±0.05, p<0.001) and peak (0.50±0.12 vs 0.39±0.10, p< 0.001) and an increase in the impedance magnitude of the first harmonic (80±29 vs 145±38 dyn.s.cm-5, p<0.001) and in the pulmonary vascular resistance (230±79 vs 504±129 dyn.s.cm-5, p<0.001). Characteristic impedance and wave reflections magnitude showed no differences.

    Conclusions: In this porcine model, ARDS provoked a decrease in pulmonary artery compliance. This effect was followed by a deterioration of pulmonary vascular efficiency. Our findings can be relevant for the pathophysiology of right ventricle failure during ARDS. This abstract is funded by: European Society of Intensive Care Medicine (ESICM), Basic Science Award 2012, the Swedish Heart and Lung foundation and the Swedish Research Council (K2015-99X-22731-01-4)

  • 153.
    Santos, Arnoldo
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Monge-Garcia, M.
    Hosp SAS, Jerez de la Frontera, Spain..
    Batista Borges, João
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk fysiologi. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Gomez-Penalver, E.
    Hosp Gen Villalba, Villalba, Spain..
    Retamal, J.
    Pontificia Univ Catolica Chile, Santiago, Chile..
    Lucchetta, L.
    Hosp San Matteo, Pavia, Italy..
    Hedenstierna, Göran
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk fysiologi. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk fysiologi. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Pulmonary Vascular Efficiency Worsening And Cardiac Energy Wasting During Early Stages Of Experimental Acute Respiratory Distress Syndrome2017Ingår i: American Journal of Respiratory and Critical Care Medicine, ISSN 1073-449X, E-ISSN 1535-4970, Vol. 195, nr D27, artikel-id A7698Artikel i tidskrift (Övrigt vetenskapligt)
  • 154.
    Santos, Arnoldo
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Monge-Garcia, M. Ignacio
    Borges, Joao Batista
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Gomez-Peñalver, Eva
    Retamal, Jaime
    Lucchetta, Luca
    Tusman, Gerardo
    Hedenstierna, Goran
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk fysiologi.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Acute Respiratory Distress Syndrome deteriorates pulmonary vascular efficiency and increases cardiac energy wasting in a porcine model.Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Background: Right ventricle failure worsen outcomes in acute respiratory distress syndrome (ARDS). However, the pathophysiology of right ventricle failure and vascular dysfunction in ARDS is not completely understood. In this study we aim to evaluate the effects of early ARDS on pulmonary vascular efficiency for transmission of flow and pressure in an experimental animal model.  

    Methods: ARDS was induced in 10 pigs (32.5±4.3 kg) combining saline lung-lavages with injurious mechanical ventilation. Pressure and flow sensors were placed at the main pulmonary artery for pulmonary vascular function evaluation, including arterial load parameters, cardiac power and energy transmission ratio.

    Results: Compared to baseline healthy conditions, ARDS increased pulmonary vascular resistance (199±62 versus 524±154 dyn.s.cm-5, p <0.001), effective arterial elastance (0.65±0.26 versus 1.13±0.36 mmHg/ml, p <0.001) and total hydraulic power (195±60 to 266±87 mW, p =0.015), decreased pulmonary arterial compliance (from 2.34±0.86 to 1.00±0.25 ml/mmHg, p <0.001) and energy transmission ratio (68±15 versus 55±14%, p = 0.014), whereas oscillatory power did not change (17±6 versus 16±6%, p = 0.359).

    Conclusions: In this experimental ARDS model, an increase in pulmonary arterial load was associated with a higher cardiac power and a decrease in the energy transmission ratio. These results suggest that right ventricle energy consumption is increased and part of this energy is wasted in pulmonary circulation worsening pulmonary vascular efficiency in the early course of ARDS. These findings may help to explain primary mechanisms leading to right ventricle dysfunction in ARDS.

  • 155.
    Scaramuzzo, Gaetano
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Univ Ferrara, Dept Morphol Surg & Expt Med, Ferrara, Italy.
    Broche, Ludovic
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. European Synchrotron Radiat Facil, Grenoble, France;Grenoble Alpes Univ, Synchrotron Radiat Biomed STROBE Lab, INSERM UA7, Amiens, France.
    Pellegrini, Mariangela
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Porra, Liisa
    Univ Helsinki, Fac Math & Nat Sci, Dept Phys, Helsinki, Finland;Univ Helsinki, Cent Hosp, Helsinki, Finland.
    Derosa, Savino
    Univ Bari Aldo Moro, Dept Emergency & Organ Transplant, Bari, Italy.
    Tannoia, Angela Principia
    Univ Bari Aldo Moro, Dept Emergency & Organ Transplant, Bari, Italy.
    Marzullo, Andrea
    Univ Bari Aldo Moro, Dept Emergency & Organ Transplant, Bari, Italy.
    Batista Borges, João
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Kings Coll London, Fac Sci & Med, Ctr Human & Appl Physiol Sci, London, England.
    Bayat, Sam
    Grenoble Alpes Univ, Synchrotron Radiat Biomed STROBE Lab, INSERM UA7, Amiens, France.
    Bravin, Alberto
    European Synchrotron Radiat Facil, Grenoble, France.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Perchiazzi, Gaetano
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Regional Behavior of Airspaces During Positive Pressure Reduction Assessed by Synchrotron Radiation Computed Tomography2019Ingår i: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 10, artikel-id 719Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Introduction: The mechanisms of lung inflation and deflation are only partially known. Ventilatory strategies to support lung function rely upon the idea that lung alveoli are isotropic balloons that progressively inflate or deflate and that lung pressure/volume curves derive only by the interplay of critical opening pressures, critical closing pressures, lung history, and position of alveoli inside the lung. This notion has been recently challenged by subpleural microscopy, magnetic resonance, and computed tomography (CT). Phase-contrast synchrotron radiation CT (PC-SRCT) can yield in vivo images at resolutions higher than conventional CT.

    Objectives: We aimed to assess the numerosity (ASden) and the extension of the surface of airspaces (ASext) in healthy conditions at different volumes, during stepwise lung deflation, in concentric regions of the lung. Methods: The study was conducted in seven anesthetized New Zealand rabbits. They underwent PC-SRCT scans (resolution of 47.7 mu m) of the lung at five decreasing positive end expiratory pressure (PEEP) levels of 12, 9, 6, 3, and 0 cmH(2)O during end-expiratory holds. Three concentric regions of interest (ROIs) of the lung were studied: subpleural, mantellar, and core. The images were enhanced by phase contrast algorithms. ASden and ASext were computed by using the Image Processing Toolbox for MatLab. Statistical tests were used to assess any significant difference determined by PEEP or ROI on ASden and ASext.

    Results: When reducing PEEP, in each ROI the ASden significantly decreased. Conversely, ASext variation was not significant except for the core ROI. In the latter, the angular coefficient of the regression line was significantly low.

    Conclusion: The main mechanism behind the decrease in lung volume at PEEP reduction is derecruitment. In our study involving lung regions laying on isogravitational planes and thus equally influenced by gravitational forces, airspace numerosity and extension of surface depend on the local mechanical properties of the lung.

  • 156.
    Scaramuzzo, Gaetano
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Ferrara Univ, Dept Morphol Surg & Expt Med, I-44121 Ferrara, Italy;.
    Broche, Ludovic
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Pellegrini, Mariangela
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Porra, Liisa
    Univ Helsinki, Dept Phys, FI-00014 Helsinki, Finland;Helsinki Univ Hosp, FI-00029 Helsinki, Finland.
    Derosa, Savino
    Bari Univ, Dept Emergency & Organ Transplant, I-70124 Bari, Italy.
    Tannoia, Angela Principia
    Bari Univ, Dept Emergency & Organ Transplant, I-70124 Bari, Italy.
    Marzullo, Andrea
    Bari Univ, Dept Emergency & Organ Transplant, I-70124 Bari, Italy.
    Borges, Joao Batista
    Kings Coll London, Fac Sci & Med, Ctr Human & Appl Physiol Sci, London WC2R 2LS, England.
    Bayat, Sam
    European Synchrotron Radiat Facil, F-38043 Grenoble, France;Univ Grenoble Alpes, Synchrotron Radiat Biomed STROBE Lab, INSERM UA7, F-38043 Grenoble, France.
    Bravin, Alberto
    European Synchrotron Radiat Facil, F-38043 Grenoble, France.
    Larsson, Anders
    Uppsala Univ, Dept Surg Sci, Hedenstierna Lab, S-75185 Uppsala, Sweden.
    Perchiazzi, Gaetano
    Uppsala Univ, Dept Surg Sci, Hedenstierna Lab, S-75185 Uppsala, Sweden;Uppsala Univ Hosp, Dept Anesthesia & Intens Care, S-75185 Uppsala, Sweden.
    The Effect of Positive End-Expiratory Pressure on Lung Micromechanics Assessed by Synchrotron Radiation Computed Tomography in an Animal Model of ARDS2019Ingår i: JOURNAL OF CLINICAL MEDICINE, ISSN 2077-0383, Vol. 8, nr 8, artikel-id 1117Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Modern ventilatory strategies are based on the assumption that lung terminal airspaces act as isotropic balloons that progressively accommodate gas. Phase contrast synchrotron radiation computed tomography (PCSRCT) has recently challenged this concept, showing that in healthy lungs, deflation mechanisms are based on the sequential de-recruitment of airspaces. Using PCSRCT scans in an animal model of acute respiratory distress syndrome (ARDS), this study examined whether the numerosity (ASnum) and dimension (ASdim) of lung airspaces change during a deflation maneuver at decreasing levels of positive end-expiratory pressure (PEEP) at 12, 9, 6, 3, and 0 cmH(2)O. Deflation was associated with significant reduction of ASdim both in the whole lung section (passing from from 13.1 +/- 2.0 at PEEP 12 to 7.6 +/- 4.2 voxels at PEEP 0) and in single concentric regions of interest (ROIs). However, the regression between applied PEEP and ASnum was significant in the whole slice (ranging from 188 +/- 52 at PEEP 12 to 146.4 +/- 96.7 at PEEP 0) but not in the single ROIs. This mechanism of deflation in which reduction of ASdim is predominant, differs from the one observed in healthy conditions, suggesting that the peculiar alveolar micromechanics of ARDS might play a role in the deflation process.

  • 157.
    Schilling, Thomas
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Kretzschmar, Moritz
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Hachenberg, T.
    Hedenstierna, Göran
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Kozian, Alf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    The immune response to one-lung-ventilation is not affected by repeated alveolar recruitment manoeuvres in pigs2013Ingår i: Minerva Anestesiologica, ISSN 0375-9393, E-ISSN 1827-1596, Vol. 79, nr 6, s. 590-603Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background. Acute lung injury after thoracic surgery relates to alveolar inflammation induced by one-lung ventilation (OLV) and surgical manipulation. However, alveolar recruitment manoeuvres (ARM), conventional ventilation, and airway manipulation may increase alveolar trauma. This study evaluates pulmonary immune effects of these co-factors in a porcine model. Methods. Twenty-two piglets (27.3 kg) were randomised to spontaneous breathing (N.=4), two-lung ventilation (TLV, N.=6), OLV with propofol (6 mg/kg/h, N.=6) or desflurane anesthesia (1MAC, N.=6). Mechanical ventilation settings were constant throughout the experiment: V-T=10 mL/kg, F1O2=0.4, PEEP=5 cmH(2)O. OLV was performed by left-sided bronchial blockade. Thoracic surgery was simulated for 60 min. ARM (airway pressure of 40 mbar for 10 s) was applied before and after each airway manipulation. Cytokines and mRNA-expression were assessed by immunoassays and semi-quantitative RT-PCR in alveolar lavage fluids, serum and tissue samples prior to and after OLV (TLV in controls). Results. Repetitive ARM and TLV induced no significant proinflammatory effects. OLV enhanced cytokine release but less with desflurane inhalation than propofol infusion (median (IQR) [pg/mL], dependent lung): Interleukin-8: TLV 44 (17) to 68 (35), propofol 82 (17) to 494 (231), desflurane 89 (30) to 282 (44). Likewise, serum cytokines were different: tumour necrosis factor-a: TLV 37 (13) to 62 (7), propofol 55 (39) to 94 (60), desflurane 43 (33) to 41 (25). Expression of interleukin-8-mRNA increased after OLV, but mRNA expression was not modulated by anesthetics. Conclusion. ARM, standard TLV and repetitive BAL do not additionally contribute to lung injury resulting from OLV for thoracic surgery in healthy porcine lungs. OLV induces expression of interleukin-8-mRNA in alveolar cells, which is not modulated by different anesthetic drugs.

  • 158.
    Sigmundsson, Thorir Svavar
    et al.
    Karolinska Univ Hosp, Dept Perioperat Med & Intens Care, Stockholm, Sweden.;Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Öhman, Tomas
    Karolinska Univ Hosp, Dept Perioperat Med & Intens Care, Stockholm, Sweden.;Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Hallbäck, Magnus
    Maquet Crit Care AB, Solna, Sweden..
    Redondo, Eider
    Hosp Navarra, Dept Intens Care Med, Pamplona, Spain..
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain..
    Wallin, Mats
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden.;Maquet Crit Care AB, Solna, Sweden..
    Oldner, Anders
    Karolinska Univ Hosp, Dept Perioperat Med & Intens Care, Stockholm, Sweden.;Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Sander, Caroline Hällsjö
    Karolinska Univ Hosp, Dept Perioperat Med & Intens Care, Stockholm, Sweden.;Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Björne, Håkan
    Karolinska Univ Hosp, Dept Perioperat Med & Intens Care, Stockholm, Sweden.;Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Performance of a capnodynamic method estimating effective pulmonary blood flow during transient and sustained hypercapnia2018Ingår i: Journal of clinical monitoring and computing, ISSN 1387-1307, E-ISSN 1573-2614, Vol. 32, nr 2, s. 311-319Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The capnodynamic method is a minimally invasive method continuously calculating effective pulmonary blood flow (COEPBF), equivalent to cardiac output when intra pulmonary shunt flow is low. The capnodynamic equation joined with a ventilator pattern containing cyclic reoccurring expiratory holds, provides breath to breath hemodynamic monitoring in the anesthetized patient. Its performance however, might be affected by changes in the mixed venous content of carbon dioxide (CvCO2). The aim of the current study was to evaluate COEPBF during rapid measurable changes in mixed venous carbon dioxide partial pressure (PvCO2) following ischemia-reperfusion and during sustained hypercapnia in a porcine model. Sixteen pigs were submitted to either ischemia-reperfusion (n = 8) after the release of an aortic balloon inflated during 30 min or to prolonged hypercapnia (n = 8) induced by adding an instrumental dead space. Reference cardiac output (CO) was measured by an ultrasonic flow probe placed around the pulmonary artery trunk (COTS). Hemodynamic measurements were obtained at baseline, end of ischemia and during the first 5 min of reperfusion as well as during prolonged hypercapnia at high and low CO states. Ischemia-reperfusion resulted in large changes in PvCO2, hemodynamics and lactate. Bias (limits of agreement) was 0.7 (-0.4 to 1.8) L/min with a mean error of 28% at baseline. COEPBF was impaired during reperfusion but agreement was restored within 5 min. During prolonged hypercapnia, agreement remained good during changes in CO. The mean polar angle was -4.19A degrees (-8.8A degrees to 0.42A degrees). Capnodynamic COEPBF is affected but recovers rapidly after transient large changes in PvCO2 and preserves good agreement and trending ability during states of prolonged hypercapnia at different levels of CO.

  • 159.
    Simm, Mikael
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Söderberg, Ewa
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Biokemisk struktur och funktion.
    Castegren, Markus
    Department of Anaesthesia, Intensive Care & Surgical Services, Karolinska University Hospital, Huddinge, Stockholm, Sweden..
    Nilsen, Tom
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Biokemisk struktur och funktion.
    Eriksson, Mats
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Lipcsey, Miklós
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Performance of plasma calprotectin as a biomarker of early sepsis: a pilot study2016Ingår i: Biomarkers in Medicine, ISSN 1752-0363, E-ISSN 1752-0371, Vol. 10, nr 8, s. 811-818Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    AIM: To determine the performance of plasma calprotectin as a marker of sepsis on intensive care unit (ICU) admission and as a marker of mortality day 30 post-ICU admission.

    MATERIALS & METHODS: Consecutive ICU patients were allocated to: sepsis (n = 15), postoperative inflammation (n = 23) and intoxication without inflammation (n = 7) groups.

    RESULTS: Calprotectin was 4.3 (2.6-8.2; mg/l; median [interquartile range]) in the sepsis, 2.8 (1.6-4.4) in the postoperative and 0.7 (0.4-1.6) in the intoxication groups. Area under the receiver operating characteristic curve for sepsis versus intoxication group was: 0.95, for sepsis versus postoperative groups: 0.65 and for survivors versus nonsurvivors: 0.70.

    CONCLUSION: Calprotectin was a sensitive marker of systemic inflammation, is a potential sepsis marker and performed well as mortality predictor in this pilot study.

  • 160.
    Skorup, Paul
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Infektionssjukdomar.
    Maudsdotter, Lisa
    Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University.
    Lipcsey, Miklós
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk kemi.
    Sjölin, Jan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Infektionssjukdomar.
    Mode of Bacterial Killing Affects the Inflammatory Response and Associated Organ Dysfunctions in a Porcine E. coli Intensive Care Sepsis ModelManuskript (preprint) (Övrigt vetenskapligt)
  • 161.
    Skorup, Paul
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Infektionssjukdomar.
    Wilske, Frida
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Infektionssjukdomar.
    Hanslin, Katja
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk kemi.
    Lipcsey, Miklós
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Sjölin, Jan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Infektionssjukdomar. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Enhanced Bacterial Clearance at a Secondary Sepsis Challenge in an Endotoxin-tolerant Porcine Intensive Care ModelManuskript (preprint) (Övrigt vetenskapligt)
  • 162.
    Sperber, Jesper
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Centrum för klinisk forskning i Sörmland (CKFD). Centre for Clinical Research Sörmland, Department of Anesthesiology & Intensive Care Mälarsjukhuset, SE-631 88 Eskilstuna, Sweden.
    Nyberg, Axel
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Centrum för klinisk forskning i Sörmland (CKFD). Centre for Clinical Research Sörmland, Department of Anesthesiology & Intensive Care Mälarsjukhuset, SE-631 88 Eskilstuna, Sweden.
    Lipcsey, Miklós
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Melhus, Åsa
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk mikrobiologi.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Biokemisk struktur och funktion.
    Sjölin, Jan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Infektionssjukdomar.
    Castegren, Markus
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Centrum för klinisk forskning i Sörmland (CKFD). Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Perioperative Medicine and Intensive Care, Karolinska University Hospital and CLINTEC, Karolinska Institute, Stockholm, Sweden.
    Protective ventilation reduces Pseudomonas aeruginosa growth in lung tissue in a porcine pneumonia model2017Ingår i: Intensive & Critical Care Nursing, ISSN 0964-3397, E-ISSN 1532-4036, Vol. 5, artikel-id 40Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Mechanical ventilation with positive end expiratory pressure and low tidal volume, i.e. protective ventilation, is recommended in patients with acute respiratory distress syndrome. However, the effect of protective ventilation on bacterial growth during early pneumonia in non-injured lungs is not extensively studied. The main objectives were to compare two different ventilator settings on Pseudomonas aeruginosa growth in lung tissue and the development of lung injury.

    METHODS: A porcine model of severe pneumonia was used. The protective group (n = 10) had an end expiratory pressure of 10 cm H2O and a tidal volume of 6 ml x kg-1. The control group (n = 10) had an end expiratory pressure of 5 cm H2O and a tidal volume of 10 ml x kg-1. 1011 colony forming units of Pseudomonas aeruginosa were inoculated intra-tracheally at baseline, after which the experiment continued for 6 h. Two animals from each group received only saline, and served as sham animals. Lung tissue samples from each animal were used for bacterial cultures and wet-to-dry weight ratio measurements.

    RESULTS: The protective group displayed lower numbers of Pseudomonas aeruginosa (p < 0.05) in the lung tissue, and a lower wet-to-dry ratio (p < 0.01) than the control group. The control group deteriorated in arterial oxygen tension/inspired oxygen fraction, whereas the protective group was unchanged (p < 0.01).

    CONCLUSIONS: In early phase pneumonia, protective ventilation with lower tidal volume and higher end expiratory pressure has the potential to reduce the pulmonary bacterial burden and the development of lung injury.

  • 163.
    Strandberg, Gunnar
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk kemi.
    Lipcsey, Miklós
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Eriksson, Mats
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Comparison of Intraosseous, Arterial, and Venous Blood Sampling for Laboratory Analysis in Hemorrhagic Shock2019Ingår i: Clinical Laboratory, ISSN 1433-6510, Vol. 65, nr 7, s. 1169-1177Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Intraosseous (IO) access is often indicated for administration of drugs and fluids in emergencies when venous access is challenging. There is no consensus regarding whether and which laboratory analyses may be performed on IO aspirates, and research on hemodynamically unstable subjects is limited.

    Methods: Twelve anesthetized pigs were sampled from IO, venous, and arterial accesses during stable circulation and after hemorrhage corresponding to 20% and 40% of the blood volume. Samples were analyzed for blood gases and acid-base status, electrolytes, hematocrit, creatinine, glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (γ-GT), alkaline phosphatase (ALP), and creatine kinase (CK).

    Results: Average differences of blood gases and acid-base parameters, sodium, creatinine, hematocrit, ALT, and γ-GT and between IO and venous samples were small at baseline and after hemorrhage while differences for lactate and glucose increased with hypovolemia. Both IO-arterial and venoarterial differences in acid-base parameters increased with hypovolemia. Dispersions of differences were often large.

    Conclusions: Average levels of blood gases, acid base parameters, hematocrit, CK, AST, γ-GT, creatinine, and ALT, but not lactate and glucose, were similar in IO and venous samples in hypovolemia. However, precision was limited, indicating that IO test results should be confirmed when other vascular access is established, and that analysis of IO samples should be limited to acute situations and not used for detailed diagnostics in this setting.

  • 164.
    Strandberg, Gunnar
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Lipcsey, Miklós
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Eriksson, Mats B.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Lubenow, Norbert
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi, Klinisk immunologi.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Biokemisk struktur och funktion.
    Analysis of Thromboelastography, PT, APTT and Fibrinogen in Intraosseous and Venous Samples: An Experimental Study2016Ingår i: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, ISSN 1757-7241, E-ISSN 1757-7241, Vol. 24, artikel-id 131Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background:Laboratory analysis of coagulation is often important in emergencies. If vascular access is challenging,intraosseous catheterization may be necessary for treatment. We studied the analysis of coagulation parameters inintraosseous aspirate during stable conditions and after major haemorrhage in a porcine model.Methods:Ten anesthetized pigs received central venous and intraosseous catheters and samples were taken foranalysis of thromboelastography (TEG), prothrombin time (PT), activated partial thromboplastin time (APTT) andfibrinogen concentration. Analyses were repeated after removal of 50 % of the calculated blood volume andresuscitation with crystalloid. Intraosseous and venous values were compared.Results:Bleeding and resuscitation resulted in haemodilution and hypotension. Median TEG reaction time wasshorter in intraosseous than in venous samples before (1.6 vs 4.6 min) and after (1.6 vs 4.7 min) haemodilution.Median maximal amplitude was smaller in intraosseous samples at baseline (68.3 vs 76.4 mm). No major differenceswere demonstrated for the other TEG parameters. The intraosseous samples often coagulated in vitro, makinganalysis of PT, APTT and fibrinogen difficult. After haemodilution, TEG maximal amplitude andα-angle, andfibrinogen concentration, were decreased and PT increased.Discussion:The intraosseous samples were clinically hypercoagulable and the TEG demonstrated a shortenedreaction time. The reason for this may hypothetically be found in the composition of the IO aspirate or in thesampling technique. After 50 % haemorrhage and haemodilution, a clinically relevant decrease in fibrinogenconcentration and a lower TEG maximal amplitude were observed.Conclusions:Although the sample is small, these data indicate that intraosseous samples are hypercoagulable,which may limit their usefulness for coagulation studies. Major haemodilution only moderately affected the studied parameters.

  • 165.
    Strassmann, Stephan
    et al.
    Witten Herdecke Univ Hosp, Cologne Merheim Hosp, Dept Pneumol & Crit Care Med, ARDS & ECMO Ctr,Kliniken Stadt Koln gGmbH, Ostmerheimer Str 200, D-51109 Cologne, Germany.
    Merten, Michaela
    Witten Herdecke Univ Hosp, Cologne Merheim Hosp, Dept Pneumol & Crit Care Med, ARDS & ECMO Ctr,Kliniken Stadt Koln gGmbH, Ostmerheimer Str 200, D-51109 Cologne, Germany.
    Schäfer, Simone
    Witten Herdecke Univ Hosp, Cologne Merheim Hosp, Dept Pneumol & Crit Care Med, ARDS & ECMO Ctr,Kliniken Stadt Koln gGmbH, Ostmerheimer Str 200, D-51109 Cologne, Germany.
    de Moll, Jonas
    Witten Herdecke Univ Hosp, Cologne Merheim Hosp, Dept Pneumol & Crit Care Med, ARDS & ECMO Ctr,Kliniken Stadt Koln gGmbH, Ostmerheimer Str 200, D-51109 Cologne, Germany.
    Brodie, Daniel
    Columbia Univ Coll Phys & Surg, Div Pulm Allergy & Crit Care, New York Presbyterian Hosp, 630 W 168th St, New York, NY 10032 USA.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Windisch, Wolfram
    Witten Herdecke Univ Hosp, Cologne Merheim Hosp, Dept Pneumol & Crit Care Med, ARDS & ECMO Ctr,Kliniken Stadt Koln gGmbH, Ostmerheimer Str 200, D-51109 Cologne, Germany.
    Karagiannidis, Christian
    Witten Herdecke Univ Hosp, Cologne Merheim Hosp, Dept Pneumol & Crit Care Med, ARDS & ECMO Ctr,Kliniken Stadt Koln gGmbH, Ostmerheimer Str 200, D-51109 Cologne, Germany.
    Impact of sweep gas flow on extracorporeal CO2 removal (ECCO2R)2019Ingår i: Intensive Care Medicine Experimental, ISSN 1646-2335, E-ISSN 2197-425X, Vol. 7, artikel-id 17Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Veno-venous extracorporeal carbon dioxide (CO2) removal (vv-ECCO2R) is increasingly being used in the setting of acute respiratory failure. Blood flow rates range in clinical practice from 200mL/min to more than 1500mL/min, and sweep gas flow rates range from less than 1 to more than 10L/min. The present porcine model study was aimed at determining the impact of varying sweep gas flow rates on CO2 removal under different blood flow conditions and membrane lung surface areas.

    Methods: Two different membrane lungs, with surface areas of 0.4 and 0.8m(2), were used in nine pigs with experimentally-induced hypercapnia. During each experiment, the blood flow was increased stepwise from 300 to 900 mL/min, with further increases up to 1800 mL/min with the larger membrane lung in steps of 300 mL/min. Sweep gas was titrated under each condition from 2 to 8L/min in steps of 2 L/min. Extracorporeal CO2 elimination was normalized to a PaCO2 of 45 mmHg before the membrane lung.

    Results: Reversal of hypercapnia was only feasible when blood flow rates above 900mL/min were used with a membrane lung surface area of at least 0.8m(2). The membrane lung with a surface of 0.4m(2) allowed a maximum normalized CO2 elimination rate of 416mL/min with 8L/min sweep gas flow and 900mLbloodflow/min. The increase in sweep gas flow from 2 to 8L/min increased normalized CO2 elimination from 35 +/- 5 to 41 +/- 6 with 900mLbloodflow/min, whereas with lower blood flow rates, any increase was less effective, levelling out at 4Lsweepgasflow/min. The membrane lung with a surface area of 0.8 m(2) allowed a maximum normalized CO2 elimination rate of 101 +/- 12 mL/min with increasing influence of sweep gas flow. The delta of normalized CO2 elimination increased from 4 +/- 2 to 26 +/- 7 mL/min with blood flow rates being increased from 300 to 1800 mL/min, respectively.

    Conclusions: The influence of sweep gas flow on the CO2 removal capacity of ECCO2R systems depends predominantly on blood flow rate and membrane lung surface area. In this model, considerable CO2 removal occurred only with the larger membrane lung surface of 0.8m(2) and when blood flow rates of >= 900mL/min were used.

  • 166.
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    New modes of assisted mechanical ventilation2014Ingår i: Medicina Intensiva, ISSN 0210-5691, E-ISSN 1578-6749, Vol. 38, nr 4, s. 249-260Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent major advances in mechanical ventilation have resulted in new exciting modes of assisted ventilation. Compared to traditional ventilation modes such as assisted-controlled ventilation or pressure support ventilation, these new modes offer a number of physiological advantages derived from the improved patient control over the ventilator. By implementing advanced closed-loop control systems and using information on lung mechanics, respiratory muscle function and respiratory drive, these modes are specifically designed to improve patient-ventilator synchrony and reduce the work of breathing. Depending on their specific operational characteristics, these modes can assist spontaneous breathing efforts synchronically in time and magnitude, adapt to changing patient demands, implement automated weaning protocols, and introduce a more physiological variability in the breathing pattern. Clinicians have now the possibility to individualize and optimize ventilatory assistance during the complex transition from fully controlled to spontaneous assisted ventilation. The growing evidence of the physiological and clinical benefits of these new modes is favoring their progressive introduction into clinical practice. Future clinical trials should improve our understanding of these modes and help determine whether the claimed benefits result in better outcomes. (C) 2013 Elsevier Espana, S.L. and SEMICYUC. All rights reserved.

  • 167.
    Suarez-Sipmann, Fernando
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Bohm, Stephan H.
    Tusman, Gerardo
    Volumetric capnography: the time has come2014Ingår i: Current Opinion in Critical Care, ISSN 1070-5295, E-ISSN 1531-7072, Vol. 20, nr 3, s. 333-339Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Purpose of review This review article summarizes the recent advances in electrical impedance tomography (EIT) related to cardiopulmonary imaging and monitoring on the background of the 30-year development of this technology. Recent findings EIT is expected to become a bedside tool for monitoring and guiding ventilator therapy. In this context, several studies applied EIT to determine spatial ventilation distribution during different ventilation modes and settings. EIT was increasingly combined with other signals, such as airway pressure, enabling the assessment of regional respiratory system mechanics. EIT was for the first time used prospectively to define ventilator settings in an experimental and a clinical study. Increased neonatal and paediatric use of EIT was noted. Only few studies focused on cardiac function and lung perfusion. Advanced radiological imaging techniques were applied to assess EIT performance in detecting regional lung ventilation. New approaches to improve the quality of thoracic EIT images were proposed. EIT is not routinely used in a clinical setting, but the interest in EIT is evident. The major task for EIT research is to provide the clinicians with guidelines how to conduct, analyse and interpret EIT examinations and combine them with other medical techniques so as to meaningfully impact the clinical decision-making.

  • 168.
    Suarez-Sipmann, Fernando
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Hosp Univ Princesa, Dept Crit Care Med, Diego de Leon 62, Madrid 28006, Spain;Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain.
    Ferrando, Carlos
    Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain;Inst Invest Biomed August Pi i Sunyer IDIBAPS, Hosp Clin, Dept Anesthesiol & Crit Care, Barcelona, Spain.
    Villar, Jesus
    Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain;Hosp Univ Dr Negrin, Res Unit, MODERN, Las Palmas Gran Canaria, Spain;St Michaels Hosp, Li Ka Shing Knowledge Inst, Keenan Res Ctr Biomed Sci, Toronto, ON, Canada.
    PEEP titration guided by transpulmonary pressure: lessons from a negative trial2019Ingår i: Journal of Thoracic Disease, ISSN 2072-1439, E-ISSN 2077-6624, Vol. 11, s. S1957-S1962Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Since the first description of the acute respiratory distress syndrome (ARDS) by the landmark paper of Ashbaugh et al. (1), the adequate use of positive end-expiratory pressure (PEEP) has been surrounded by a vivid controversy. This stems from the fact that its beneficial effects on oxygenation by re-aerating collapsed or flooded airspaces, may be counterbalanced by potential adverse effects on hemodynamics and on the risk of increasing lung tissue mechanical stress. The vast amount of clinical and experimental reports over the last five decades, adequately reflect this “PEEP paradox”: the simultaneous effects of PEEP on gas exchange, lung mechanics and hemodynamics can have competing beneficial or deleterious consequences even in similar clinical or experimental conditions. Thus, the effects of PEEP are complex and difficult to predict, more so in the heterogeneous ARDS lung, and depend not only on the selected level but also on how this level interacts and modifies the lung status. For instance, a high PEEP level may improve oxygenation but if it not associated to significant recruitment of collapsed lung regions can increase non-dependent lung overdistension.

    Although in clinical practice the changes in oxygenation remain the main driver for PEEP selection, the progressive awareness that mechanical ventilation can aggravate lung injury has shifted the interest to the potential lung-protective effects of PEEP, already recognized in early experimental studies (2). By preventing end-expiratory lung collapse and increasing end-expiratory lung volume, PEEP can counteract the two major mechanisms related to ventilation-induced lung injury (VILI) (3). On the one hand, it reduces or avoids the strain resulting from cyclic recruitment-derecruitment in boundary-regions of the mid-dependent regions, between collapsed and aerated lung. On the other hand, it promotes a more homogeneous distribution of ventilation by increasing the size of the functional lung thereby reducing the cyclic inflation stress of the non-dependent lung. Lung-protective ventilation (LPV) strategies aimed at reducing the mechanical stress on the lung, are the only therapeutic interventions that have improved ARDS outcome, and although the ultimate contribution of VILI to mortality is not known, it is important to emphasize that only a fifth of ARDS patients die with refractory hypoxemia (4). However, the definitive role of PEEP in lung protection has been difficult to establish in clinical studies (5). Dichotomous high-vs-low PEEP study designs, failure to confirm patient responsiveness to PEEP (6), and absence of proper PEEP individualization are among the reasons behind this lacking evidence.

  • 169.
    Suarez-Sipmann, Fernando
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Santos, A.
    Peces-Barba, G.
    Bohm, S. H.
    Gracia, J. L.
    Calderón, P.
    Tusman, G.
    Pulmonary artery pulsatility is the main cause of cardiogenic oscillations2013Ingår i: Journal of clinical monitoring and computing, ISSN 1387-1307, E-ISSN 1573-2614, Vol. 27, nr 1, s. 47-53Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The genesis of cardiogenic oscillations, i.e. The small waves in airway pressure (COSpaw) and flow (COSflow) signals recorded at the airway opening is under debate. We hypothesized that these waves are originated from cyclic changes in pulmonary artery (PA) pressure and flow but not from the physical transmission of heartbeats onto the lungs. The aim of this study was to test this hypothesis. In 10 anesthetized pigs, COS were evaluated during expiratory breath-holds at baseline with intact chest and during open chest conditions at: (1) close contact between heart and lungs; (2) no heart-lungs contact by lifting the heart apex outside the thoracic cavity; (3) PA clamping at the main trunk during 10 s; and (4) during manual massage after cardiac arrest maintaining the heart apex outside the thorax, with and without PA clamping. Baseline COSpaw and COSflow amplitude were 0.70 ± 0.08 cmH2O and 0.51 ± 0.06 L/min, respectively. Both COS amplitude decreased during open chest conditions in step 1 and 2 (p &lt; 0.05). However, COSpaw and COSflow amplitude did not depend on whether the heart was in contact or isolated from the surrounding lung parenchyma. COSpaw and COSflow disappeared when pulmonary blood flow was stopped after clamping PA in all animals. Manual heart massages reproduced COS but they disappeared when PA was clamped during this maneuver. The transmission of PA pulsatilty across the lungs generates COSpaw and COSflow measured at the airway opening. This information has potential applications for respiratory monitoring.

  • 170.
    Suarez-Sipmann, Fernando
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk fysiologi.
    Santos, Arnoldo
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Boehm, Stephan H.
    Borges, Joao Batista
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk fysiologi.
    Hedenstierna, Göran
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk fysiologi.
    Tusman, Gerardo
    Corrections of Enghoffs dead space formula for shunt effects still overestimate Bohr's dead space2013Ingår i: Respiratory Physiology & Neurobiology, ISSN 1569-9048, E-ISSN 1878-1519, Vol. 189, nr 1, s. 99-105Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Dead space ratio is determined using Enghoffs modification (VDB-E/V-T) of Bohr's formula (V-DBohr/V-T) in which arterial is used as a surrogate of alveolar PCO2. In presence of intrapulmonary shunt Enghoffs approach overestimates dead space. In 40 lung-lavaged pigs we evaluated the Kuwabara's and Niklason's algorithms to correct for shunt effects and hypothesized that corrected VDB-E/V-T should provide similar values as V-DBohr/V-T. We analyzed 396 volumetric capnograms and arterial and mixed-venous blood samples to calculate V-DBohr/V-T and VDB-E/V-T. Thereafter, we corrected the latter for shunt effects using Kuwabara's (K) VDB-E/V-T and Niklason's (N) VDB-E/V-T algorithms. Uncorrected VDB-E/V-T (mean +/- SD of 0.70 +/- 0.10) overestimated V-DBohr/V-T (0.59 +/- 0.12) (p < 0.05), over the entire range of shunts. Mean (K) VDB-E/V-T was significantly higher than V-DBor/V-T (0.67 +/- 0.08, bias 0.085, limits of agreement 0.232 to 0.085; p< 0.05) whereas (N)VDB-E/V-T showed a better correction for shunt effects (0.64 +/- 0.09, bias 0.048, limits of agreement -0.168 to 0.072; p < 0.05). Neither Kuwabara's nor Niklason's algorithms were able to correct EnghofFs dead space formula for shunt effects. 

  • 171.
    Söderberg, Ewa
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Eriksson, Mats
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper.
    Lipcsey, Miklos
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    The impact of hydrocortisone treatment on neutrophil gelatinase-associated lipocalin release in porcine endotoxemic shock2017Ingår i: Intensive Care Medicine Experimental, ISSN 1646-2335, E-ISSN 2197-425X, Vol. 5, artikel-id 4Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: A key feature of sepsis is systemic inflammatory activation that could be counteracted by steroids. In this experimental model of systemic inflammation, we sought to investigate whether septic neutrophil activation, evaluated by the plasma levels of neutrophil gelatinase-associated protein (NGAL), is modulated by the timing of hydrocortisone treatment.

    METHODS: Sixteen anesthetized pigs were allocated to one of four equally sized groups. Three of these groups received endotoxin at 2 μg × kg(-1) × h(-1) for 6 h so as to induce endotoxemic shock. Hydrocortisone (5 mg × kg(-1)) was administered intravenously before endotoxemic challenge, or at the onset of endotoxemic shock. Endotoxemic pigs not receiving hydrocortisone and non-endotoxemic pigs served as control groups. Physiologic variables, hematology, and biochemistry, including plasma NGAL, were measured repeatedly.

    RESULTS: Hydrocortisone treatment prior to endotoxemia attenuated some inflammatory, hematological, circulatory, and metabolic manifestations of shock (i.e., higher white blood cell count, higher mean arterial pressure, lower heart rate and mean pulmonary arterial pressure, higher left ventricular stroke work index, higher base excess). Endotoxemic shock increased plasma NGAL (p < 0.001). In pigs given hydrocortisone before the endotoxin infusion, plasma NGAL was lower as compared to those given hydrocortisone at endotoxemic shock (p < 0.05). Plasma NGAL levels correlated inversely to neutrophil granulocyte counts (rho = -0.65) but not to urine output (rho = -0.10) at the end of the experiment.

    CONCLUSIONS: The increase in plasma NGAL is counteracted by hydrocortisone administration prior to endotoxemia; concomitantly, this treatment was associated with less expressed circulatory derangement. Urine NGAL did not differ between the groups, suggesting that the NGAL response was not primarily related to kidney injury.

  • 172.
    Sütterlin, Robert
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Frykholm, Peter
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Lo Mauro, Antonella
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Gandolfi, Stefano
    Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.
    Priori, Rita
    Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Aliverti, Andrea
    Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.
    Influence of Tracheal Obstruction on the Efficacy of Superimposed High-frequency Jet Ventilation and Single-frequency Jet Ventilation2015Ingår i: Anesthesiology, ISSN 0003-3022, E-ISSN 1528-1175, Vol. 123, nr 10, s. 799-809, artikel-id doi:10.1097/ALN.0000000000000818Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background

    Superimposed high frequency jet ventilation (SHFJV) has been used successfully in selected patients with severe central airway obstruction undergoing airway interventions.

    We sought to systematically describe the efficacy of SHFJV in relation to obstruction and the high frequency component (fHF) in a model of tracheal stenosis.

    Methods

    Ten anesthetized animals (25-31.5kg) were alternately ventilated with SHFJV (low frequency 16min-1, random fHF) at a set of different fHF from 50-600min-1. Tracheal obstruction was created using exchangeable stents with different inner diameter (2, 4, 6, 8mm) that were inserted into the trachea. Chest wall volume was measured using optoelectronic plethysmography, airway pressures were recorded and blood gases were analyzed repeatedly.

    Results

    Stent ID reduction from 8 to 2mm resulted in an increase of ∆EEVCW by up to 3x (e.g. 323 [255 - 410] ml vs 106 [81 - 138] ml at fHF=100 min-1). At the same time, VT decreased by up to 4.2x (e.g. 477 [434 – 524] ml vs 114 [79 – 165] ml). PaO2 and paCO2 remained at acceptable levels for 4-8 mm stent ID but CO2 removal became suddenly impaired at 2mm stent ID (paCO2>12 kPa). Pre-stenotic airway pressure monitoring was accurate at 8mm stent ID, but overestimation of peak inspiratory pressure (PIP) up to 2x and underestimation of PEEP up to 19x was observed at 2mm stent ID.

    Conclusion

    SHFJV was able to maintain oxygenation and carbon dioxide removal over a wide range of obstructions, despite decreasing VT and successive air trapping. At 2 mm stent ID, only carbon dioxide removal became insufficient.

  • 173.
    Sütterlin, Robert
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Lo Mauro, Antonella
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.
    Gandolfi, Stefano
    Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.
    Priori, Rita
    Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.
    Aliverti, Andrea
    Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.
    Frykholm, Peter
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Efficacy of Superimposed High Frequency Jet Ventilation and High Frequency Jet Ventilation in an Animal Model of Tracheal Obstruction2014Ingår i: Anesthesiology, ISSN 0003-3022, E-ISSN 1528-1175Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background

    Superimposed high frequency jet ventilation (SHFJV) and high-frequency jet ventilation (HJFV) are widely used for airway interventions using rigid bronchoscopy. SHFJV was found to provide higher lung volume and better gas exchange than HFJV in unobstructed airways.

    We hypothesized that, also in the presence of airway obstruction, SHFJV would provide higher lung volumes, better oxygenation and more effective CO2 removal than HFJV.

    Methods

    In a porcine model, we used a stent with ID 4 mm to create tracheal obstruction. The anesthetized animals (25-31.5kg) were alternately ventilated with SHFJV (low frequency 16min-1, combined with a high frequency fHF) and HFJV (solely fHF) at a set of different fHF from 50-600min-1. Chest wall volume changes were measured with opto-electronic plethysmography, airway pressures were registered continuously and arterial blood gases were obtained repeatedly.

    Results

    SHFJV provided higher ∆EEVCW than HFJV with a difference between both modes of 129 ml (fHF=50min-1) to 62 ml (fHF=400min-1). Tidal volume (VT) was always greater than 213 ml with SHFJV, but with HFJV, increasing fHF reduced VT from 112 (97-130) ml at fHF=50 min-1 to negligible values at fHF>150 min-1.

    In analogy, SHFJV provided paO2 of >30 kPa and acceptable CO2 removal for all fHF, whereas fHF>150 min-1 resulted in severe hypoxia and hypercarbia during HFJV.

    Conclusion

    SHFJV effectively increased lung volumes and maintained gas exchange compared with HFJV. SHFJV may be a safer option than HFJV in laser surgery, where low FiO2 is required. HFJV with frequencies >100-150 min-1 should not be used in severe airway obstruction.

  • 174.
    Thomassen, Sisse Anette
    et al.
    Aalborg Univ Hosp, Dept Anaesthesiol & Intens Care Med, Hobrovej 18-22, DK-9100 Aalborg, Denmark.;Aalborg Univ, Dept Clin Med, Aalborg, Denmark..
    Kjaergaard, Benedict
    Aalborg Univ, Dept Clin Med, Aalborg, Denmark.;Aalborg Univ Hosp, Dept Cardiothorac Surg, Aalborg, Denmark..
    Sorensen, Preben
    Aalborg Univ, Dept Clin Med, Aalborg, Denmark.;Aalborg Univ Hosp, Dept Neurosurg, Aalborg, Denmark..
    Andreasen, Jan Jesper
    Aalborg Univ, Dept Clin Med, Aalborg, Denmark.;Aalborg Univ Hosp, Dept Cardiothorac Surg, Aalborg, Denmark..
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Rasmussen, Bodil Steen
    Aalborg Univ Hosp, Dept Anaesthesiol & Intens Care Med, Hobrovej 18-22, DK-9100 Aalborg, Denmark.;Aalborg Univ, Dept Clin Med, Aalborg, Denmark..
    Regional muscle tissue saturation is an indicator of global inadequate circulation during cardiopulmonary bypass: a randomized porcine study using muscle, intestinal and brain tissue metabolomics2017Ingår i: Perfusion, ISSN 0267-6591, E-ISSN 1477-111X, Vol. 32, nr 3, s. 192-199Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Muscle tissue saturation (StO(2)) measured with near-infrared spectroscopy has generally been considered a measurement of the tissue microcirculatory condition. However, we hypothesized that StO2 could be more regarded as a fast and reliable measure of global than of regional circulatory adequacy and tested this with muscle, intestinal and brain metabolomics at normal and two levels of low cardiopulmonary bypass blood flow rates in a porcine model. Methods: Twelve 80 kg pigs were connected to normothermic cardiopulmonary bypass with a blood flow of 60 mL/kg/min for one hour, reduced randomly to 47.5 mL/kg/min (Group I) or 35 mL/kg/min (Group II) for one hour followed by one hour of 60 mL/kg/min in both groups. Regional StO(2) was measured continuously above the musculus gracilis (non-cannulated leg). Metabolomics were obtained by brain tissue oxygen monitoring system (Licox) measurements of the brain and microdialysis perfusate from the muscle, intestinal mucosa and brain. A non-parametric statistical method was used. Results: The systemic parameters showed profound systemic ischaemia during low CPB blood flow. StO(2) did not change markedly in Group I, but in Group II, StO(2) decreased immediately when blood flow was reduced and, furthermore, was not restored despite blood flow being normalized. Changes in the metabolomics from the muscle, colon and brain followed the changes in StO(2). Conclusion: We found, in this experimental cardiopulmonary bypass model, that StO(2) reacted rapidly when the systemic circulation became inadequate and, furthermore, reliably indicate insufficient global tissue perfusion even when the systemic circulation was restored after a period of systemic hypoperfusion.

  • 175. Thomassen, Sisse Anette
    et al.
    Kjærgaard, Benedict
    Olsen Alstrup, Aage Kristian
    Munk, Ole Lajord
    Frøkiær, Jørgen
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Rasmussen, Bodil Steen
    Muscle Tissue Saturation Compared With Muscle Tissue Perfusion During Low Blood Flows: An Experimental Study.2017Ingår i: Journal of Cardiothoracic and Vascular Anesthesia, ISSN 1053-0770, E-ISSN 1532-8422, Vol. 31, nr 6, s. 2065-2071Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVE: To investigate whether changes in muscle tissue perfusion measured with positron emission tomography would be reflected by parallel changes in muscle tissue oxygen saturation (StO2) measured using near-infrared spectroscopy during high and low blood flow levels achieved using cardiopulmonary bypass (CPB) in an animal model.

    DESIGN: A prospective, randomized study.

    SETTING: Research laboratory, single institution.

    PARTICIPANTS: Eight pigs (69-71 kg).

    INTERVENTIONS: In anesthetized pigs, normothermic CPB was established with a blood flow of 60 mL/kg/min for 1 hour. Thereafter, a low blood flow of either 47.5 or 35 mL/kg/min was applied for 1 hour followed by a blood flow of 60 mL/kg/min for an additional hour. Regional StO2 was measured continuously by placing a near-infrared spectroscopy electrode on the skin above the gracilis muscle of the noncannulated back leg. Muscle tissue perfusion was measured using positron emission tomography with (15)O-labeled water during spontaneous circulation and the different CPB blood flows. Systemic oxygen consumption was estimated by measurement of venous saturation and lactate levels.

    MEASUREMENTS AND MAIN RESULTS: The results showed profound systemic ischemia during low CPB blood flow. StO2 remained high until muscle tissue perfusion decreased to about 50%, after which StO2 paralleled the linear decrease in muscle tissue perfusion.

    CONCLUSION: In an experimental CPB animal model, StO2 was stable until muscle tissue perfusion was reduced by about 50%, and at lower blood flow levels, there was almost a linear relationship between StO2 and muscle tissue perfusion.

  • 176.
    Thorsted, Anders
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    Bouchene, Salim
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    Tano, Eva
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Infektionsmedicin. Uppsala Univ Hosp, Sect Clin Microbiol & Infect Med, Dept Med Sci, Uppsala, Sweden.
    Castegren, Markus
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Infektionssjukdomar. Karolinska Univ Hosp, Div Perioperat Med & Intens Care, Stockholm, Sweden;Karolinska Inst, Dept Clin Sci Intervent & Technol, Stockholm, Sweden.
    Lipcsey, Miklós
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala Univ Hosp, Dept Surg Sci, Sect Anesthesiol & Intens Care, Hedenstierna Lab, Uppsala, Sweden.
    Sjölin, Jan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Infektionssjukdomar. Uppsala Univ Hosp, Infect Dis Sect, Dept Med Sci, Uppsala, Sweden.
    Karlsson, Mats O
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    Friberg, Lena E.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    Nielsen, Elisabet I.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaceutisk biovetenskap.
    A non-linear mixed effect model for innate immune response: In vivo kinetics of endotoxin and its induction of the cytokines tumor necrosis factor alpha and interleukin-62019Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 14, nr 2, artikel-id e0211981Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Endotoxin, a component of the outer membrane of Gram-negative bacteria, has been extensively studied as a stimulator of the innate immune response. However, the temporal aspects and exposure-response relationship of endotoxin and resulting cytokine induction and tolerance development is less well defined. The aim of this work was to establish an in silico model that simultaneously captures and connects the in vivo time-courses of endotoxin, tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and associated tolerance development. Data from six studies of porcine endotoxemia in anesthetized piglets (n = 116) were combined and used in the analysis, with purified endotoxin (Escherichia coli O111: B4) being infused intravenously for 1-30 h in rates of 0.063-16.0 mu g/kg/h across studies. All data were modelled simultaneously by means of importance sampling in the non-linear mixed effects modelling software NONMEM. The infused endotoxin followed one-compartment disposition and non-linear elimination, and stimulated the production of TNF-alpha to describe the rapid increase in plasma concentration. Tolerance development, observed as declining TNF-alpha concentration with continued infusion of endotoxin, was also driven by endotoxin as a concentration-dependent increase in the potency parameter related to TNF-alpha production (EC50). Production of IL-6 was stimulated by both endotoxin and TNF-a, and four consecutive transit compartments described delayed increase in plasma IL-6. A model which simultaneously account for the time-courses of endotoxin and two immune response markers, the cytokines TNF-alpha and IL-6, as well as the development of endotoxin tolerance, was successfully established. This model-based approach is unique in its description of the time-courses and their interrelation and may be applied within research on immune response to bacterial endotoxin, or in pre-clinical pharmaceutical research when dealing with study design or translational aspects.

  • 177.
    Tovedal, Thomas
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Myrdal, Gunnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Thoraxkirurgi.
    Jonsson, Ove
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Bergquist, Maria
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Zemgulis, Vitas
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Thoraxkirurgi.
    Thelin, Stefan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Thoraxkirurgi.
    Lennmyr, Fredrik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård.
    Experimental treatment of superior venous congestion during cardiopulmonary bypass2013Ingår i: European Journal of Cardio-Thoracic Surgery, ISSN 1010-7940, E-ISSN 1873-734X, Vol. 44, nr 3, s. E239-E244Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVES:

    Superior venous outflow obstruction affects cerebral perfusion negatively by reducing cerebral perfusion pressure (CPP). We present a randomized study designed to compare two alternative strategies to preserve the CPP during superior vena cava (SVC) congestion and cardiopulmonary bypass (CPB).

    METHODS:

    Fourteen pigs on bi-caval CPB were subjected to 75% occlusion of the SVC flow. CPP was restored either by vasopressor treatment (VP, n = 7) or by partial relief (PR) of the congestion (n = 7). The cerebral effects of the interventions were studied for 60 min with intracranial pressure (ICP) monitoring, cerebral blood flow measurement, the near-infrared light spectroscopy tissue oxygen saturation index (StO2), arterial and venous blood gas analyses and serial measurements of the glial cell damage marker protein S100β.

    RESULTS:

    Both strategies restored the CPP to baseline levels and no signs of severe ischaemia were observed. In the PR group, the venous and ICPs were normalized in response to the intervention, while in the VP group those parameters remained elevated throughout the experiment. The haemoglobin oxygen saturation in the sagittal sinus (SsagO2) was increased by both VP and PR, while significant improvement in the StO2 was observed only in the PR group. The S100β concentrations were similar in the two groups.

    CONCLUSIONS:

    Experimental SVC obstruction during CPB may reduce the CPP, resulting in impaired cerebral perfusion. Both vasopressor treatment and improved venous drainage can, in the short term, individually restore the CPP during these circumstances.

  • 178.
    Tusman, Gerardo
    et al.
    Hosp Privado Comunidad Mar Del Plata, Mar Del Plata, Buenos Aires.
    Acosta, Cecilia
    Hosp Privado Comunidad Mar Del Plata, Mar Del Plata, Buenos Aires.
    Longo, Silvina
    Hosp Privado Cordoba, Dept Anaesthesia, Cordoba.
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. CIBERES, Madrid.
    Reply to: alveolar recruitment manoeuvres after cardiac surgery2018Ingår i: European Journal of Anaesthesiology, ISSN 0265-0215, E-ISSN 1365-2346, Vol. 35, nr 1, s. 62-63Artikel i tidskrift (Refereegranskat)
  • 179.
    Tusman, Gerardo
    et al.
    Hosp Privado Comunidad Mar Del Plata, Dept Anesthesiol, RA-7600 Mar Del Plata, Buenos Aires, Argentina..
    Acosta, Cecilia M.
    Hosp Privado Comunidad Mar Del Plata, Dept Anesthesiol, RA-7600 Mar Del Plata, Buenos Aires, Argentina..
    Boehm, Stephan H.
    Hepa Wash GmbH, Munich, Germany..
    Waldmann, Andreas D.
    Swisstom AG, Landquart, Switzerland..
    Ferrando, Carlos
    Univ Hosp Valencia, Dept Anesthesiol, Valencia, Spain..
    Perez Marquez, Manuel
    FJD, IIS, Dept Intens Care Med, Madrid, Spain..
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. CIBERES, Madrid, Spain; Department of Critical Care, Hospital La Fe, Valencia, Spain..
    Postural lung recruitment assessed by lung ultrasound in mechanically ventilated children2017Ingår i: Critical Ultrasound Journal, ISSN 2036-3176, E-ISSN 2036-7902, Vol. 9, artikel-id 22Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Atelectasis is a common finding in mechanically ventilated children with healthy lungs. This lung collapse cannot be overcome using standard levels of positive end-expiratory pressure (PEEP) and thus for only individualized lung recruitment maneuvers lead to satisfactory therapeutic results. In this short communication, we demonstrate by lung ultrasound images (LUS) the effect of a postural recruitment maneuver (P-RM, i.e., a ventilatory strategy aimed at reaerating atelectasis by changing body position under constant ventilation). Results: Data was collected in the operating room of the Hospital Privado de Comunidad, Mar del Plata, Argentina. Three anesthetized children undergoing mechanical ventilation at constant settings were sequentially subjected to the following two maneuvers: (1) PEEP trial in the supine position PEEP was increased to 10 cmH(2)O for 3 min and then decreased to back to baseline. (2) P-RM patient position was changed from supine to the left and then to the right lateral position for 90 s each before returning to supine. The total P-RM procedure took approximately 3 min. LUS in the supine position showed similar atelectasis before and after the PEEP trial. Contrarily, atelectasis disappeared in the non-dependent lung when patients were placed in the lateral positions. Both lungs remained atelectasis free even after returning to the supine position. Conclusions: We provide LUS images that illustrate the concept and effects of postural recruitment in children. This maneuver has the advantage of achieving recruitment effects without the need to elevate airways pressures.

  • 180.
    Tusman, Gerardo
    et al.
    Hosp Privado Comunidad Mar Del Plata, Dept Anesthesia, RA-4545 Cordoba, Argentina..
    Acosta, Cecilia M.
    Hosp Privado Comunidad Mar Del Plata, Dept Anesthesia, RA-4545 Cordoba, Argentina..
    Nicola, Marco
    Hosp Privado Comunidad Mar Del Plata, Dept Anesthesia, RA-4545 Cordoba, Argentina..
    Esperatti, Mariano
    Hosp Privado Comunidad Mar Del Plata, Intens Care Med, Buenos Aires, DF, Argentina..
    Bohm, Stephan H.
    Swisstom AG, Landquart, Switzerland..
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain..
    Real-time images of tidal recruitment using lung ultrasound2015Ingår i: Critical Ultrasound Journal, ISSN 2036-3176, E-ISSN 2036-7902, Vol. 7, artikel-id 19Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Ventilator-induced lung injury is a form of mechanical damage leading to a pulmonary inflammatory response related to the use of mechanical ventilation enhanced by the presence of atelectasis. One proposed mechanism of this injury is the repetitive opening and closing of collapsed alveoli and small airways within these atelectatic areas-a phenomenon called tidal recruitment. The presence of tidal recruitment is difficult to detect, even with high-resolution images of the lungs like CT scan. The purpose of this article is to give evidence of tidal recruitment by lung ultrasound. Findings: A standard lung ultrasound inspection detected lung zones of atelectasis in mechanically ventilated patients. With a linear probe placed in the intercostal oblique position. We observed tidal recruitment within atelectasis as an improvement in aeration at the end of inspiration followed by the re-collapse at the end of expiration. This mechanism disappeared after the performance of a lung recruitment maneuver. Conclusions: Lung ultrasound was helpful in detecting the presence of atelectasis and tidal recruitment and in confirming their resolution after a lung recruitment maneuver.

  • 181.
    Tusman, Gerardo
    et al.
    Hosp Privado Comunidad Mar Del Plata, Dept Anesthesiol, 7600 Mar Plata, Buenos Aires, DF, Argentina.
    Acosta, Cecilia M.
    Hosp Privado Comunidad Mar Del Plata, Dept Anesthesiol, 7600 Mar Plata, Buenos Aires, DF, Argentina.
    Pulletz, Sven
    Klinikum Osnabrueck, Dept Anesthesiol & Intens Care Med, Osnabruck, Germany.
    Boehm, Stephan H.
    Rostock Univ, Med Ctr, Dept Anesthesiol & Intens Care Med, Rostock, Germany.
    Scandurra, Adriana
    Mar Del Plata Univ, Sch Engn, Elect Dept, Bioengn Lab, Mar Del Plata, Buenos Aires, Argentina.
    Martinez Arca, Jorge
    Mar Del Plata Univ, Sch Engn, Elect Dept, Bioengn Lab, Mar Del Plata, Buenos Aires, Argentina.
    Madorno, Matias
    ITBA, Buenos Aires, DF, Argentina.
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. CIBERES, Madrid, Spain;Hosp Univ La Princesa, Dept Crit Care, Madrid, Spain.
    Photoplethysmographic characterization of vascular tone mediated changes in arterial pressure: an observational study2019Ingår i: Journal of clinical monitoring and computing, ISSN 1387-1307, E-ISSN 1573-2614, Vol. 33, nr 5, s. 815-824Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To determine whether a classification based on the contour of the photoplethysmography signal (PPGc) can detect changes in systolic arterial blood pressure (SAP) and vascular tone. Episodes of normotension (SAP 90-140 mmHg), hypertension (SAP > 140 mmHg) and hypotension (SAP < 90 mmHg) were analyzed in 15 cardiac surgery patients. SAP and two surrogates of the vascular tone, systemic vascular resistance (SVR) and vascular compliance (Cvasc = stroke volume/pulse pressure) were compared with PPGc. Changes in PPG amplitude (foot-to-peak distance) and dicrotic notch position were used to define 6 classes taking class III as a normal vascular tone with a notch placed between 20 and 50% of the PPG amplitude. Class I-to-II represented vasoconstriction with notch placed > 50% in a small PPG, while class IV-to-VI described vasodilation with a notch placed < 20% in a tall PPG wave. 190 datasets were analyzed including 61 episodes of hypertension [SAP = 159 (151-170) mmHg (median 1st-3rd quartiles)], 84 of normotension, SAP = 124 (113-131) mmHg and 45 of hypotension SAP = 85(80-87) mmHg. SAP were well correlated with SVR (r = 0.78, p < 0.0001) and Cvasc (r = 0.84, p < 0.0001). The PPG-based classification correlated well with SAP (r = - 0.90, p < 0.0001), SVR (r = - 0.72, p < 0.0001) and Cvasc (r = 0.82, p < 0.0001). The PPGc misclassified 7 out of the 190 episodes, presenting good accuracy (98.4% and 97.8%), sensitivity (100% and 94.9%) and specificity (97.9% and 99.2%) for detecting episodes of hypotension and hypertension, respectively. Changes in arterial pressure and vascular tone were closely related to the proposed classification based on PPG waveform. Clinical Trial Registration NTC02854852.

  • 182. Tusman, Gerardo
    et al.
    Boehm, Stephan H.
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Dead space during one-lung ventilation2015Ingår i: Current Opinion in Anaesthesiology, ISSN 0952-7907, E-ISSN 1473-6500, Vol. 28, nr 1, s. 10-17Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Purpose of review Describe the importance of monitoring dead space during thoracic surgery, specifically during one-lung ventilation. Recent findings The concept of dead space has gained renewed interest among anesthesiologists ever since breath-by-breath measurement by volumetric capnography became available. Monitoring dead space during thoracic surgery assesses the ventilatory deficiencies related to increases in instrumental, airway and/or alveolar dead space, when ventilating patients with positive pressure and double-lumen tubes. Another interesting use of such monitoring is to detect ventilator-induced lung injury due to tidal overdistension. This type of injury threatens the fragile lungs especially during one-lung ventilation and can clinically be recognized as an increase in airway and alveolar dead space above normal values. To date, lung protective ventilation is based on the use of low tidal volumes and airway pressures to decrease overdistension. It has been shown to reduce the incidence of postoperative pulmonary complications after thoracic surgeries. However, such a ventilatory strategy impairs ventilation and induces hypercapnia due to increases in dead space. Therefore, continuous assessment of dead space is helpful in guiding ventilation and avoiding overdistension while maintaining the elimination of CO2 during thoracic surgery sufficiently high. Summary Monitoring dead space helps anesthesiologists monitor the status of the lung and find appropriate ventilatory settings during thoracic surgeries.

  • 183.
    Tusman, Gerardo
    et al.
    Hosp Privado Comunidad Mar Del Plata, Dept Anesthesia, Cordoba 4545, RA-7600 Mar Del Plata, Buenos Aires, Argentina.
    Bohm, Stephan H.
    Swisstom AG, Landquart, Switzerland.
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Advanced Uses of Pulse Oximetry for Monitoring Mechanically Ventilated Patients2017Ingår i: Anesthesia and Analgesia, ISSN 0003-2999, E-ISSN 1526-7598, Vol. 124, nr 1, s. 62-71Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pulse oximetry is an undisputable standard of care in clinical monitoring. It combines a spectrometer to detect hypoxemia with a plethysmograph for the diagnosis, monitoring, and follow-up of cardiovascular diseases. These pulse oximetry capabilities are extremely useful for assessing the respiratory and circulatory status and for monitoring of mechanically ventilated patients. On the one hand, the key spectrography-derived function of pulse oximetry is to evaluate a patient's gas exchange that results from a particular ventilatory treatment by continuously and noninvasively measuring arterial hemoglobin saturation (Spo(2)). This information helps to maintain patients above the hypoxemic levels, leading to appropriate ventilator settings and inspired oxygen fractions. However, whenever higher than normal oxygen fractions are used, Spo(2) can mask existing oxygenation defects in ventilated patients. This limitation, resulting from the S shape of the oxyhemoglobin saturation curve, can be overcome by reducing the oxygen fraction delivered to the patient in a controlled and stepwise manner. This results in a Spo(2)/Fio(2) diagram, which allows a rough characterization of a patient's gas exchange, shunt, and the amount of lung area with a low ventilation/perfusion ratio without the need of blood sampling. On the other hand, the photoplethysmography-derived oximeter function has barely been exploited for the purpose of monitoring hemodynamics in mechanically ventilated patients. The analysis of the photoplethysmography contour provides useful real-time and noninvasive information about the interaction of heart and lungs during positive pressure ventilation. These hemodynamic monitoring capabilities are related to both the assessment of preload dependency mainly by analyzing the breath-by-breath variation of the photoplethysmographic signals and the analysis of arterial impedance, Which examines the changes in the plethysmographic amplitude, contour, and derived indexes. In this article, we present and describe these extended monitoring capabilities and propose a more holistic monitoring concept that takes advantage of these advanced uses of pulse oximetry in the monitoring of ventilated patients. Today's monitors need to be improved if such novel functionalities were to be offered for clinical use. Future developments and clinical evaluations are needed to establish the true potential of these advanced monitoring uses of pulse oximetry.

  • 184. Tusman, Gerardo
    et al.
    Gogniat, Emiliano
    Bohm, Stephan H.
    Scandurra, Adriana
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Torroba, Agustin
    Casella, Federico
    Giannasi, Sergio
    San Roman, Eduardo
    Reference values for volumetric capnography-derived non-invasive parameters in healthy individuals2013Ingår i: Journal of clinical monitoring and computing, ISSN 1387-1307, E-ISSN 1573-2614, Vol. 27, nr 3, s. 281-288Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to determine typical values for non-invasive volumetric capnography (VCap) parameters for healthy volunteers and anesthetized individuals. VCap was obtained by a capnograph connected to the airway opening. We prospectively studied 33 healthy volunteers 32 +/- A 6 years of age weighing 70 +/- A 13 kg at a height of 171 +/- A 11 cm in the supine position. Data from these volunteers were compared with a cohort of similar healthy anesthetized patients ventilated with the following settings: tidal volume (VT) of 6-8 mL/kg, respiratory rate 10-15 bpm, PEEP of 5-6 cmH(2)O and FiO(2) of 0.5. Volunteers showed better clearance of CO2 compared to anesthetized patients as indicated by (median and interquartile range): (1) an increased elimination of CO2 per mL of VT of 0.028 (0.005) in volunteers versus 0.023 (0.003) in anesthetized patients, p < 0.05; (2) a lower normalized slope of phase III of 0.26 (0.17) in volunteers versus 0.39 (0.38) in anesthetized patients, p < 0.05; and (3) a lower Bohr dead space ratio of 0.23 (0.05) in volunteers versus 0.28 (0.05) in anesthetized patients, p < 0.05. This study presents reference values for non-invasive volumetric capnography-derived parameters in healthy individuals. Mechanical ventilation and anesthesia altered these values significantly.

  • 185. Tusman, Gerardo
    et al.
    Groisman, Ivan
    Fiolo, Felipe E.
    Scandurra, Adriana
    Martinez Arca, Jorge
    Krumrick, Gustavo
    Bohm, Stephan H.
    Suarez Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Noninvasive Monitoring of Lung Recruitment Maneuvers in Morbidly Obese Patients: The Role of Pulse Oximetry and Volumetric Capnography2014Ingår i: Anesthesia and Analgesia, ISSN 0003-2999, E-ISSN 1526-7598, Vol. 118, nr 1, s. 137-144Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: We conducted this study to determine whether pulse oximetry and volumetric capnography (VCap) can determine the opening and closing pressures of lungs of anesthetized morbidly obese patients. METHODS: Twenty morbidly obese patients undergoing laparoscopic bariatric surgery with capnoperitoneum were studied. A lung recruitment maneuver was performed in pressure control ventilation as follows: (1) During an ascending limb, the lungs' opening pressure was detected. After increasing positive end-expiratory pressure (PEEP) from 8 to 16 cm H2O, fraction of inspired oxygen (Fio(2)) was decreased until pulse oximetric arterial saturation (Spo(2)) was <92%. Thereafter, end-inspiratory pressure was increased in steps of 2 cm H2O, from 36 to a maximum of 50 cm H2O. The opening pressure was attained when Spo(2) exceeded 97%. (2) During a subsequent decreasing limb, the lungs' closing pressure was identified. PEEP was decreased from 22 to 10 cm H2O in steps of 2 cm H2O. The closing pressure was determined as the PEEP value at which respiratory compliance decreased from its maximum value. We continuously recorded lung mechanics, Spo(2), and VCap. RESULTS: The lungs' opening pressures were detected at 44 (4) cm H2O (median and interquartile range) and the closing pressure at 14 (2) cm H2O. Therefore, the level of PEEP that kept the lungs without collapse was found to be 16 (3) cm H2O. Using respiratory compliance as a reference, receiver operating characteristic analysis showed that Spo(2) (area under the curve [AUC] 0.80 [SE 0.07], sensitivity 0.65, and specificity 0.94), the elimination of CO2 per breath (AUC 0.91 [SE 0.05], sensitivity 0.85, and specificity 0.98), and Bohr's dead space (AUC 0.83 [SE 0.06], sensitivity 0.70, and specificity 0.95] were relatively accurate for detecting lung collapse during the decreasing limb of a recruitment maneuver. CONCLUSIONS: Lung recruitment in morbidly obese patients could be effectively monitored by combining noninvasive pulse oximetry and VCap. Spo(2), the elimination of CO2, and Bohr's dead space detected the individual's opening and closing pressures.

  • 186.
    Tusman, Gerardo
    et al.
    Hosp Privado Comunidad Mar Del Plata, Dept Anesthesia, Mar Del Plata, Buenos Aires, Argentina..
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Confusion Between Integration and Receiver Operator Curves?: Response2016Ingår i: Anesthesia and Analgesia, ISSN 0003-2999, E-ISSN 1526-7598, Vol. 123, nr 5, s. 1332-1333Artikel i tidskrift (Refereegranskat)
  • 187.
    Velikyan, Irina
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för nuklearmedicin och PET.
    Sörensen, Jens
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för nuklearmedicin och PET.
    Retamal, Jaime
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Jalkanen, S.
    Univ Turku, MediC Res Lab, Turku, Finland.;Univ Turku, Dept Med Microbiol & Immunol, Turku, Finland..
    Antoni, Gunnar
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi.
    Hedenstierna, Göran
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Klinisk fysiologi.
    Roivainen, A.
    Univ Turku, Turku PET Ctr, Turku, Finland..
    Larsson, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet.
    Lubberink, Mark
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för radiologi, onkologi och strålningsvetenskap, Enheten för nuklearmedicin och PET.
    Dynamic scanning, kinetic modelling and parametric images reveal lung inflammation2016Ingår i: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 43, s. S157-S157Artikel i tidskrift (Refereegranskat)
  • 188.
    Villar, Jesus
    et al.
    Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain.;Hosp Univ Dr Negrin, Res Unit, Multidisciplinary Organ Dysfunct Evaluat Res Netw, Las Palmas Gran Canaria, Spain..
    Blanco, Jesus
    Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain.;Hosp Univ Rio Hortega, Intens Care Unit, Valladolid, Spain..
    del Campo, Rafael
    Hosp Gen Ciudad Real, Intens Care Unit, Ciudad Real, Spain..
    Andaluz-Ojeda, David
    Univ Valladolid, Hosp Clin, Intens Care Unit, Valladolid, Spain..
    Diaz-Dominguez, Francisco J.
    Hosp Univ Gen Leon, Intens Care Unit, Leon, Spain..
    Muriel, Arturo
    Hosp Univ Rio Hortega, Intens Care Unit, Valladolid, Spain..
    Corcoles, Virgilio
    Complejo Hosp Univ Albacete, Intens Care Unit, Albacete, Spain..
    Suarez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain..
    Tarancon, Concepcion
    Hosp Virgen de la Concha, Intens Care Unit, Zamora, Spain..
    Gonzalez-Higueras, Elena
    Hosp Virgen de la Luz, Intens Care Unit, Cuenca, Spain..
    Lopez, Julia
    Hosp Univ La Paz, Intens Care Unit, Madrid, Spain..
    Blanch, Lluis
    Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain.;Corp Sanitaria Parc Tauli, Crit Care Ctr, Sabadell, Spain..
    Perez-Mendez, Lina
    Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain.;Hosp Univ NS Candelaria, Res Unit, Tenerife, Spain..
    Fernandez, Rosa Lidia
    Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain.;Hosp Univ Dr Negrin, Res Unit, Multidisciplinary Organ Dysfunct Evaluat Res Netw, Las Palmas Gran Canaria, Spain..
    Kacmarek, Robert M.
    Massachusetts Gen Hosp, Dept Resp Care, Boston, MA 02114 USA.;Harvard Univ, Dept Anesthesiol, Boston, MA 02115 USA..
    Assessment of PaO2/FiO(2) for stratification of patients with moderate and severe acute respiratory distress syndrome2015Ingår i: BMJ Open, ISSN 2044-6055, E-ISSN 2044-6055, Vol. 5, nr 3, artikel-id e006812Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objectives: A recent update of the definition of acute respiratory distress syndrome (ARDS) proposed an empirical classification based on ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO(2)) at ARDS onset. Since the proposal did not mandate PaO2/FiO(2) calculation under standardised ventilator settings (SVS), we hypothesised that a stratification based on baseline PaO2/FiO(2) would not provide accurate assessment of lung injury severity. Design: A prospective, multicentre, observational study. Setting: A network of teaching hospitals. Participants: 478 patients with eligible criteria for moderate (100<PaO2/FiO(2)<= 200) and severe (PaO2/FiO(2)<= 100) ARDS and followed until hospital discharge. Interventions: We examined physiological and ventilator parameters in association with the PaO2/FiO(2) at ARDS onset, after 24 h of usual care and at 24 h under a SVS. At 24 h, patients were reclassified as severe, moderate, mild (200<PaO2/FiO(2)<= 300) ARDS and non-ARDS (PaO2/FiO(2)>300). Primary and secondary outcomes: Group severity and hospital mortality. Results: At ARDS onset, 173 patients had a PaO2/FiO(2)<= 100 but only 38.7% met criteria for severe ARDS at 24 h under SVS. When assessed under SVS, 61.3% of patients with severe ARDS were reclassified as moderate, mild and non-ARDS, while lung severity and hospital mortality changed markedly with every PaO2/FiO(2) category (p<0.000001). Our model of risk stratification outperformed the stratification using baseline PaO2/FiO(2) and non-standardised PaO2/FiO(2) at 24 h, when analysed by the predictive receiver operating characteristic (ROC) curve: area under the ROC curve for stratification at baseline was 0.583 (95% CI 0.525 to 0.636), 0.605 (95% CI 0.552 to 0.658) at 24 h without SVS and 0.693 (95% CI 0.645 to 0.742) at 24 h under SVS (p<0.000001). Conclusions: Our findings support the need for patient assessment under SVS at 24 h after ARDS onset to assess disease severity, and have implications for the diagnosis and management of ARDS patients.

  • 189.
    Villar, Jesus
    et al.
    Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain.;Hosp Univ Dr Negrin, Res Unit, Las Palmas Gran Canaria, Spain..
    Martin-Rodriguez, Carmen
    Hosp Gen Ciudad Real, Intens Care Unit, Ciudad Real, Spain..
    Dominguez-Berrot, Ana M.
    Complejo Asistencial Univ Leon, Intens Care Unit, Leon, Spain..
    Fernandez, Lorena
    Hosp Univ Rio Hortega, Intens Care Unit, Valladolid, Spain..
    Ferrando, Carlos
    Hosp Clin Univ, Dept Anesthesiol, Valencia, Spain..
    Soler, Juan A.
    Hosp Univ Morales Meseguer, Intens Care Unit, Murcia, Spain..
    Diaz-Lamas, Ana M.
    Hosp Univ A Coruna, Intens Care Unit, Coruna, Spain..
    Gonzalez-Higueras, Elena
    Hosp Virgen de La Luz, Intens Care Unit, Cuenca, Spain..
    Nogales, Leonor
    Hosp Clin Univ, Intens Care Unit, Valladolid, Spain..
    Ambros, Alfonso
    Hosp Gen Ciudad Real, Intens Care Unit, Ciudad Real, Spain..
    Carriedo, Demetrio
    Complejo Asistencial Univ Leon, Intens Care Unit, Leon, Spain..
    Hernandez, Monica
    Hosp Univ La Paz, Intens Care Unit, Madrid, Spain..
    Martinez, Domingo
    Hosp Univ Virgen de Arrixaca, Intens Care Unit, Murcia, Spain..
    Blanco, Jesus
    Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain.;Hosp Univ Rio Hortega, Intens Care Unit, Valladolid, Spain..
    Belda, Javier
    Hosp Clin Univ, Dept Anesthesiol, Valencia, Spain..
    Parrilla, Dacil
    Hosp Univ NS Candelaria, Intens Care Unit, Santa Cruz De Tenerife, Spain..
    Suárez-Sipmann, Fernando
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Anestesiologi och intensivvård. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Hedenstiernalaboratoriet. Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain..
    Tarancon, Concepcion
    Hosp Virgen de la Concha, Intens Care Unit, Zamora, Spain..
    Mora-Ordonez, Juan M.
    Hosp Univ Carlos Haya, Intens Care Unit, Malaga, Spain..
    Blanch, Lluis
    Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain.;Corp Sanitaria Parc Tauli, Crit Care Ctr, Sabadell, Spain..
    Perez-Mendez, Lina
    Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain.;Hosp Univ NS Candelaria, Res Unit, Santa Cruz De Tenerife, Spain..
    Fernandez, Rosa L.
    Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain.;Hosp Univ Dr Negrin, Res Unit, Las Palmas Gran Canaria, Spain..