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Suarez-Sipmann, FernandoORCID iD iconorcid.org/0000-0002-7412-2970
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Publications (10 of 61) Show all publications
Ferrando, C., Aldecoa, C., Unzueta, C., Javier Belda, F., Librero, J., Tusman, G., . . . Visiedo, S. (2020). Effects of oxygen on post-surgical infections during an individualised perioperative open-lung ventilatory strategy: a randomised controlled trial. British Journal of Anaesthesia, 124(1), 110-120
Open this publication in new window or tab >>Effects of oxygen on post-surgical infections during an individualised perioperative open-lung ventilatory strategy: a randomised controlled trial
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2020 (English)In: British Journal of Anaesthesia, ISSN 0007-0912, E-ISSN 1471-6771, Vol. 124, no 1, p. 110-120Article in journal (Refereed) Published
Abstract [en]

Background: We aimed to examine whether using a high fraction of inspired oxygen (FIO2) in the context of an individualised intra- and postoperative open-lung ventilation approach could decrease surgical site infection (SSI) in patients scheduled for abdominal surgery. Methods: We performed a multicentre, randomised controlled clinical trial in a network of 21 university hospitals from June 6, 2017 to July 19, 2018. Patients undergoing abdominal surgery were randomly assigned to receive a high (0.80) or conventional (0.3) FIO2 during the intraoperative period and during the first 3 postoperative hours. All patients were mechanically ventilated with an open-lung strategy, which included recruitment manoeuvres and individualised positive end-expiratory pressure for the best respiratory-system compliance, and individualised continuous postoperative airway pressure for adequate peripheral oxyhaemoglobin saturation. The primary outcome was the prevalence of SSI within the first 7 postoperative days. The secondary outcomes were composites of systemic complications, length of intensive care and hospital stay, and 6-month mortality. Results: We enrolled 740 subjects: 371 in the high FIO2 group and 369 in the low FIO2 group. Data from 717 subjects were available for final analysis. The rate of SSI during the first postoperative week did not differ between high (8.9%) and low (9.4%) FIO2 groups (relative risk [RR]: 0.94; 95% confidence interval [CI]: 0.59-1.50; P=0.90]). Secondary outcomes, such as atelectasis (7.7% vs 9.8%; RR: 0.77; 95% CI: 0.48-1.25; P=0.38) and myocardial ischaemia (0.6% [n=2] vs 0% [n=0]; P=0.47) did not differ between groups. Conclusions: An oxygenation strategy using high FIO2 compared with conventional FIO2 did not reduce postoperative SSIs in abdominal surgery. No differences in secondary outcomes or adverse events were found.

Place, publisher, year, edition, pages
ELSEVIER SCI LTD, 2020
Keywords
anaesthesia, inspiratory oxygen fraction, positive end-expiratory pressure, postoperative complications, recruitment manoeuvres, sepsis, surgery, surgical site infection
National Category
Anesthesiology and Intensive Care
Identifiers
urn:nbn:se:uu:diva-401176 (URN)10.1016/j.bja.2019.10.009 (DOI)000503385700025 ()31767144 (PubMedID)
Available from: 2020-01-07 Created: 2020-01-07 Last updated: 2020-01-07Bibliographically approved
Heili-Frades, S., Suarez-Sipmann, F., Santos, A., Pilar Carballosa, M., Naya-Prieto, A., Castilla-Reparaz, C., . . . Peces-Barba, G. (2019). Continuous monitoring of intrinsic PEEP based on expired CO2 kinetics: an experimental validation study. Critical Care, 23, Article ID 192.
Open this publication in new window or tab >>Continuous monitoring of intrinsic PEEP based on expired CO2 kinetics: an experimental validation study
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2019 (English)In: Critical Care, ISSN 1364-8535, E-ISSN 1466-609X, Vol. 23, article id 192Article in journal (Refereed) Published
Abstract [en]

Background Quantification of intrinsic PEEP (PEEPi) has important implications for patients subjected to invasive mechanical ventilation. A new non-invasive breath-by-breath method (etCO(2)D) for determination of PEEPi is evaluated. MethodsIn 12 mechanically ventilated pigs, dynamic hyperinflation was induced by interposing a resistance in the endotracheal tube. Airway pressure, flow, and exhaled CO2 were measured at the airway opening. Combining different I:E ratios, respiratory rates, and tidal volumes, 52 different levels of PEEPi (range 1.8-11.7cmH(2)O; mean 8.450.32cmH(2)O) were studied. The etCO(2)D is based on the detection of the end-tidal dilution of the capnogram. This is measured at the airway opening by means of a CO2 sensor in which a 2-mm leak is added to the sensing chamber. This allows to detect a capnogram dilution with fresh air when the pressure coming from the ventilator exceeds the PEEPi. This method was compared with the occlusion method. Results The etCO(2)D method detected PEEPi step changes of 0.2cmH(2)O. Reference and etCO(2)D PEEPi presented a good correlation (R-2 0.80, P<0.0001) and good agreement, bias -0.26, and limits of agreement +/- 1.96 SD (2.23, -2.74) (P<0.0001). Conclusions The etCO(2)D method is a promising accurate simple way of continuously measure and monitor PEEPi. Its clinical validity needs, however, to be confirmed in clinical studies and in conditions with heterogeneous lung diseases.

Place, publisher, year, edition, pages
BMC, 2019
Keywords
Intrinsic PEEP, Dynamic hyperinflation, CO2, Volumetric capnography, Mechanical ventilation
National Category
Anesthesiology and Intensive Care
Identifiers
urn:nbn:se:uu:diva-386446 (URN)10.1186/s13054-019-2430-9 (DOI)000469485400001 ()31142337 (PubMedID)
Funder
EU, European Research Council, 796721
Available from: 2019-06-26 Created: 2019-06-26 Last updated: 2019-06-26Bibliographically approved
Suarez-Sipmann, F., Ferrando, C. & Villar, J. (2019). PEEP titration guided by transpulmonary pressure: lessons from a negative trial. Journal of Thoracic Disease, 11, S1957-S1962
Open this publication in new window or tab >>PEEP titration guided by transpulmonary pressure: lessons from a negative trial
2019 (English)In: Journal of Thoracic Disease, ISSN 2072-1439, E-ISSN 2077-6624, Vol. 11, p. S1957-S1962Article in journal, Editorial material (Other academic) Published
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.

National Category
Respiratory Medicine and Allergy
Identifiers
urn:nbn:se:uu:diva-395998 (URN)10.21037/jtd.2019.08.03 (DOI)000488235600037 ()31632797 (PubMedID)
Available from: 2019-10-28 Created: 2019-10-28 Last updated: 2019-10-28Bibliographically approved
Tusman, G., Acosta, C. M., Pulletz, S., Boehm, S. H., Scandurra, A., Martinez Arca, J., . . . Suarez-Sipmann, F. (2019). Photoplethysmographic characterization of vascular tone mediated changes in arterial pressure: an observational study. Journal of clinical monitoring and computing, 33(5), 815-824
Open this publication in new window or tab >>Photoplethysmographic characterization of vascular tone mediated changes in arterial pressure: an observational study
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2019 (English)In: Journal of clinical monitoring and computing, ISSN 1387-1307, E-ISSN 1573-2614, Vol. 33, no 5, p. 815-824Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
SPRINGER HEIDELBERG, 2019
Keywords
Arterial pressure, Photoplethysmography, Vasodilation, Vasoconstriction, Vascular tone
National Category
Cardiac and Cardiovascular Systems
Identifiers
urn:nbn:se:uu:diva-394047 (URN)10.1007/s10877-018-0235-z (DOI)000482910800010 ()30554338 (PubMedID)
Available from: 2019-10-04 Created: 2019-10-04 Last updated: 2019-10-04Bibliographically approved
Suarez-Sipmann, F. & Blanch, L. (2019). Physiological Markers for Acute Respiratory Distress Syndrome: Let's Get More Efficient!. American Journal of Respiratory and Critical Care Medicine, 199(3), 260-261
Open this publication in new window or tab >>Physiological Markers for Acute Respiratory Distress Syndrome: Let's Get More Efficient!
2019 (English)In: American Journal of Respiratory and Critical Care Medicine, ISSN 1073-449X, E-ISSN 1535-4970, Vol. 199, no 3, p. 260-261Article in journal, Editorial material (Other academic) Published
Place, publisher, year, edition, pages
AMER THORACIC SOC, 2019
National Category
Respiratory Medicine and Allergy
Identifiers
urn:nbn:se:uu:diva-377494 (URN)10.1164/rccm.201809-1653ED (DOI)000457414800006 ()30240279 (PubMedID)
Available from: 2019-02-22 Created: 2019-02-22 Last updated: 2019-02-22Bibliographically approved
Carraminana, A., Ferrando, C., Unzueta, M. C., Navarro, R., Suarez-Sipmann, F., Tusman, G., . . . Espinosa, E. (2019). Rationale and Study Design for an Individualized Perioperative Open Lung Ventilatory Strategy in Patients on One-Lung Ventilation (iPROVE-OLV). Journal of Cardiothoracic and Vascular Anesthesia, 33(9), 2492-2502
Open this publication in new window or tab >>Rationale and Study Design for an Individualized Perioperative Open Lung Ventilatory Strategy in Patients on One-Lung Ventilation (iPROVE-OLV)
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2019 (English)In: Journal of Cardiothoracic and Vascular Anesthesia, ISSN 1053-0770, E-ISSN 1532-8422, Vol. 33, no 9, p. 2492-2502Article in journal (Refereed) Published
Abstract [en]

Objective: The aim of this clinical trial is to examine whether it is possible to reduce postoperative complications using an individualized perioperative ventilatory strategy versus using a standard lung-protective ventilation strategy in patients scheduled for thoracic surgery requiring one-lung ventilation. Design: International, multicenter, prospective, randomized controlled clinical trial. Setting: A network of university hospitals. Participants: The study comprises 1,380 patients scheduled for thoracic surgery. Interventions: The individualized group will receive intraoperative recruitment maneuvers followed by individualized positive end-expiratory pressure (open lung approach) during the intraoperative period plus postoperative ventilatory support with high-flow nasal cannula, whereas the control group will be managed with conventional lung-protective ventilation. Measurements and Main Results: Individual and total number of postoperative complications, including atelectasis, pneumothorax, pleural effusion, pneumonia, acute lung injury; unplanned readmission and reintubation; length of stay and death in the critical care unit and in the hospital will be analyzed for both groups. The authors hypothesize that the intraoperative application of an open lung approach followed by an individual indication of high-flow nasal cannula in the postoperative period will reduce pulmonary complications and length of hospital stay in high-risk surgical patients. (C) 2019 Published by Elsevier Inc.

Place, publisher, year, edition, pages
W B SAUNDERS CO-ELSEVIER INC, 2019
Keywords
mechanical ventilation, postoperative pulmonary complications, one-lung ventilation, positive end-expiratory pressure, recruitment maneuvers
National Category
Anesthesiology and Intensive Care
Identifiers
urn:nbn:se:uu:diva-394056 (URN)10.1053/j.jvca.2019.01.056 (DOI)000483007700024 ()30928294 (PubMedID)
Available from: 2019-10-03 Created: 2019-10-03 Last updated: 2019-10-03Bibliographically approved
Gogniat, E., Ducrey, M., Dianti, J., Madorno, M., Roux, N., Midley, A., . . . Tusman, G. (2018). Dead space analysis at different levels of positive end-expiratory pressure in acute respiratory distress syndrome patients. Paper presented at National Meeting of Intensive Care Medicine, OCT, 2015, Mar del Plata, ARGENTINA. Journal of critical care, 45, 231-238
Open this publication in new window or tab >>Dead space analysis at different levels of positive end-expiratory pressure in acute respiratory distress syndrome patients
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2018 (English)In: Journal of critical care, ISSN 0883-9441, E-ISSN 1557-8615, Vol. 45, p. 231-238Article in journal (Refereed) Published
Abstract [en]

Purpose: To analyze the effects of positive end-expiratory pressure (PEEP) on Bohr's dead space (VDBohr/VT) in patients with acute respiratory distress syndrome (ARDS).

Material and methods: Fourteen ARDS patients under lung protective ventilation settingswere submitted to 4 different levels of PEEP (0, 6, 10, 16 cmH(2)O). Respiratory mechanics, hemodynamics and volumetric capnography were recorded at each protocol step.

Results: Two groups of patients responded differently to PEEP when comparing baseline with 16-PEEP: those in which driving pressure increased > 15% (Delta P.(15%), n = 7, p = .016) and those in which the change was <= 15% (Delta P-<= 15%, n = 7, p = .700). VDBohr/VT was higher in Delta P-<= 15% than in Delta P-<= 15% patients at baseline ventilation [0.58 (0.49-0.60) vs 0.46 (0.43-0.46) p = .018], at 0-PEEP [0.50 (0.47-0.54) vs 0.41 (0.40-0.43) p = .012], at 6-PEEP [0.55 (0.49-0.57) vs 0.44 (0.42-0.45) p = .008], at 10-PEEP [0.59 (0.51-0.59) vs 0.45 (0.44-0.46) p = .006] and at 16-PEEP [0.61 (0.56-0.65) vs 0.47 (0.45-0.48) p =. 001]. We found a good correlation between Delta P and VDBohr/VT only in the Delta P.(15%) group (r = 0.74, p < .001).

Conclusions: Increases in PEEP result in higher VDBohr/VT only when associated with an increase in driving pressure.

Place, publisher, year, edition, pages
W B SAUNDERS CO-ELSEVIER INC, 2018
Keywords
ARDS, Volumetric capnography, PEEP, PACO(2), Dead space, Carbon dioxide
National Category
Anesthesiology and Intensive Care
Identifiers
urn:nbn:se:uu:diva-356615 (URN)10.1016/j.jcrc.2018.01.005 (DOI)000432695500037 ()29754942 (PubMedID)
Conference
National Meeting of Intensive Care Medicine, OCT, 2015, Mar del Plata, ARGENTINA
Available from: 2018-08-20 Created: 2018-08-20 Last updated: 2018-08-20Bibliographically approved
Suarez Sipmann, F., Santos, A. & Tusman, G. (2018). Heart-lung interactions in acute respiratory distress syndrome: pathophysiology, detection and management strategies. Annals of Translational Medicine, 6(2), Article ID 27.
Open this publication in new window or tab >>Heart-lung interactions in acute respiratory distress syndrome: pathophysiology, detection and management strategies
2018 (English)In: Annals of Translational Medicine, ISSN 2305-5839, E-ISSN 2305-5847, Vol. 6, no 2, article id 27Article, review/survey (Refereed) Published
Abstract [en]

Acute respiratory distress syndrome (ARDS) is the most severe form of acute respiratory failure characterized by diffuse alveolar and endothelial damage. The severe pathophysiological changes in lung parenchyma and pulmonary circulation together with the effects of positive pressure ventilation profoundly affect heart lung interactions in ARDS. The term pulmonary vascular dysfunction (PVD) refers to the specific involvement of the vascular compartment in ARDS and is expressed clinically by an increase in pulmonary arterial (PA) pressure and pulmonary vascular resistance both affecting right ventricular (RV) afterload. When severe, PVD can lead to RV failure which is associated to an increased mortality. The effect of PVD on RV function is not only a consequence of increased pulmonary vascular resistance as afterload is a much more complex phenomenon that includes all factors that oppose efficient ventricular ejection. Impaired pulmonary vascular mechanics including increased arterial elastance and augmented wave-reflection phenomena are commonly seen in ARDS and can additionally affect RV afterload. The use of selective pulmonary vasodilators and lung protective mechanical ventilation strategies are therapeutic interventions that can ameliorate PVD. Prone positioning and the open lung approach (OLA) are especially attractive strategies to improve PVD due to their effects on increasing functional lung volume. In this review we will describe some pathophysiological aspects of heart-lung interactions during the ventilatory support of ARDS, its clinical assessment and discuss therapeutic interventions to prevent the occurrence and progression of PVD and RV failure.

Place, publisher, year, edition, pages
AME PUBL CO, 2018
Keywords
Acute respiratory distress syndrome (ARDS), pulmonary vascular dysfunction (PVD), pulmonary vascular resistance (PVR), lung protective ventilation, positive end-expiratory pressure (PEEP), pulmonary vascular mechanics, prone positioning, open lung approach (OLA)
National Category
Respiratory Medicine and Allergy
Identifiers
urn:nbn:se:uu:diva-350116 (URN)10.21037/atm.2017.12.07 (DOI)000423443000007 ()29430444 (PubMedID)
Available from: 2018-05-07 Created: 2018-05-07 Last updated: 2018-05-07Bibliographically approved
Ferrando, C., Soro, M., Unzueta, C., Suarez-Sipmann, F., Canet, J., Librero, J., . . . Belda, J. (2018). Individualised perioperative open-lung approach versus standard protective ventilation in abdominal surgery (iPROVE): a randomised controlled trial. The Lancet Respiratory Medicine, 6(3), 193-203
Open this publication in new window or tab >>Individualised perioperative open-lung approach versus standard protective ventilation in abdominal surgery (iPROVE): a randomised controlled trial
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2018 (English)In: The Lancet Respiratory Medicine, ISSN 2213-2600, E-ISSN 2213-2619, Vol. 6, no 3, p. 193-203Article in journal (Refereed) Published
Abstract [en]

Background The effects of individualised perioperative lung-protective ventilation (based on the open-lung approach [OLA]) on postoperative complications is unknown. We aimed to investigate the effects of intraoperative and postoperative ventilatory management in patients scheduled for abdominal surgery, compared with standard protective ventilation. Methods We did this prospective, multicentre, randomised controlled trial in 21 teaching hospitals in Spain. We enrolled patients who were aged 18 years or older, were scheduled to have abdominal surgery with an expected time of longer than 2 h, had intermediate-to-high-risk of developing postoperative pulmonary complications, and who had a body-mass index less than 35 kg/m(2). Patients were randomly assigned (1: 1: 1: 1) online to receive one of four lung-protective ventilation strategies using low tidal volume plus positive end-expiratory pressure (PEEP): open-lung approach (OLA)-iCPAP (individualised intraoperative ventilation [individualised PEEP after a lung recruitment manoeuvre] plus individualised postoperative continuous positive airway pressure [CPAP]), OLA-CPAP (intraoperative individualised ventilation plus postoperative CPAP), STD-CPAP (standard intraoperative ventilation plus postoperative CPAP), or STD-O-2 (standard intraoperative ventilation plus standard postoperative oxygen therapy). Patients were masked to treatment allocation. Investigators were not masked in the operating and postoperative rooms; after 24 h, data were given to a second investigator who was masked to allocations. The primary outcome was a composite of pulmonary and systemic complications during the first 7 postoperative days. We did the primary analysis using the modified intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT02158923. Findings Between Jan 2, 2015, and May 18, 2016, we enrolled 1012 eligible patients. Data were available for 967 patients, whom we included in the final analysis. Risk of pulmonary and systemic complications did not differ for patients in OLA-iCPAP (110 [46%] of 241, relative risk 0.89 [95% CI 0.74-1.07; p=0.25]), OLA-CPAP (111 [47%] of 238, 0.91 [0.76-1.09; p=0.35]), or STD-CPAP groups (118 [48%] of 244, 0.95 [0.80-1.14; p=0.65]) when compared with patients in the STD-O-2 group (125 [51%] of 244). Intraoperatively, PEEP was increased in 69 (14%) of patients in the standard perioperative ventilation groups because of hypoxaemia, and no patients from either of the OLA groups required rescue manoeuvres. Interpretation In patients who have major abdominal surgery, the different perioperative open lung approaches tested in this study did not reduce the risk of postoperative complications when compared with standard lung-protective mechanical ventilation.

Place, publisher, year, edition, pages
ELSEVIER SCI LTD, 2018
National Category
Anesthesiology and Intensive Care Respiratory Medicine and Allergy
Identifiers
urn:nbn:se:uu:diva-350497 (URN)10.1016/S2213-2600(18)30024-9 (DOI)000426242800020 ()29371130 (PubMedID)
Available from: 2018-05-09 Created: 2018-05-09 Last updated: 2018-05-09Bibliographically approved
Sigmundsson, T. S., Öhman, T., Hallbäck, M., Redondo, E., Suarez-Sipmann, F., Wallin, M., . . . Björne, H. (2018). Performance of a capnodynamic method estimating effective pulmonary blood flow during transient and sustained hypercapnia. Journal of clinical monitoring and computing, 32(2), 311-319
Open this publication in new window or tab >>Performance of a capnodynamic method estimating effective pulmonary blood flow during transient and sustained hypercapnia
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2018 (English)In: Journal of clinical monitoring and computing, ISSN 1387-1307, E-ISSN 1573-2614, Vol. 32, no 2, p. 311-319Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
SPRINGER HEIDELBERG, 2018
Keywords
Carbon dioxide, Cardiac output, Intraoperative monitoring, Effective pulmonary blood flow, Capnodynamic, Animal model
National Category
Anesthesiology and Intensive Care
Identifiers
urn:nbn:se:uu:diva-350733 (URN)10.1007/s10877-017-0021-3 (DOI)000426788500016 ()28497180 (PubMedID)
Funder
Stockholm County Council, 20140430, 20150910
Available from: 2018-05-16 Created: 2018-05-16 Last updated: 2018-05-16Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7412-2970

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