uu.seUppsala University Publications
Change search
Refine search result
1 - 12 of 12
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Covaciu, Lucian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Intranasal Cooling for Cerebral Hypothermia Treatment2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The controlled lowering of core body temperature to 32°C to 34°C is defined as therapeutic hypothermia (TH). Therapeutic hypothermia has been shown to improve neurological outcome and survival in unconscious patients successfully resuscitated after cardiac arrest. Brain temperature is important for cerebral protection therefore methods for primarily cooling the brain have also been explored.

    This thesis focuses on the likelihood that intranasal cooling can induce, maintain and control cerebral hypothermia. The method uses bilaterally introduced intranasal balloons circulated with cold saline.

    Selective brain cooling induced with this method was effectively accomplished in pigs with normal circulation while no major disturbances in systemic circulation or physiological variables were recorded. The temperature gradients between brain and body could be maintained for at least six hours.

    Intranasal balloon catheters were used for therapeutic hypothermia initiation and maintenance during and after successful resuscitation in pigs. Temperature reduction was also obtained by combined intranasal cooling and intravenous ice-cold fluids with possible additional benefits in terms of physiologic stability after cardiac arrest. Rewarming was possible via the intranasal balloons.

    In these studies brain temperature was recorded invasively by temperature probes inserted in the brain. The fast changes in pig’s brain temperature could also be tracked by a non-invasive method. High-spatial resolution magnetic resonance spectroscopic imaging (MRSI) without internal reference showed a good association with direct invasive temperature monitoring. In addition the mapping of temperature changes during brain cooling was also possible.

    In awake and unsedated volunteers subjected to intranasal cooling brain temperature changes were followed by two MR techniques. Brain cooling was shown by the previously calibrated high-spatial resolution MRSI and by the phase-mapping method. Intranasal cooling reduced body temperature slightly. The volunteers remained alert during cooling, the physiological parameters stable, and no shivering was reported.

    List of papers
    1. Intranasal selective brain cooling in pigs
    Open this publication in new window or tab >>Intranasal selective brain cooling in pigs
    Show others...
    2008 (English)In: Resuscitation, ISSN 0300-9572, E-ISSN 1873-1570, Vol. 78, no 1, p. 83-88Article in journal (Refereed) Published
    Abstract [en]

    BACKGROUND: Special clinical situations where general hypothermia cannot be recommended but can be a useful treatment demand a new approach, selective brain cooling. The purpose of this study was to selectively cool the brain with cold saline circulating in balloon catheters introduced into the nasal cavity in pigs. MATERIAL AND METHODS: Twelve anaesthetised pigs were subjected to selective cerebral cooling for a period of 6 h. Cerebral temperature was lowered by means of bilaterally introduced nasal balloon catheters perfused with saline cooled by a heat exchanger to 8-10 degrees C. Brain temperature was measured in both cerebral hemispheres. Body temperature was measured in rectum, oesophagus and the right atrium. The pigs were normoventilated and haemodynamic variables were measured continuously. Acid-base and electrolyte status was measured hourly. RESULTS: Cerebral hypothermia was induced rapidly and within the first 20 min of cooling cerebral temperature was lowered from 38.1+/-0.6 degrees C by a mean of 2.8+/-0.6 to 35.3+/-0.6 degrees C. Cooling was maintained for 6 h and the final brain temperature was 34.7+/-0.9 degrees C. Concomitantly, the body temperature, as reflected by oesophageal temperature was decreased from 38.3+/-0.5 to 36.6+/-0.9 degrees C. No circulatory or metabolic disturbances were noted. CONCLUSIONS: Inducing selective brain hypothermia with cold saline via nasal balloon catheters can effectively be accomplished in pigs, with no major disturbances in systemic circulation or physiological variables. The temperature gradients between brain and body can be maintained for at least 6 h.

    Keywords
    Brain ischaemia, Brain injury, Cardiac arrest, Cerebral blood flow, Hypothermia, Selective brain cooling, Temperature
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-100190 (URN)10.1016/j.resuscitation.2007.07.002 (DOI)000253204500016 ()17709167 (PubMedID)
    Available from: 2009-03-26 Created: 2009-03-26 Last updated: 2017-12-13Bibliographically approved
    2. Intranasal cooling with or without intravenous cold fluids during and after cardiac arrest in pigs
    Open this publication in new window or tab >>Intranasal cooling with or without intravenous cold fluids during and after cardiac arrest in pigs
    2010 (English)In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 54, no 4, p. 494-501Article in journal (Refereed) Published
    Abstract [en]

    Background: Intranasal balloon catheters circulated with cold saline have previously been used for the induction and maintenance of selective brain cooling in pigs with normal circulation. In the present study, we investigated the feasibility of therapeutic hypothermia initiation, maintenance and rewarming using such intranasal balloon catheters with or without addition of intravenous ice-cold fluids during and after cardiac arrest treatment in pigs. Material and methods: Cardiac arrest was induced in 20 anaesthetised pigs. Following 8 min of cardiac arrest and 1 min of cardiopulmonary resuscitation (CPR), cooling was initiated after randomisation with either intranasal cooling (N) or combined with intravenous ice-cold fluids (N+S). Hypothermia was maintained for 180 min, followed by 180 min of rewarming. Brain and oesophageal temperatures, haemodynamic variables and intracranial pressure (ICP) were recorded. Results: Brain temperatures reductions after cooling did not differ (3.8 +/- 0.7 degrees C in the N group and 4.3 +/- 1.5 degrees C in the N+S group; P=0.47). The corresponding body temperature reductions were 3.6 +/- 1.2 degrees C and 4.6 +/- 1.5 degrees C (P=0.1). The resuscitation outcome was similar in both groups. Mixed venous oxygen saturation was lower in the N group after cooling and rewarming (P=0.024 and 0.002, respectively) as compared with the N+S group. ICP was higher after rewarming in the N group (25.2 +/- 2.9 mmHg; P=0.01) than in the N+S group (15.7 +/- 3.3 mmHg). Conclusions: Intranasal balloon catheters can be used for therapeutic hypothermia initiation, maintenance and rewarming during CPR and after successful resuscitation in pigs.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-113241 (URN)10.1111/j.1399-6576.2009.02157.x (DOI)000274932800017 ()19912127 (PubMedID)
    Available from: 2010-01-26 Created: 2010-01-26 Last updated: 2017-12-12Bibliographically approved
    3. Noninvasive monitoring of brain temperature during mild hypothermia
    Open this publication in new window or tab >>Noninvasive monitoring of brain temperature during mild hypothermia
    Show others...
    2009 (English)In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 27, no 7, p. 923-932Article in journal (Refereed) Published
    Abstract [en]

    The main purpose of this study was to verify the feasibility of brain temperature mapping with high-spatial- and reduced-spectral-resolution magnetic resonance spectroscopic imaging (MRSI). A secondary goal was to determine the temperature coefficient of water chemical shift in the brain with and without internal spectral reference. The accuracy of the proposed MRSI method was verified using a water and vegetable oil phantom. Selective decrease of the brain temperature of pigs was induced by intranasal cooling. Temperature reductions between 2 degrees C and 4 degrees C were achieved within 20 min. The relative changes in temperature during the cooling process were monitored using MRSI. The reference temperature was measured with MR-compatible fiber-optic probes. Single-voxel (1)H MRS was used for measurement of absolute brain temperature at baseline and at the end of cooling. The temperature coefficient of the water chemical shift of brain tissue measured by MRSI without internal reference was -0.0192+/-0.0019 ppm/degrees C. The temperature coefficients of the water chemical shift relative to N-acetylaspartate, choline-containing compounds and creatine were -0.0096+/-0.0009, -0.0083+/-0.0007 and -0.0091+/-0.0011 ppm/degrees C, respectively. The results of this study indicate that MRSI with high spatial and reduced spectral resolutions is a reliable tool for monitoring long-term temperature changes in the brain.

    Keywords
    Selective brain cooling, Hypothermia, Temperature mapping, Spectroscopy, Spectroscopic imaging
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-113253 (URN)10.1016/j.mri.2009.01.011 (DOI)000269613000005 ()19282122 (PubMedID)
    Available from: 2010-01-26 Created: 2010-01-26 Last updated: 2017-12-12Bibliographically approved
    4. Brain temperature in healthy volunteers subjected to intranasal cooling
    Open this publication in new window or tab >>Brain temperature in healthy volunteers subjected to intranasal cooling
    Show others...
    2011 (English)In: Intensive Care Medicine, ISSN 0342-4642, E-ISSN 1432-1238, Vol. 37, no 8, p. 1277-1284Article in journal (Other academic) Published
    Abstract [en]

    Purpose:

    Intranasal cooling can be used to initiate therapeutic hypothermia. However, direct measurement of brain temperature is difficult and the intra-cerebral distribution of temperature changes with cooling is unknown. The purpose of this study was to measure the brain temperature of human volunteers subjected to intranasal cooling using non-invasive magnetic resonance (MR) methods.

    Methods:

    Intranasal balloons catheters circulated with saline at 20 °C were applied for 60 min in 10 healthy, unsedated volunteers. Brain temperature changes were measured and mapped using MR spectroscopic imaging (MRSI) and phase-mapping techniques. Heart rate and blood pressure were monitored throughout the experiment. Rectal temperature was measured before and after the cooling. Mini Mental State Examination (MMSE) test and nasal inspection were done before and after the cooling. Questionnaires about the subjects personal experience were filled after the experiment.

    Results:

    Brain temperature decrease measured by MRSI was -1.7 ± 0.8°C and by phase-mapping -1.8 ± 0.9°C at the end of cooling. Spatial distribution of temperature changes was relatively uniform. Rectal temperature decreased by -0.5 ± 0.3°C. The physiological parameters were stable and no shivering was reported. The volunteers remained alert during cooling and no cognitive dysfunctions were apparent at MMSE test. Postcooling nasal examination detected increased nasal secretion in 9 of the 10 volunteers. Volunteer’s acceptance of the method was good.   

    Conclusion:

    Both MR techniques revealed brain temperature reductions after 60 min intranasal cooling with balloons circulated with saline at 20 °C in healthy and unsedated volunteers.

    Keywords
    Therapeutic hypothermia, Brain temperature, Magnetic resonance spectroscopy, selective brain cooling, trigeminal reflex
    National Category
    Anesthesiology and Intensive Care
    Research subject
    Anaesthesiology and Intensive Care
    Identifiers
    urn:nbn:se:uu:diva-134228 (URN)10.1007/s00134-011-2264-7 (DOI)21647717 (PubMedID)
    Available from: 2010-11-23 Created: 2010-11-23 Last updated: 2017-12-12Bibliographically approved
  • 2.
    Covaciu, Lucian
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Allers, M.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lunderquist, A.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Wieloch, T.
    Rubertsson, Sten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Intranasal selective brain cooling in pigs2008In: Resuscitation, ISSN 0300-9572, E-ISSN 1873-1570, Vol. 78, no 1, p. 83-88Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Special clinical situations where general hypothermia cannot be recommended but can be a useful treatment demand a new approach, selective brain cooling. The purpose of this study was to selectively cool the brain with cold saline circulating in balloon catheters introduced into the nasal cavity in pigs. MATERIAL AND METHODS: Twelve anaesthetised pigs were subjected to selective cerebral cooling for a period of 6 h. Cerebral temperature was lowered by means of bilaterally introduced nasal balloon catheters perfused with saline cooled by a heat exchanger to 8-10 degrees C. Brain temperature was measured in both cerebral hemispheres. Body temperature was measured in rectum, oesophagus and the right atrium. The pigs were normoventilated and haemodynamic variables were measured continuously. Acid-base and electrolyte status was measured hourly. RESULTS: Cerebral hypothermia was induced rapidly and within the first 20 min of cooling cerebral temperature was lowered from 38.1+/-0.6 degrees C by a mean of 2.8+/-0.6 to 35.3+/-0.6 degrees C. Cooling was maintained for 6 h and the final brain temperature was 34.7+/-0.9 degrees C. Concomitantly, the body temperature, as reflected by oesophageal temperature was decreased from 38.3+/-0.5 to 36.6+/-0.9 degrees C. No circulatory or metabolic disturbances were noted. CONCLUSIONS: Inducing selective brain hypothermia with cold saline via nasal balloon catheters can effectively be accomplished in pigs, with no major disturbances in systemic circulation or physiological variables. The temperature gradients between brain and body can be maintained for at least 6 h.

  • 3.
    Covaciu, Lucian
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Allers, M.
    Lunderquist, A.
    Rubertsson, Sten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Intranasal cooling with or without intravenous cold fluids during and after cardiac arrest in pigs2010In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 54, no 4, p. 494-501Article in journal (Refereed)
    Abstract [en]

    Background: Intranasal balloon catheters circulated with cold saline have previously been used for the induction and maintenance of selective brain cooling in pigs with normal circulation. In the present study, we investigated the feasibility of therapeutic hypothermia initiation, maintenance and rewarming using such intranasal balloon catheters with or without addition of intravenous ice-cold fluids during and after cardiac arrest treatment in pigs. Material and methods: Cardiac arrest was induced in 20 anaesthetised pigs. Following 8 min of cardiac arrest and 1 min of cardiopulmonary resuscitation (CPR), cooling was initiated after randomisation with either intranasal cooling (N) or combined with intravenous ice-cold fluids (N+S). Hypothermia was maintained for 180 min, followed by 180 min of rewarming. Brain and oesophageal temperatures, haemodynamic variables and intracranial pressure (ICP) were recorded. Results: Brain temperatures reductions after cooling did not differ (3.8 +/- 0.7 degrees C in the N group and 4.3 +/- 1.5 degrees C in the N+S group; P=0.47). The corresponding body temperature reductions were 3.6 +/- 1.2 degrees C and 4.6 +/- 1.5 degrees C (P=0.1). The resuscitation outcome was similar in both groups. Mixed venous oxygen saturation was lower in the N group after cooling and rewarming (P=0.024 and 0.002, respectively) as compared with the N+S group. ICP was higher after rewarming in the N group (25.2 +/- 2.9 mmHg; P=0.01) than in the N+S group (15.7 +/- 3.3 mmHg). Conclusions: Intranasal balloon catheters can be used for therapeutic hypothermia initiation, maintenance and rewarming during CPR and after successful resuscitation in pigs.

  • 4.
    Covaciu, Lucian
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Rubertsson, Sten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Weis, Jan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Human brain MR spectroscopy thermometry using metabolite aqueous-solution calibrations2010In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 31, no 4, p. 807-814Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To estimate absolute brain temperature using proton MR spectroscopy ((1)H-MRS) and mean brain-body temperature difference of healthy human volunteers. MATERIALS AND METHODS: Chemical shift difference between temperature-dependent water spectral line position and temperature-stable metabolite spectral reference was used for the estimations of absolute brain temperature. Temperature calibrations constants were obtained from the spectra of the N-acetyl aspartate (NAA line at approximately 2.0 ppm), glycero-phosphocholine (GPC line at approximately 3.2 ppm), and creatine (Cr line at approximately 3.0 ppm) aqueous solutions with pH values within physiologically pertinent ranges. Single-voxel PRESS sequence (TR/TE 2000/80 ms) was used for this purpose. Brain temperature was determined by averaging the temperatures computed from water-Cho, water-Cr, and water-NAA chemical shift differences. RESULTS: The mean brain temperature of 18 healthy volunteers was 38.1 +/- 0.4 degrees C and mean brain-body (rectal) temperature difference was 1.3 +/- 0.4 degrees C. CONCLUSION: Improved accuracy of the temperature constants and averaging the temperatures computed from water-Cho, water-Cr, and water-NAA chemical shift differences increased the reliability of the brain temperature estimations.

  • 5.
    Covaciu, Lucian
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Weis, Jan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Bengtsson, Caroline
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Allers, M
    Lunderquist, A
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Rubertsson, Sten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Brain temperature in volunteers subjected to intranasal cooling2011In: Intensive Care Medicine, ISSN 0342-4642, E-ISSN 1432-1238, Vol. 37, no 8, p. 1277-1284Article in journal (Refereed)
    Abstract [en]

    Intranasal cooling can be used to initiate therapeutic hypothermia. However, direct measurement of brain temperature is difficult and the intra-cerebral distribution of temperature changes with cooling is unknown. The purpose of this study was to measure the brain temperature of human volunteers subjected to intranasal cooling using non-invasive magnetic resonance (MR) methods. Intranasal balloons catheters circulated with saline at 20A degrees C were applied for 60 min in ten awake volunteers. No sedation was used. Brain temperature changes were measured and mapped using MR spectroscopic imaging (MRSI) and phase-mapping techniques. Heart rate and blood pressure were monitored throughout the experiment. Rectal temperature was measured before and after the cooling. Mini Mental State Examination (MMSE) test and nasal inspection were done before and after the cooling. Questionnaires about the subjects' personal experience were completed after the experiment. Brain temperature decrease measured by MRSI was -1.7 +/- A 0.8A degrees C and by phase-mapping -1.8 +/- A 0.9A degrees C (n = 9) at the end of cooling. Spatial distribution of temperature changes was relatively uniform. Rectal temperature decreased by -0.5 +/- A 0.3A degrees C (n = 5). The physiological parameters were stable and no shivering was reported. The volunteers remained alert during cooling and no cognitive dysfunctions were apparent in the MMSE test. Postcooling nasal examination detected increased nasal secretion in nine of the ten volunteers. Volunteers' acceptance of the method was good. Both MR techniques revealed brain temperature reductions after 60 min of intranasal cooling with balloons circulated with saline at 20A degrees C in awake, unsedated volunteers.

  • 6.
    Covaciu, Lucian
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Weis, Jan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Bengtsson, Caroline
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Allers, Mats
    Division of thoracic sciences, Department of clinical sciences, Lund University.
    Lunderquist, Anders
    Department of radiology, Lund University.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Rubertsson, Sten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Brain temperature in healthy volunteers subjected to intranasal cooling2011In: Intensive Care Medicine, ISSN 0342-4642, E-ISSN 1432-1238, Vol. 37, no 8, p. 1277-1284Article in journal (Other academic)
    Abstract [en]

    Purpose:

    Intranasal cooling can be used to initiate therapeutic hypothermia. However, direct measurement of brain temperature is difficult and the intra-cerebral distribution of temperature changes with cooling is unknown. The purpose of this study was to measure the brain temperature of human volunteers subjected to intranasal cooling using non-invasive magnetic resonance (MR) methods.

    Methods:

    Intranasal balloons catheters circulated with saline at 20 °C were applied for 60 min in 10 healthy, unsedated volunteers. Brain temperature changes were measured and mapped using MR spectroscopic imaging (MRSI) and phase-mapping techniques. Heart rate and blood pressure were monitored throughout the experiment. Rectal temperature was measured before and after the cooling. Mini Mental State Examination (MMSE) test and nasal inspection were done before and after the cooling. Questionnaires about the subjects personal experience were filled after the experiment.

    Results:

    Brain temperature decrease measured by MRSI was -1.7 ± 0.8°C and by phase-mapping -1.8 ± 0.9°C at the end of cooling. Spatial distribution of temperature changes was relatively uniform. Rectal temperature decreased by -0.5 ± 0.3°C. The physiological parameters were stable and no shivering was reported. The volunteers remained alert during cooling and no cognitive dysfunctions were apparent at MMSE test. Postcooling nasal examination detected increased nasal secretion in 9 of the 10 volunteers. Volunteer’s acceptance of the method was good.   

    Conclusion:

    Both MR techniques revealed brain temperature reductions after 60 min intranasal cooling with balloons circulated with saline at 20 °C in healthy and unsedated volunteers.

  • 7.
    Gavali, Hamid
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Vascular Surgery.
    Mani, Kevin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Vascular Surgery.
    Tegler, Gustaf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Vascular Surgery.
    Kawati, Rafael
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Covaciu, Lucian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Wanhainen, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Vascular Surgery.
    Editor's Choice - Prolonged ICU Length of Stay after AAA Repair: Analysis of Time Trends and Long-term Outcome2017In: European Journal of Vascular and Endovascular Surgery, ISSN 1078-5884, E-ISSN 1532-2165, Vol. 54, no 2, p. 157-163Article in journal (Refereed)
    Abstract [en]

    Objective: The aim of the study was to investigate the frequency and outcome of prolonged intensive care unit (ICU) length of stay (LOS) after abdominal aortic aneurysm (AAA) repair in the endovascular era.

    Methods: All patients operated on for AAA between 1999 and 2013 at Uppsala University hospital were identified. Data were retrieved from the Swedish Vascular registry, the Swedish Intensive Care registry, the National Population registry, and case records. Prolonged ICU LOS was defined as >= 48 h during the primary hospital stay. Patients surviving >= 48 h after AAA surgery were included in the analysis.

    Results: A total of 725 patients were identified, of whom 707 (97.5%) survived >= 48 h; 563 (79.6%) underwent intact AAA repair and 144 (20.4%) ruptured AAA repair. A total of 548 patients (77.5%) required < 48 h of intensive care, 115 (16.3%) 2-6 days and 44 (6.2%) >= 7 days. The rate of prolonged ICU LOS declined considerably over time, from 41.4% of all AAA repairs in 1999 to 7.3% in 2013 (p < .001) whereas the use of endovascular aortic repair (EVAR) increased from 6.9% in 1999 to 78.0% in 2013 (p < .001). The 30 day survival rate was 98.2% for those with < 48 h ICU stay versus 93.0% for 2-6 days versus 81.8% for >= 7 days (p < .001); the corresponding 90 day survival was 97.1% versus 86.1% versus 63.6% (p < .001) respectively. For patients surviving 90 days after repair, there was no difference in long-term survival between the groups.

    Conclusion: During the period of progressively increasing use of EVAR, a simultaneous significant reduction in frequency of prolonged ICU LOS occurred. Although prolonged ICU LOS was associated with a high short-term mortality, long-term outcome among those surviving the initial 90 days was less affected.

  • 8.
    Kawati, Rafael
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Covaciu, Lucian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Rubertsson, Sten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Hypothermia after drowning in paediatric patients2009In: Resuscitation, ISSN 0300-9572, E-ISSN 1873-1570, Vol. 80, no 11, p. 1325-1326Article in journal (Refereed)
  • 9.
    Nordmark, Johanna
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Johansson, Jacob
    Sandberg, Dan
    Huzevka, Tibor
    Covaciu, Lucian
    Mörtberg, Erik
    Rubertsson, Sten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Decreased intravascular volume following cardiac arrest: Patient observations with echocardiography during hypothermia and rewarmingManuscript (Other academic)
  • 10.
    Nordmark, Johanna
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Johansson, Jakob
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Sandberg, Dan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Granstam, Sven-Olof
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Huzevka, Tibor
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Covaciu, Lucian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Mörtberg, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Rubertsson, Sten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Assessment of intravascular volume by transthoracic echocardiography during therapeutic hypothermia and rewarming in cardiac arrest survivors2009In: Resuscitation, ISSN 0300-9572, E-ISSN 1873-1570, Vol. 80, no 11, p. 1234-1239Article in journal (Refereed)
    Abstract [en]

    AIM: To study haemodynamic effects and changes in intravascular volume during hypothermia treatment, induced by ice-cold fluids and maintained by ice-packs followed by rewarming in patients after resuscitation from cardiac arrest. MATERIALS AND METHODS: In 24 patients following successful restoration of spontaneous circulation (ROSC), hypothermia was induced with infusion of 4 degrees C normal saline and maintained with ice-packs for 26 h after ROSC. This was followed by passive rewarming. Transthoracic echocardiography was performed at 12, 24 and 48 h after ROSC to evaluate ejection fraction and intravascular volume status. Central venous pressure (CVP), central venous oxygen saturation (ScvO(2)) and serum lactate were measured. Fluid balance was calculated. RESULTS: Twelve hours after ROSC, two separate raters independently estimated that 10 and 13 out of 23 patients had a decreased intravascular volume using transthoracic echocardiography. After 24 and 48 h this number had increased further to 14 and 13 out of 19 patients and 13 and 12 out of 21 patients. Calculated fluid balance was positive (4000 ml the day 1 and 2500 ml day 2). There was no difference in ejection fraction between the recording time points. Serum lactate and ScvO(2) were in the normal range when echocardiography exams were performed. CVP did not alter over time. CONCLUSIONS: Our results support the hypothesis that inducing hypothermia following cardiac arrest, using cold intravenous fluid infusion does not cause serious haemodynamic side effects. Serial transthoracic echocardiographic estimation of intravascular volume suggests that many patients are hypovolaemic during therapeutic hypothermia and rewarming in spite of a positive fluid balance.

  • 11.
    Weis, Jan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Covaciu, Lucian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Rubertsson, Sten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Allers, Mats
    Lunderquist, Anders
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Noninvasive monitoring of brain temperature during mild hypothermia2009In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 27, no 7, p. 923-932Article in journal (Refereed)
    Abstract [en]

    The main purpose of this study was to verify the feasibility of brain temperature mapping with high-spatial- and reduced-spectral-resolution magnetic resonance spectroscopic imaging (MRSI). A secondary goal was to determine the temperature coefficient of water chemical shift in the brain with and without internal spectral reference. The accuracy of the proposed MRSI method was verified using a water and vegetable oil phantom. Selective decrease of the brain temperature of pigs was induced by intranasal cooling. Temperature reductions between 2 degrees C and 4 degrees C were achieved within 20 min. The relative changes in temperature during the cooling process were monitored using MRSI. The reference temperature was measured with MR-compatible fiber-optic probes. Single-voxel (1)H MRS was used for measurement of absolute brain temperature at baseline and at the end of cooling. The temperature coefficient of the water chemical shift of brain tissue measured by MRSI without internal reference was -0.0192+/-0.0019 ppm/degrees C. The temperature coefficients of the water chemical shift relative to N-acetylaspartate, choline-containing compounds and creatine were -0.0096+/-0.0009, -0.0083+/-0.0007 and -0.0091+/-0.0011 ppm/degrees C, respectively. The results of this study indicate that MRSI with high spatial and reduced spectral resolutions is a reliable tool for monitoring long-term temperature changes in the brain.

  • 12.
    Weis, Jan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Covaciu, Lucian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Rubertsson, Sten
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Allers, Mats
    Lunderquist, Anders
    Ortiz-Nieto, Francisco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology.
    Phase-difference and spectroscopic imaging for monitoring of human brain temperature during cooling2012In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 30, no 10, p. 1505-1511Article in journal (Refereed)
    Abstract [en]

    Decrease of the human brain temperature was induced by intranasal cooling. The main purpose of this study was to compare the two magnetic resonance methods for monitoring brain temperature changes during cooling: phase-difference and magnetic resonance spectroscopic imaging (MRSI) with high spatial resolution. Ten healthy volunteers were measured. Selective brain cooling was performed through nasal cavities using saline-cooled balloon catheters. MRSI was based on a radiofrequency spoiled gradient echo sequence. The spectral information was encoded by incrementing the echo time of the subsequent eight image records. Reconstructed voxel size was 1×1×5 mm3. Relative brain temperature was computed from the positions of water spectral lines. Phase maps were obtained from the first image record of the MRSI sequence. Mild hypothermia was achieved in 15–20 min. Mean brain temperature reduction varied in the interval <−3.0; − 0.6>°C and <−2.7; − 0.7>°C as measured by the MRSI and phase-difference methods, respectively. Very good correlation was found in all locations between the temperatures measured by both techniques except in the frontal lobe. Measurements in the transversal slices were more robust to the movement artifacts than those in the sagittal planes. Good agreement was found between the MRSI and phase-difference techniques.

1 - 12 of 12
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf