Document Detail

Mild or moderate hypothermia, but not increased oxygen breathing, increases long-term survival after uncontrolled hemorrhagic shock in rats.
MedLine Citation:
PMID:  10921580     Owner:  NLM     Status:  MEDLINE    
OBJECTIVE: To test the hypotheses that, for uncontrolled hemorrhagic shock (UHS) in rats, mild hypothermia, compared with normothermia, would increase long-term survival as well as moderate hypothermia, oxygen breathing would increase survival further, and hypothermia and oxygen would mitigate visceral ischemia (dysoxia) during UHS. DESIGN: Prospective, randomized study. SETTING: Animal research laboratory. SUBJECTS: A total of 54 male Sprague-Dawley rats. INTERVENTIONS: Under light anesthesia and spontaneous breathing, rats underwent UHS phase I of 75 mins, with initial withdrawal of 3 mL/100 g of blood over 15 mins, followed by UHS via tail amputation and limited fluid resuscitation to maintain mean arterial pressure at > or =40 mm Hg; resuscitation phase II of 60 mins (from 75 mins to 135 mins) with hemostasis and aggressive fluid resuscitation to normalize hemodynamics; and observation phase III to 72 hrs. Rats were randomly divided into nine groups (n = 6 each) with three rectal temperature levels (38 degrees C [normothermia] vs. 34 degrees C [mild hypothermia] vs. 30 degrees C [moderate hypothermia]) by surface cooling; each with 3 FIO2 levels (0.25 vs. 0.5 vs. 1.0). MEASUREMENTS AND MAIN RESULTS: Hypothermia increased blood pressure compared with normothermia. Increased FIO2 had no effect on blood pressure. Additional blood loss from the tail cut was small, with no differences among groups. Hypothermia and FIO2 of 0.5 decreased visceral hypoxia, as measured by the difference between visceral (liver and jejunum) surface Pco2 and PaCO2 during UHS. Compared with normothermia, mild hypothermia increased the survival time and rate as well as moderate hypothermia (p < .01 by life table), without a significant difference between mild and moderate hypothermia. Increased FIO2 had no effect on survival time or rate. CONCLUSIONS: After severe UHS and resuscitation in rats, mild hypothermia during UHS, compared with normothermia, increases blood pressure, survival time and 72-hr survival rate as well as moderate hypothermia. Mild hypothermia is clinically more feasible and safer than moderate hypothermia. Increased FIO2 seems to have no significant effect on outcome.
A Takasu; S W Stezoski; J Stezoski; P Safar; S A Tisherman
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Critical care medicine     Volume:  28     ISSN:  0090-3493     ISO Abbreviation:  Crit. Care Med.     Publication Date:  2000 Jul 
Date Detail:
Created Date:  2000-08-16     Completed Date:  2000-08-16     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0355501     Medline TA:  Crit Care Med     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  2465-74     Citation Subset:  AIM; IM    
Safar Center for Resuscitation Research and the Department of Anesthesiology/Critical Care Medicine, University of Pittsburgh School of Medicine, PA, USA.
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MeSH Terms
Blood Gas Analysis
Blood Glucose
Fluid Therapy
Hypothermia, Induced*
Lactates / blood
Rats, Sprague-Dawley
Shock, Hemorrhagic / mortality,  physiopathology,  therapy*
Survival Rate
Reg. No./Substance:
0/Blood Glucose; 0/Lactates

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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