Published ahead of print on December 12, 2002, doi:10.1164/rccm.200205-490OC
© 2003 American Thoracic Society
Critical Oxygen Delivery in Conscious Septic Rats under Stagnant or Anemic HypoxiaAC Burton Vascular Biology Laboratory, London Health Sciences Centre, University of Western Ontario, London, Ontario, Canada Correspondence and requests for reprints should be addressed to Claudio Martin, M.Sc., M.D., London Health Sciences Centre, 375 South Street, London, ON, Canada N6A 4G5. E-mail: cmartin1{at}uwo.ca Although evidence shows that critical O2 delivery (QO2crit), the point at which oxygen consumption becomes limited by O2 delivery (QO2), is not affected by the method used to decrease QO2 in healthy subjects, microcirculatory injury caused by sepsis may modify QO2crit in a unique manner. We therefore designed this study to compare QO2crit in anemic and stagnant hypoxia in conscious septic rats. Rats were randomized to control or sepsis induced by cecal ligation and perforation; 24 hours later, oxygen consumption was measured using expired gas analysis, whereas QO2 was calculated from standard formula. Rats were further randomized to anemic hypoxia by isovolemic hemodilution or stagnant hypoxia by stepwise inflation of a balloon-tip catheter in the right atrium. QO2crit and critical hemoglobin concentration were calculated by dual linear regression analysis. We found that (1) QO2crit was not different between anemic and stagnant hypoxia in sepsis and that (2) the critical hemoglobin concentration in anemic hypoxia was similar between sepsis and control, indicating that tolerance to acute anemia is not altered by sepsis. Further studies are needed before the clinical relevance of these conclusions can be fully understood.
Key Words: oxygen consumption • cardiac output • anemic hypoxia • sepsis This article has been cited by other articles:
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