Oxygen debt criteria quantify the effectiveness of early partial resuscitation after hypovolemic hemorrhagic shock.

Background: The effectiveness of partial resuscitation after hypovolemic hemorrhagic shock with deferment of full resuscitation is critical to successful hypotensive resuscitation.

Methods: To quantitatively address this issue, 40 canines were bled under anesthesia to a mean oxygen debt (O(2)D) of 104 +/- 7.6 mL/kg over 60 minutes (mortality, 40%). Animals surviving the shock were then immediately resuscitated with 0%, 8.4%, 15%, 30%, or 120% (full resuscitation) of shed volume as 5% albumin and held for 2 hours postshock, when the remaining portion of full resuscitation volume was given. Animals were followed for 7 days postshock with hepatic and renal function studies, and then, under anesthesia, cardiac output and organ biopsy specimens were taken before the animals were killed.

Results: By 2 hours postshock, 0% immediate resuscitation had an O(2)D increase of 80 mL/kg above end of shock, but O(2)D at 8.4% immediate resuscitation decreased -30 mL/kg, 15% immediate resuscitation fell -65 mL/kg, 30% immediate resuscitation decreased -80 mL/kg below end of shock, and O(2)D with 120% full resuscitation fell to preshock levels. All decreases in O(2)D were significantly (p < 0.05) below end of shock, but both 15% and 30% immediate resuscitation exceeded the 8.4% immediate resuscitation rate (p < 0.05) throughout the resuscitation, and 120% full resuscitation exceeded these (p < 0.05). The immediate resuscitation O(2)D response correlated significantly (p < 0.001) with base deficit and lactate, but blood pressure was not a significant discriminator. Seven-day biopsies showed return of bowel mucosa but a pattern of cellular injury in heart, liver, and kidney that improved from 8.4% < 15% < 30 < 120% immediate resuscitation.

Conclusion: The data suggest that, compared with 120% postshock immediate resuscitation, 8.4% and 15% immediate resuscitation give poorer results, with 30% immediate resuscitation showing mild, transient, but acceptable changes in organ function allowing for a 2-hour delay until full resuscitation, with complete 7-day recovery. Base deficit and lactate, but not blood pressure, are significant indices of O(2)D.