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

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

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.

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.

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.