Abstract 15905: Vasopressin Infusion during Severe Hemorrhagic Shock Increases Systemic Blood Flow and Markedly Improves Survival in a Swine Model
Background: We recently developed a swine model of hemorrhagic shock (HS) to investigate protective effects of erythropoietin. A 50% reduction in blood volume (BV) triggered an adaptive response that maintained O2 consumption resulting in minimal arterial lactate increases (1.5±0.5 to 2.4±1.8 mmol/l; p<0.01) and 83% survival at 72 hours. Removal of an additional 15% BV exhausted the adaptive response causing lactic acidosis and reducing survival to 25%. Seeking a severe but not lethal HS model, we added vasopressin infusion observing a dramatic improvement in outcome; as herein reported.
Methods: The previous series without vasopressin (Series No-VP) was compared with a current series with vasopressin (Series VP). Both series had 50% and then 15% of the BV removed followed by observation without fluid intervention (Figure). Thereafter, Series No-VP received normal saline (NS) - threefold the BV removed - over 240 min followed by blood reinfusion; Series VP received NS - half the BV removed in half of the pigs - over 60 min followed by blood reinfusion. In Series VP, vasopressin was given intraosseously as bolus (0.04 U/kg) followed by infusion (0.04 U/kg·min-1) from the start of 15% BV removal until the start of blood reinfusion (120 min).
Results: In Series No-VP, only 25% survived with most deaths occurring during the additional 15% BV removal and subsequent observation without NS administration (Figure). In Series VP, 100% survived the HS and resuscitation intervals with 80% alive and functionally intact at 72 hours; two survivors had to be euthanized (at 24 and 48 hours) for inability to ambulate. Series VP had higher cardiac index (2.4±1.0 vs 3.7±1.3 l/m-2; p=0.02) with numerically lower arterial lactate (6.0±3.9 vs 5.4±3.3 mmol/l; p=0.68) at the end of HS (min 90).
Conclusions: Vasopressin increased cardiac index during severe HS without exacerbating lactic acidosis - suggesting an effect on capacitance vessels - and dramatically improved outcome.
- © 2012 by American Heart Association, Inc.