Vasopressin, but not fluid resuscitation enhances survival in a liver trauma model with uncontrolled and otherwise lethal hemorrhagic shock in pigs

Background: The authors compared the effects of vasopressin versus fluid resuscitation on survival in a liver trauma model with uncontrolled and otherwise lethal hemorrhagic shock in pigs. Methods. A midline laparotomy was performed on 23 domestic pigs, followed by an incision, and subsequent finger fraction across the right medial liver lobe. During hemorrhagic shock, animals were randomly assigned to receive either 0.4 U/kg vasopressin (n = 9), or fluid resuscitation (n = 7), or saline placebo (n = 7), respectively. A continuous infusion of 0.08 U . kg(-1) . min(-1) vasopressin in the vasopressin group, or normal saline was subsequently administered in the fluid resuscitation and saline placebo group, respectively. After 30 min of experimental therapy, bleeding was controlled by surgical intervention, and blood transfusion and rapid fluid infusion were subsequently performed. Results: Maximum mean arterial blood pressure during experimental therapy in the vasopressin-treated animals was significantly higher than in the fluid resuscitation and saline placebo groups (mean +/- SD, 72 +/- 26 vs. 38 +/- 16 vs. 11 +/- 7 mmHg, respectively; P < 0.05). Subsequently, mean arterial blood pressure remained at approximately 40 mmHg in all vasopressin-treated animals, whereas mean arterial blood pressure in all fluid resuscitation and saline placebo pigs was close to aortic hydrostatic pressure (similar to15 mmHg) within approximately 20 min of experimental therapy initiation. Total blood loss was significantly higher in the fluid resuscitation pigs compared with vasopressin or saline placebo after 10 min of experimental therapy (65 +/- 6 vs. 42 +/- 4 vs. 43 +/- 6 ml/kg, respectively; P < 0.05). Seven of seven fluid resuscitation, and seven of seven saline placebo pigs died within approximately 20 min of experimental therapy, while 8 of 9 vasopressin animals survived more than 7 days (P < 0.05). Conclusions: Vasopressin, but not fluid resuscitation or saline placebo, ensured survival with full recovery in this liver trauma model with uncontrolled and otherwise lethal hemorrhagic shock in pigs.