Treatment of uncontrolled hemorrhagic shock after liver trauma:: Fatal effects of fluid resuscitation versus improved outcome after vasopressin

In a porcine model of uncontrolled hemorrhagic shock, we evaluated the effects of vasopressin versus an equal volume of saline placebo versus fluid resuscitation on hemodynamic variables and short-term survival. Twenty-one anesthetized pigs were subjected to severe liver injury. When mean arterial blood pressure was <20 mm Hg and heart rate decreased, pigs randomly received either vasopressin IV (0.4 U/kg; n = 7), an equal volume of saline placebo (n = 7), or fluid resuscitation (1000 mL each of lactated Ringer's solution and hetastarch; n = 7). Thirty minutes after intervention, surviving pigs were fluid resuscitated while bleeding was surgically controlled. Mean (+/- SEM) arterial blood pressure 5 min after the intervention was significantly (P < 0.05) higher after vasopressin than with saline placebo or fluid resuscitation (58 +/- 9 versus 7 +/- 3 versus 32 +/- 6 mm Hg, respectively). Vasopressin improved abdominal organ blood flow but did not cause further blood loss (vasopressin versus saline placebo versus fluid resuscitation 10 min after intervention, 1343 +/- 60 versus 1350 +/- 22 versus 2536 93 mL, respectively; P < 0.01). Seven of 7 vasopressin pigs survived until bleeding was controlled and 60 min thereafter, whereas 7 of 7 saline placebo and 7 of 7 fluid resuscitation pigs died (P < 0.01). We conclude that vasopressin, but not saline placebo or fluid resuscitation, significantly improves short-term survival during uncontrolled hemorrhagic shock.