Background: We studied the effects of early versus delayed fluid resuscitation on hemodynamic response and short-term survival in a porcine model of severe hepatic injury associated with hemorrhagic shock.
Materials and methods: Eighteen anesthetized swine were randomized after standardized liver injury into two groups: early resuscitation (ER, n = 9) and delayed resuscitation (DR, n = 9). The ER and DR groups were resuscitated with hypertonic saline dextran (HSD) 20 min and 40 min after the injury, respectively. Mean arterial pressure (MAP), cardiac output (CO), and arterial blood gases were measured in addition to vascular blood flow rates in the aorta, hepatic artery and portal vein. The duration of follow-up was 100 min.
Results: MAP decreased from 112 +/- 4 to 23 +/- 2 mmHg (P < 0.05) during 20 min after the injury. Bolus infusion of HSD significantly elevated MAP, CO, and flow rates in the aorta, portal vein and common hepatic artery in both groups. Portal vein flow remained relatively high during the shock. Intra-abdominal bleeding (ER, 701 +/- 42 mL; DR 757 +/- 78 mL) and the mortality rate (ER 44%; DR 33%) did not differ between the groups 100 min after injury (P > 0.05). Aortic flow, portal vein flow, common hepatic artery flow, MAP, CO, PaO(2), PaCO(2), base deficit, pH, hemoglobin measurements, and the volume of blood shed into the intraperitoneal cavity did not affect survival in the Cox regression analysis.
Conclusions: Early versus delayed fluid infusion with HSD resulted in a comparable hemodynamic response and survival 100 min after injury. No rebleeding was observed.