Effects of poloxamer 188 in a rabbit model of hemorrhagic shock

Poloxamer 188 is a synthetic surfactant that reduces the viscosity of whole blood without hemodilution. It is postulated that poloxamer 188 would improve outcome if administered during retransfusion following hemorrhage. Rabbits were anesthetized and instrumented for 3 hours of hemodynamic monitoring. After stabilization, blood was withdrawn over a 5 minute period to reduce mean arterial pressure to 35 mmHg (4.7 kPa). Following a 60 minute shock period, animals were randomly assigned to 1 of 5 experimental groups (n = 8 in each): (1) Shock (no retransfusion); (2) Transfusion (retransfusion of autologous shed blood); (3) Volume (retransfusion with autologous blood and infusion of an additional volume of normal saline equivalent to the volume of poloxamer 188 given in the next 2 experimental groups); (4) Low and (5) High drug (i.v. bolus of 200 mg/kg of poloxamer 188 over 5 minutes at retransfusion, followed by a continuous infusion of poloxamer 188 at 50 mg/kg/hr in the Low drug group and 200 mg/kg/hr in the High drug group). All animals in a surgery Control group (n = 6) remained stable during the 3 hour monitoring period. In contrast, none of the animals in the Shock group remained alive, confirming this to be a relevant model of trauma and severe hemorrhagic shock. There were significantly more animals surviving at the end of the monitoring period in the two groups that received poloxamer 188 (numbers of animals alive after 3 hours = 7 of 8 in the High group and 6 of 8 in the Low group) compared to the Transfusion (4 of 8) and Volume (2 of 8) groups.(ABSTRACT TRUNCATED AT 250 WORDS)