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 h emorrhage. Rabbits were anesthetized and instrumented for 3 hours of h emodynamic 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 After stabilization, blood was withdrawn over a 5 minute period to reduce mean arterial pressure to 35 mmHg (4.7 kPa) .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 t o 1 of 5 experimental groups (n = 8 in each): (1) SHOCK (no retransfus ion); (2) TRANSFUSION (retransfusion of autologous shed blood); (3) VO LUME (retransfusion with autologous blood and infusion of an additiona l volume of normal saline equivalent to the volume of poloxamer 188 gi ven 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 anima ls in a surgery CONTROL group (n = 6) remained stable during the 3 hou r monitoring period. In contrast, none of the animals in the SHOCK gro up remained alive, confirming this to be a relevant model of trauma an d severe hemorrhagic shock. There were significantly more animals surv iving at the end of the monitoring period in the two groups that recei ved 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 TRANSFUSIO N (4 of 8) and VOLUME (2 of 8) groups. Our results suggest that poloxa mer 188 may produce a beneficial short-term effect in a rabbit model o f trauma and severe hemorrhagic shock.