Hextend-perfluorocarbon cocktail inhibits mean arterial pressure response in a rabbit shock model

Hextend (HEX) is standard of care resuscitation fluid for combat-related traumatic hemorrhage. Because HEX has limited oxygen-carrying capacity, combination therapy with oxygen therapeutics could improve oxygen delivery after hemodynamic shock. We hypothesized that addition of perfluorocarbon (PFC) to HEX would improve hemodynamics and oxygen delivery marker response in a rabbit model of hemorrhagic shock.

Anesthetized New Zealand rabbits (n = 23) were randomly allocated to resuscitation with fresh whole blood (FWB), HEX, or HEX plus PFC (HEX + PFC) after 60 min of hemorrhagic hypotension. Mean arterial pressure (MAP) was sampled every 2-3 min for 120 min postinfusion; MAP profiles were modeled by a one-compartment pharmacokinetic model to determine peak MAP (Pmax), time to peak MAP (tmax), and postinfusion MAP persistence. Arterial blood was sampled every 15 min to examine pH, blood gases PO2 and pCO2, metabolites lactate and glucose, methemoglobin (metHb), and electrolytes.

Compared with FWB and HEX, HEX + PFC administration resulted in delayed peak MAP and less persistent (P < 0.0001) MAP elevation; metHb was significantly elevated (P < 0.0001) compared with FWB and HEX. There were no significant differences in PO2, pCO2, or pH. Glucose, hematocrit, and hemoglobin of both HEX and HEX + PFC were significantly lower relative to FWB. Lactate clearance was modest and transient for all treatments; base deficit was significantly more negative for HEX + PFC.

Addition of PFC to HEX did not improve hemodynamics or acidosis. Further dose- and volume-range studies are required to test efficacy of PFC in combination with HEX for hemorrhagic shock.