Brain oxygenation with a non-vasoactive perfluorocarbon emulsion in a rat model of traumatic brain injury

The aim of this study was to assess, in two experiments, the safety and efficacy of the PFC emulsion Oxycyte as an oxygen therapeutic for TBI to test the hypothesis that early administration of this oxygen-carrying fluid post-TBI would improve brain tissue oxygenation (P_bt O₂ ).

The first experiment assessed the effects of Oxycyte on cerebral vasoactivity in healthy, uninjured rats using intravital microscopy. The second experiment investigated the effect of Oxycyte on cerebral P_bt O₂ using the PQM in TBI model. Animals in the Oxycyte group received a single injection of Oxycyte (6 mL/kg) shortly after TBI, while NON animals received no treatment.

Oxycyte did not cause vasoconstriction in small- (<50 μm) or medium- (50-100 μm) sized pial arterioles nor did it cause a significant change in blood pressure. Treatment with Oxycyte while breathing 100% O₂ did not improve P_bt O₂ . However, in rats ventilated with ~40% O₂ , P_bt O₂ improved to near pre-TBI values within 105 minutes after Oxycyte injection.

Although Oxycyte did not cause cerebral vasoconstriction, its use at the dose tested while breathing 100% O₂ did not improve P_bt O₂ following TBI. However, Oxycyte treatment while breathing a lower enriched oxygen concentration may improve P_bt O₂ after TBI.