42: DRAG-REDUCING POLYMERS IMPROVE CEREBROVASCULAR FUNCTION IN A SWINE TBI AND HEMORRHAGIC SHOCK MODEL

Introduction: Traumatic brain injury (TBI) with hemorrhagic shock (HS) is a major cause of death. Standard resuscitation often fails to restore cerebral blood flow (CBF), worsening intracranial pressure (ICP) and autoregulation. Drag-reducing polymers (DRPs) improved CBF and lowered ICP in rat TBI+HS; efficacy in a gyrencephalic brain was unknown. We tested DRPs in a swine polytrauma model. Methods: Yucatan minipigs received moderate acceleration–deceleration TBI plus 40% controlled hemorrhage. During the prehospital phase, animals were randomized to vehicle or DRP (7–10 ppm) followed by whole-blood transfusion. ICP, mean arterial pressure, CBF (Doppler), and cerebral tissue oxygenation (NIRS) were recorded over 4 h. At 48 h, MRI (hematoma, edema, DTI), serum GFAP and UCH-L1, and histopathology were obtained. Results: Versus vehicle, DRPs increased CBF (+32%) and cerebral perfusion pressure (+18%), improved brain compliance, and strengthened autoregulation (all p< 0.05). MRI showed smaller hematomas (−25%) and reduced axonal injury (DTI fractional anisotropy +15%). GFAP and UCH-L1 were ~30% lower with DRPs (p < 0.05), aligning with histologic neuroprotection. Conclusions: In swine TBI+HS, DRP-augmented resuscitation stabilized cerebral hemodynamics and reduced early injury, supporting DRPs as a field-ready adjunct to limit secondary brain damage.