Fluid resuscitation after traumatic brain injury with hypovolemic shock: Still a bloody business?*:

Prehospital Whole Blood Resuscitation Reduces Fluid Requirement While Maintaining Critical Physiology in a Model of Penetrating Traumatic Brain Injury and Hemorrhage: Implications on Resource-Limited Combat Casualty Care

ABSTRACT

Prehospital resuscitation using whole blood (WB) is the standard of care for hemorrhagic shock (HS) but there is no consensus recommendation for resuscitation in the presence of traumatic brain injury (TBI) due to a lack of sufficient evidence. In order to evaluate the optimal resuscitation strategies for TBI+HS, Sprague-Dawley rats were randomized into four groups based on resuscitation fluid and prehospital mean arterial pressure (MAP) threshold (n = 9-10/group): Lactated Ringer's (LR)-60 mm Hg (LR60), LR-70 mm Hg (LR70), WB-60 mm Hg (WB60), WB-70 mm Hg (WB70). All groups received a frontal penetrating ballistic-like brain injury followed by a 35-min period of HS. During the prehospital phase, rats received an initial bolus of resuscitation fluid (WB or LR) followed by LR as needed to maintain MAP above the designated threshold for 90 min. During the in-hospital phase, rats received definitive resuscitation with shed WB. Physiological parameters were recorded continuously and cerebral edema was measured at 3 and 24 h postinjury. The WB60 group demonstrated a significantly lower prehospital fluid requirement compared WB70, LR60, and LR70 (P < 0.05). Compared to the respective LR groups, both the WB60 and WB70 groups also demonstrated improved MAP, cerebral perfusion pressure, brain tissue oxygen tension, and cerebral edema. The edema benefits were observed at 3 h, but not 24 h postinjury, and were localized to the injury site. Together, these results provide evidence that prehospital WB resuscitation and lower MAP resuscitation thresholds can reduce the prehospital fluid requirement while still maintaining critical cerebral physiology in a model of HS and concomitant TBI.