Hypertonic resuscitation of hypovolemic shock after blunt trauma: a randomized controlled trial.

BACKGROUND: The leading cause of late mortality after trauma is multiple organ failure syndrome, due to a dysfunctional inflammatory response early after injury. Preclinical studies demonstrate that hypertonicity alters the activation of inflammatory cells, leading to reduction in organ injury. The purpose of this study was to evaluate the effect of hypertonicity on organ injury after blunt trauma.

DESIGN: Double-blind, randomized controlled trial from October 1, 2003, to August 31, 2005.

SETTING: Prehospital enrollment at a single level I trauma center.

PATIENTS: Patients older than 17 years with blunt trauma and prehospital hypotension (systolic blood pressure, </= 90 mm Hg).

INTERVENTIONS: Treatment with 250 mL of 7.5% hypertonic saline and 6% dextran 70 (HSD) vs lactated Ringer solution (LRS).

MAIN OUTCOME MEASURES: The primary end point was survival without acute respiratory distress syndrome (ARDS) at 28 days. Cox proportional hazards regression was used to adjust for confounding factors. A preplanned subset analysis was performed for patients requiring 10 U or more of packed red blood cells in the first 24 hours.

RESULTS: A total of 209 patients were enrolled (110 in the HSD group and 99 in the LRS group). The study was stopped for futility after the second interim analysis. Intent-to-treat analysis demonstrated no significant difference in ARDS-free survival (hazard ratio, 1.01; 95% confidence interval, 0.63-1.60). There was improved ARDS-free survival in the subset (19% of the population) requiring 10 U or more of packed red blood cells (hazard ratio, 2.18; 95% confidence interval, 1.09-4.36).

CONCLUSIONS: Although no significant difference in ARDS-free survival was demonstrated overall, there was benefit in the subgroup of patients requiring 10 U or more of packed red blood cells in the first 24 hours. Massive transfusion may be a better predictor of ARDS than prehospital hypotension. The use of HSD may offer maximum benefit in patients at highest risk of ARDS.