Intraoperative hypotensive resuscitation for patients undergoing laparotomy or thoracotomy for trauma: Early termination of a randomized prospective clinical trial

Background: Hemorrhagic shock is responsible for one third of trauma related deaths. We hypothesized that intraoperative hypotensive resuscitation would improve survival for patients undergoing operative control of hemorrhage following penetrating trauma. Methods: Between July 1, 2007, and March 28, 2013, penetrating trauma patients aged 14 years to 45 years with a systolic blood pressure of 90 mm Hg or lower requiring laparotomy or thoracotomy for control of hemorrhage were randomized 1:1 based on a target minimum mean arterial pressure (MAP) of 50 mm Hg (experimental arm, LMAP) or 65 mm Hg (control arm, HMAP). Patients were followed up 30 days postoperatively. The primary outcome of mortality; secondary outcomes including stroke, myocardial infarction, renal failure, coagulopathy, and infection; and other clinical data were analyzed between study arms using univariate and Kaplan-Meier analyses. Results: The trial enrolled 168 patients (86 LMAP, 82 HMAP patients) before early termination, in part because of clinical equipoise and futility. Injuries resulted from gunshot wounds (76%) and stab wounds (24%); 90% of the patients were male, and the median age was 31 years. Baseline vitals, laboratory results, and injury severity were similar between groups. Intraoperative MAP was 65.5 ± 11.6 mm Hg in the LMAP group and 69.1 ± 13.8 mm Hg in the HMAP group (p = 0.07). No significant survival advantage existed for the LMAP group at 30 days (p = 0.48) or 24 hours (p = 0.27). Secondary outcomes were similar for the LMAP and HMAP groups: acute myocardial infarction (1% vs. 2%), stroke (0% vs. 3%), any renal failure (15% vs. 12%), coagulopathy (28% vs. 29%), and infection (59% vs. 58%) (p > 0.05 for all). Acute renal injury occurred less often in the LMAP than in HMAP group (13% vs. 30%, p = 0.01). Conclusion: This study was unable to demonstrate that hypotensive resuscitation at a target MAP of 50 mm Hg could significantly improve 30-day mortality. Further study is necessary to fully realize the benefits of hypotensive resuscitation.