Caution About Vasopressor Use in Hemorrhagic Shock

Crystalloid resuscitation is a mainstay in the management of post-traumatic hemorrhagic shock, but excessive fluid administration might increase or aggravate coagulopathy, abdominal compartment syndrome, pulmonary and cardiac dysfunction, gastrointestinal ileus, and bowel anastomotic complications. These risks, coupled with hemorrhagic-shock research in animal models that has demonstrated a benefit of vasopressin and phenylephrine compared with crystalloid alone, have prompted increased exploration of the use of vasopressors. Investigators used data from a prospective multicenter cohort study (Inflammation and the Host Response to Injury program) to evaluate use of early vasopressor therapy and aggressive early crystalloid resuscitation in trauma patients.

Patients admitted to seven U.S. institutions between 2003 and 2007 were eligible if they were aged 16 to 90 and had a blunt mechanism of injury, systolic blood pressure <90 mm Hg prehospital or in the emergency department or elevated base deficit (≥6 mEq/L) in the ED, blood transfusion requirement within the first 12 hours of injury, and any body region other than the brain with an Abbreviated Injury Scale score ≥2. Mortality rates were compared between patients who did and did not receive early (within 12 hours of injury) vasopressor therapy (Levophed, phenylephrine, dopamine, or vasopressin) and between patients who did and did not receive aggressive early crystalloid resuscitation (≥16 L within 12 hours post-injury). Analyses were controlled for important physiologic, injury, resuscitation, and demographic parameters.

Among 921 patients, the overall mortality rate was 12% and the mean Injury Severity Scale score was 31. Use of vasopressors (any of the 4 studied) within 12 hours after injury, compared with no use of vasopressors, was associated with an increased mortality risk (hazard ratio, 1.81), as was use of vasopressors within 24 hours after injury (HR, 2.15). Aggressive early crystalloid resuscitation within 12 hours, compared with no use of crystalloid resuscitation, was associated with a reduction in mortality (HR, 0.59). In analysis by age (≤55 vs. >55), the only significant finding was a protective effect of aggressive early crystalloid resuscitation in the younger group (HR, 0.54).