Emergency Department Hypotension is not an independent risk factor for post-traumatic acute renal dysfunction

BACKGROUND: Hypotension has been considered to be associated with renal dysfunction. The purpose of this study was to characterize the association of Emergency Department Hypotension (EDHypo) with post-traumatic renal insufficiency (RI) and renal failure (RF). METHODS: A Level I center Intensive Care Unit database was analyzed. We reviewed all adult trauma patients surviving for more than 24 hours. EDHypo was defined as admission systolic blood pressure of less than 90 mm Hg, RI was defined as a peak serum creatine of ≥2.0 mg/dL, RF was defined as requiring dialysis. RESULTS: There were 2,574 admissions studied and RI occurred in 8.3% (213) of these patients whereas RF occurred in 1.1% (28). The mortality rate with RI was 41.0% (89) and 50.0% (14) with RF. There was no significant change in the incidence of RI, RF, or RI associated mortality during the study period. EDHypo was present in 7.9% (203) of patients and the incidence of RI was significantly higher than that of non-EDHypo patients (12.2% vs. 7.9%, p = 0.028). The incidence of RF was not different (1.0% vs. 1.1%). EDHypo was not independently associated with RI or RF but Injury Severity Score >16, renal injury, age >55, Body Mass Index >30, male gender, and Intensive Care Unit (ICU) admission creatine kinase ≥5,000 U/L had an independent association with RI. No risk factor in patients with RI could reliably predict RF. CONCLUSIONS: EDhypo is not independently associated with post-traumatic RI or RF but severity of injury, renal injury, age, Body Mass Index, male gender, and elevated creatinine kinase are independently associated with RI. In critically ill trauma patients the incidence of RI and RF and the associated mortality rate has not changed significantly during a 6-year period despite, presumably, better understanding of resuscitative strategies.