Redefining Hypotension in the Elderly

Background: Recent debate concerns the most appropriate definition of hypotension. Some have advocated raising the systolic blood pressure (BP) threshold to 110 mm Hg while others favor 80 mm Hg. Hypothesis:The optimal definition of hypotension differs by age group. Design: An analysis was performed of trauma victims 18 years and older in the National Trauma Data Bank, excluding burn injury patients and those with incomplete data. Setting:Injured patients who were hospitalized in various trauma centers across the continental United States. Patients: Three age groups were identified for analysis as follows: 18 to 35 years, 36 to 64 years, and 65 years and older. One hundred one multiple logistic regression analyses were performed for each population. Hypotension was sequentially defined as an emergency department systolic BP (SBP) of 50 to 150 mm Hg to see whichmodelbestpredictedmortality,adjustingfordemographic and injury covariates. The discriminatory power of each model was measured using the area under the receiver operating characteristic (AUROC) curve. Optimally defined hypotension was identified as the model with the highest AUROC curve. Main Outcomes Measure: In-hospital mortality.