Preinjury warfarin worsens outcome in elderly patients who fall from standing

Abstract

Introduction: Fall from standing (FFS) has become one of the most common mechanisms of injury for admission to the trauma center in the elderly population. Many of these patients present anticoagulated with warfarin. This two-center study was designed to examine the effects of preinjury warfarin use on outcome in the elderly.

Methods: A retrospective review of prospectively collected registry data at two Level I trauma centers was conducted from 2003 to 2006. The study population included patients age > or = 65 admitted to the trauma center after an FFS. These centers are relatively close geographically and have similar patient demographics. Data collected included: age, Injury Severity Score, Abbreviated Injury Score (AIS) for head, mortality, admission Glasgow Coma Score, and admission international normalized ratio (INR). Patients were divided into two groups based on the preinjury condition of warfarin use. Statistical differences were determined by unpaired t test for continuous variables and chi and odds ratios (ORs) for dichotomous variables.

Results: Of the 27,812 patients admitted to these two trauma centers over this time period, 2,791 (10.0%) were of age > or = 65 and admitted after an FFS. INR was 2.8 +/- 1.1 in warfarin group (+warf). The number of patients with AIS head 4 and 5 was similar between groups (-warf 22.1%, +warf 25.9%). Overall, preinjury warfarin use had a negative effect on the in-hospital mortality rate, +warf 8.6% and -warf 5.7% (OR 1.54, 1.09-2.19, p = 0.015). There was no difference in mortality between groups in patients with an AIS head < 4. The negative impact of preinjury warfarin use on mortality was most pronounced in patients with an AIS head 4 and 5 who presented awake (Glasgow Coma Score 14 and 15), +warf 13.5% and -warf 6.4% (OR 2.30, 95% confidence interval 1.12-4.70, p = 0.019).

Conclusion: Preinjury warfarin use has an adverse effect on outcome (mortality) in elderly FFS patients. Importantly, this effect is most prominent in patients admitted awake with significant findings on computed tomography scan. This argues for rapid emergency department triage to computed tomography scan and rapid INR correction in this population.