Computed tomography measured psoas density predicts outcomes in trauma

Abstract

Age-related loss of muscle mass and function (sarcopenia) is linked to poor outcomes after operation and trauma. Here we evaluate computed tomography measured psoas muscle density and area using quick and simple tools available to the bedside clinician. We hypothesize these measures will predict poor outcomes after blunt traumatic injury. We conducted a retrospective cohort study of patients ages ≥45years in the Ohio State University Trauma Registry in 2008 that received a computed tomographic scan of the abdomen and/or pelvis with intravenous contrast. Psoas Index and Hounsfield unit average calculation were measured at the L3 level. In the study, 90-day mortality, complication, duration of stay ≥7days, and dependent discharge were compared with Psoas Index and Hounsfield unit average calculation. In the study, 151 patients met the inclusion criteria. Patients were stratified into interquartile ranges based either on Psoas Index or Hounsfield unit average calculation values. After adjustment with sex-specific cutoffs, the lowest interquartile range of Psoas Index was associated with 90-day mortality (relative risk [RR] 5.95, P<.008), but did not reach significance in other outcomes. The lowest interquartile range of Hounsfield unit average calculation was associated with 90-day mortality (RR5.95, P<.008), duration of stay≥7days (RR 1.63, P=.048), complication risk (RR 2.30, P=.002), and dependent discharge 2.14, P=.015). Psoas muscle density is a significant predictor of poor outcomes after traumatic injury. This objective, quick, and readily available measure of sarcopenia can identify patients requiring aggressive nutritional and physical therapy to improve prognosis, prevent recurrent traumatic injury, and aid in discharge planning.