Pre-injury sarcopenia and the association with discharge destination in critical care trauma patients

Background: Sarcopenia is a key physical component in the aetiology of frailty, representing progressive and CT-quantifiable muscle mass loss. In older trauma patients admitted to critical care, sarcopenic defined-frailty is associated with adverse outcomes, including poor function at discharge. This may complicate discharge to the usual place of residence, an important outcome for patients. This study aimed to identify pre-injury sarcopenia in all trauma patients admitted to critical care and investigate factors associated with discharge destination. Methods: We performed a retrospective analysis of adult trauma patients admitted to a Major Trauma Centre (Level 1 equivalent) over 18 months. Psoas muscle density (PMD) was measured at the level of L4 vertebra from admission computerised tomography (CT) abdomen/pelvis. Sarcopenia was defined as the PMD calculated using Hounsfield unit average calculation within the lowest quartile for sex. Discharge destination was dichotomised into independent and dependent discharge. Multivariable logistic regression was used to determine factors associated with discharge destination. Results: Overall, 197 patients were included. Patients were predominantly male (73%) with a median age of 52 (32-72) and the majority were severely injured (72%). Sarcopenia was identified in a quarter of the cohort on admission to critical care (n= 49). Only a third of sarcopenic patients were discharged to home, compared to a half of non-sarcopenic patients (p= 0.03). Sarcopenia (OR 0.30; 95% CI 0.17-0.81, p= 0.01), blunt injury (OR 0.22; 95% CI 0.06-0.87, p= 0.03), age (OR 0.97; 95% CI 0.95-0.99, p= 0.01) and Multiple Organ Dysfunction Syndrome (OR 0.24; 95% CI 0.12-0.57, p= 0.01) were associated with a decreased rate of independent discharge. Conclusion: For trauma critical care patients, sarcopenia on admission CTwas associated with dependent discharge destination and therefore is unfavourable. Defining sarcopenia early in an trauma patients critical care admission may help to identify those at risk of poor outcomes.