To investigate the predictive value of computed tomography (CT)-based transverse diameter (TD) and longitudinal diameter (LD) of the psoas muscle at the level of third lumbar vertebra for in-hospital mortality in elderly sepsis patients.

Sarcopenia or loss of muscle mass is strongly associated with unfavorable prognosis in patients with sepsis. Measurement of muscle mass in patients, particularly during the initial stages of the disease, holds the potential to identify patients with poor prognoses and facilitate timely interventions.Limited studies have explored the prognostic value of CT parameters in sepsis patients, with even fewer focusing on elderly patients.

This retrospective single-center cohort study included 115 elderly sepsis patients admitted to ICU between July 2017 and July 2022. The TD and LD of right psoas muscle were obtained by measurement on abdominal CT images. Logistic regression analysis was conducted to identify the prognostic factors for in-hospital mortality in elderly sepsis patients, and their predictive performances were evaluated using the receiver operating characteristic (ROC) curve.

Multivariate logistic analysis indicated that TD (OR: 0.390, 95% CI: 0.164-0.926) was a protective factor for in-hospital mortality in elderly sepsis patients after adjusting for illness severity and treatment. The areas under the curve (AUCs) of TD, APACHE II, and SOFA were 0.667 (95% CI: 0.568-0.767), 0.674 (95% CI; 0.575-0.773), and 0.695 (95% CI: 0.600-0.791), respectively. Additionally, the AUC increased to 0.791 (95% CI: 0.709–0.873) when TD was combined with SOFA scores.

The TD of psoas muscle was a predictor for in-hospital mortality in elderly patients with sepsis. Furthermore, the integration of TD with SOFA scores enhances the early identification of patients at high risk for poor prognosis.