Low Skeletal Muscle Index And Myosteatosis As Predictors of Mortality In Critically Ill Surgical Patients

Abstract BackgroundLow muscle mass and other specific body composition indexes, assessed by computed tomography (CT), are associated with adverse outcomes after elective surgery, such as an increased risk of postoperative complications and higher mortality. However, limited information is available about the role of these indexes on short- and long-term outcomes in surgical patients admitted to the intensive care unit (ICU). The aim of the study was to assess the association of body composition indexes with 90-days mortality in this specific patient cohort.MethodsWe performed a retrospective study including adult surgical patients admitted to the ICU between 2014 and 2018 who underwent a CT scan at the time of admission. Total Muscle Area (TMA), Total Fat Area (TFA), Visceral fat area (VFA) and Intramuscular fat area (IMFA) were measured. Skeletal Muscle Index (TMA/m2), MyoSteatosis (IMFA/TMA), Sarcopenic Obesity (VFA/TMA) were then calculated. We analyzed the impact of these indexes on mortality.Results204 patients were included. Overall 90-day mortality was 28%. Log rank test and cox multivariate analysis on 90-day mortality showed a significant association of low SMI and myosteatosis with 90-days mortality. Myosteatosis was also significantly associated with prolonged mechanical ventilation and increased ICU length of stay.ConclusionsSpecific body composition indexes may predict mortality in surgical patients admitted to the ICU. Low skeletal muscle index and myosteatosis were independently associated with increased 90-day mortality.