The Prevalence of Sarcopenia in Patients With Respiratory Failure Classified as Normally Nourished Using Computed Tomography and Subjective Global Assessment

Background: Declines in nutrition status and adverse body composition changes frequently occur in the critically ill. The objective of this cross-sectional study was to examine the prevalence of sarcopenia and its occurrence in patients classified as normal nourished using subjective global assessment (SGA). Methods: Exploiting diagnostic CT images, skeletal muscle mass at the L3 region was quantified and used to determine sarcopenia and its association with normal nutrition status in 56 patients with respiratory failure. Sarcopenia was defined as an L3 skeletal muscle index of 38.5 cm(2)/m(2) for women and 52.4 cm(2)/m(2) for men. CT imaging and SGA classifications completed within 14, 10 and 7 days of each other were analyzed to assess sarcopenia and the influence of time between scans on misclassification (ie, normal nourished and sarcopenic). Descriptive statistics were conducted. Results: The average patient was 59.2 (+/- 15.6) years old, admitted with sepsis/infection, an APACHE II score of 26 (+/- 8.0), and BMI of 28.3 (+/- 5.8). Sarcopenia and sarcopenic obesity were prevalent in a minimum of 56% and 24% of patients, respectively, depending on the number of days between CT imaging and SGA assessment. Misclassified individuals were predominantly male, minority and overweight or obese. Controlling for age, no significant differences were noted for patients classified as normal nourished vs malnourished by SGA for lumbar muscle cross-sectional, whole-body lean mass, or skeletal muscle index. Conclusions: Sarcopenia is highly prevalent among patients with respiratory failure requiring mechanical ventilation (MV) and not readily detected in patients classified as normal nourished using SGA.