(460) The Use of Computed Tomography for Malnutrition Diagnosis in Surgical and Critically Ill Patients

Introduction: Hospitalized and critically ill patients who have preexisting malnutrition can have worse outcomes and an increased length of stay (LOS). Currently, Registered Dietitians (RDs) assess malnutrition with a nutrition focused physical exam (NFPE). Recent recommendations encourage the use of body composition tools such as computed tomography (CT) along with the NFPE. Trained RDs can use CT scans to evaluate skeletal muscle mass at the third lumbar vertebrae (L3) and then calculate Skeletal Muscle Index (SMI) and mean Hounsfield Units (HU) to determine muscle size and quality, respectively. This has been validated in various clinical populations, and may be particularly useful in the critically ill where the NFPE is difficult. We aim to evaluate if using CT scans in the surgical and critical care population can be a supportive tool to capture a missed malnutrition diagnosis.

Methods: One-hundred and twenty patients admitted to the Cleveland Clinic from 2021-2023 with a malnutrition evaluation that included an NFPE within 2 days of an abdominal CT were evaluated. Of those, 59 patients had a major surgery or procedure completed that admission and were included in the final analysis. The CT scans were read by a trained RD at L3 using Terarecon, and results were cross-referenced by an artificial intelligence software (AI) called Veronai. Age, sex, BMI, SMI & HU were analyzed, along with the malnutrition diagnosis.

Results: Fifty-nine patients were analyzed. Of these, 61% were male, 51% were >65 years old, and 24% had a BMI >30. Malnutrition was diagnosed in 47% of patients. CT captured an additional 27% of patients with low muscle mass where the NFPE did not, and 17% of these patients missed a malnutrition diagnosis altogether. Additionally, poor muscle quality was detected in 71% of patients among all age groups. Notably, there was a 95% agreement between AI and the RD’s assessment in detecting low muscle mass.

Conclusions: RDs can effectively analyze CT scans and use SMI and HU with their NFPE. The NFPE alone is not always sensitive enough to detect low muscle in surgical and critically ill patients. The degree of malnutrition dictates nutrition interventions, including the timing and type of nutrition support, so it is imperative to accurately diagnose and tailor interventions to improve outcomes.