Association between nutritional risk and ICU mortality

Abstract

Introduction

Critically ill patients are highly vulnerable to malnutrition, which has been associated with adverse outcomes. Nutritional risk assessment tools such as the modified Nutrition Risk in Critically Ill (mNUTRIC) score and the Subjective Global Assessment (SGA) are widely used, although their prognostic role relative to illness severity remains debated.

Methods

A prospective cohort study was conducted in a mixed adult intensive care unit. Adult patients (≥18 years) admitted to the ICU were included. Patients in the immediate postoperative period of scheduled surgery were excluded. Nutritional risk was assessed using mNUTRIC and SGA. The primary outcome was ICU mortality. Associations were evaluated using bivariate and multivariable analyses.

Results

A total of 180 patients were analyzed (mean age 51.3 ± 16.3 years; 60% male). ICU mortality was 30%. High nutritional risk by mNUTRIC was present in 23% of patients with CRP and was associated with higher unadjusted mortality (55% vs. 23%; p = 0.0014). Mortality also increased across SGA categories (p = 0.0091). In the fully adjusted model, mortality was independently associated with male sex (adjusted OR 2.58; 95% CI 1.13–5.85) and SOFA score (adjusted OR 1.28; 95% CI 1.10–1.49), while the association with high mNUTRIC was attenuated. The model showed acceptable discrimination (AUC 0.766).

Conclusions

Nutritional risk was strongly associated with ICU mortality in unadjusted analyses but did not remain an independent predictor after adjustment for organ dysfunction. Nutritional risk appears to function as a marker of vulnerability closely linked to disease severity rather than as a causal determinant of mortality.