Nutrition assessment: the reproducibility of Subjective Global Assessment in patients requiring mechanical ventilation

BACKGROUND/OBJECTIVE: The detection of malnutrition in the intensive care unit (ICU) is critical to appropriately address its contribution on outcomes. The primary objective of this investigation was to determine if nutritional status could be reliably classified using Subjective Global Assessment (SGA) in mechanically ventilated (MV) patients. SUBJECTS/METHODS: Fifty-seven patients requiring MV greater than 48 hours in a university-affiliated medical ICU were evaluated in this cross-sectional study over a 3 month period. Nutritional status was categorized independently by two Registered Dietitians using SGA. Frequencies, means (± standard deviations), Chi square and T tests were used to describe the population characteristics; agreement between raters was evaluated using the κ statistic. RESULTS: On admission, the average patient was 50.4 (± 14.2) years of age, overweight (body mass index: 29.0 ± 9.2), had an APACHE II score of 24 (± 10) and respiratory failure. Fifty percent (n=29) of patients were categorized as malnourished. Agreement between raters was 95% prior to consensus, reflecting near perfect agreement (κ =0.90) and excellent reliability. Patients categorized as malnourished were more often admitted to the hospital floor prior to the ICU (n=32; 56%), reported decreased dietary intake (69% vs. 46%, p=0.02) and exhibited signs of muscle wasting (45% vs. 7%, p<0.001, respectively) and fat loss (52% vs. 7%, p<0.001, respectively) on physical exam when compared to normally nourished individuals. CONCLUSIONS: SGA can serve as a reliable nutrition assessment technique for detecting malnutrition in patients requiring MV. Its routine use should be incorporated into future studies and clinical practice.