Nutritional Risk at intensive care unit admission and outcomes in survivors of critical illness

Abstract

Background and aims: Risk factors for poor outcomes after critical illness are incompletely understood. While nutritional risk is associated with mortality in critically ill patients, its association with disability, cognitive, and health-related quality of life is unclear in survivors of critical illness. This study's objective was to determine whether greater nutritional risk at ICU admission is associated with greater disability, worse cognition, and worse HRQOL at 3 and 12-month follow-up.

Methods: We enrolled adults (≥18 years of age) with respiratory failure or shock treated in medical and surgical intensive care units from two U.S. centers. We measured nutritional risk using the modified Nutrition Risk in Critically Ill (mNUTRIC) score (range 0-9 [highest risk]) at intensive care unit admission. We measured associations between mNUTRIC scores and discharge destination, disability in basic activities of daily living (ADLs) using the Katz ADL, instrumental ADLs using the Functional Activities Questionnaire (FAQ), global cognition using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), executive function using the Trail Making Test Part B (Trails B), and health-related quality of life using the SF-36, adjusting for sex, education, BMI, baseline frailty, disability, and cognition, severity of illness, days of delirium, coma, and mechanical ventilation.

Results: Of the 821 patients enrolled in the ICU, 636 patients survived to hospital discharge. We assessed outcomes in 448 of 535 survivors (84%) at 3 months and 382 of 476 survivors (80%) at 12 months. Higher mNUTRIC scores predicted greater odds of discharge to an institution (OR 2.0, 95% CI: 1.6 to 2.6; P < 0.01). Higher mNUTRIC scores were associated with a trend towards greater disability in basic activities of daily living (IRR 1.3, 95% CI 1.0 to 1.7) at 3 months that did not reach significance (p = 0.09) with no association demonstrated at 12 months. There were no associations between mNUTRIC scores and FAQ, RBANS, or Trails B scores. mNUTRIC scores were inconsistently associated with SF-36 physical and mental component scale scores.

Conclusions: Greater nutritional risk at ICU admission is associated with disability in survivors of critical illness. Future studies should evaluate interventions in those at high nutritional risk as a means to speed recovery.

Keywords: Activities of daily living; Cognitive dysfunction; Critical illness; Nutrition assessment; Patient discharge; Quality of life.