Acute Outcomes and 1-Year Mortality of Intensive Care Unit–acquired Weakness. A Cohort Study and Propensity-matched Analysis

TLDR

Intensive care unit–acquired weakness is a frequent complication of critical illness. The study aimed to determine the acute outcomes, 1‑year mortality, and costs associated with ICU‑acquired weakness in long‑stay ICU patients and to evaluate the effect of recovery of weakness at ICU discharge. Prospective data from a randomized controlled trial were analyzed using one‑to‑one propensity‑score matching and multivariable Cox proportional hazards models to assess the impact of weakness on outcomes. Weak patients had lower rates of successful weaning, ICU and hospital discharge, higher in‑hospital costs, and a 1‑year mortality of 30.6% versus 17.2% in matched controls, with persistence and greater severity of weakness further increasing mortality. Clinical trial registered at www.clinicaltrials.gov (NCT 00512122).

Abstract

Intensive care unit (ICU)-acquired weakness is a frequent complication of critical illness. It is unclear whether it is a marker or mediator of poor outcomes.To determine acute outcomes, 1-year mortality, and costs of ICU-acquired weakness among long-stay (≥8 d) ICU patients and to assess the impact of recovery of weakness at ICU discharge.Data were prospectively collected during a randomized controlled trial. Impact of weakness on outcomes and costs was analyzed with a one-to-one propensity-score-matching for baseline characteristics, illness severity, and risk factor exposure before assessment. Among weak patients, impact of persistent weakness at ICU discharge on risk of death after 1 year was examined with multivariable Cox proportional hazards analysis.A total of 78.6% were admitted to the surgical ICU; 227 of 415 (55%) long-stay assessable ICU patients were weak; 122 weak patients were matched to 122 not-weak patients. As compared with matched not-weak patients, weak patients had a lower likelihood for live weaning from mechanical ventilation (hazard ratio [HR], 0.709 [0.549-0.888]; P = 0.009), live ICU (HR, 0.698 [0.553-0.861]; P = 0.008) and hospital discharge (HR, 0.680 [0.514-0.871]; P = 0.007). In-hospital costs per patient (+30.5%, +5,443 Euro per patient; P = 0.04) and 1-year mortality (30.6% vs. 17.2%; P = 0.015) were also higher. The 105 of 227 (46%) weak patients not matchable to not-weak patients had even worse prognosis and higher costs. The 1-year risk of death was further increased if weakness persisted and was more severe as compared with recovery of weakness at ICU discharge (P < 0.001).After careful matching the data suggest that ICU-acquired weakness worsens acute morbidity and increases healthcare-related costs and 1-year mortality. Persistence and severity of weakness at ICU discharge further increased 1-year mortality. Clinical trial registered with www.clinicaltrials.gov (NCT 00512122).