Impact of ICU-acquired weakness on post-ICU physical functioning: a follow-up study

Crit Care. 2015 Apr 27;19(1):196. doi: 10.1186/s13054-015-0937-2.


Introduction: ICU-acquired weakness is thought to mediate physical impairments in survivors of critical illness, but few studies have investigated this thoroughly. The purpose was to investigate differences in post-ICU mortality and physical functioning between patients with and without ICU-acquired weakness at 6 months after ICU discharge.

Method: ICU patients, mechanically ventilated ≥ 2 days, were included in a single-center prospective observational cohort study. ICU-acquired weakness was diagnosed when the average Medical Research Council score was <4 in awake and attentive patients. Post-ICU mortality was recorded until 6 months after ICU discharge; in surviving patients, physical functioning was assessed using the Short-Form Health Survey physical functioning domain. The independent effect of ICU-acquired weakness on post-ICU mortality was analyzed using a multivariable Cox proportional hazards model. The independent effect of ICU-acquired weakness on the physical functioning domain score was analyzed using a multivariable linear regression model.

Results: Of the 156 patients included, 80 had ICU-acquired weakness. Twenty-three patients died in the ICU (20 with ICU-acquired weakness); during 6 months follow-up after ICU discharge another 25 patients died (17 with ICU-acquired weakness). Physical functioning domain scores were available for 96 survivors (39 patients with ICU-acquired weakness). ICU-acquired weakness was independently associated with an increase in post-ICU mortality (hazard ratio 3.6, 95% confidence interval, 1.3 to 9.8; P = 0.01) and with a decrease in physical functioning (β: -16.7 points; 95% confidence interval, -30.2 to -3.1; P = 0.02).

Conclusion: ICU-acquired weakness is independently associated with higher post-ICU mortality and with clinically relevant lower physical functioning in survivors at 6 months after ICU discharge.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cohort Studies
  • Critical Illness / mortality*
  • Critical Illness / therapy
  • Female
  • Follow-Up Studies
  • Humans
  • Intensive Care Units / trends*
  • Male
  • Middle Aged
  • Muscle Weakness / complications
  • Muscle Weakness / diagnosis
  • Muscle Weakness / mortality*
  • Patient Discharge / trends*
  • Prospective Studies
  • Recovery of Function*
  • Respiration, Artificial / adverse effects
  • Respiration, Artificial / mortality
  • Respiration, Artificial / trends
  • Survival Rate / trends