Care and treatments related to intensive care unit-acquired muscle weakness: A cohort study

Aust Crit Care. 2021 Sep;34(5):435-445. doi: 10.1016/j.aucc.2020.12.005. Epub 2021 Mar 2.


Background: Intensive care unit-acquired muscle weakness (ICUAW) has an incidence of 40-46%. Early mobilisation is known to be a protective factor.

Objective: The aim of the study was to identify the incidence of ICUAW in Spain and to evaluate variables likely to contribute to the development of ICUAW.

Methods: A 4-month, prospective observational multicentre cohort study was conducted on patients receiving invasive mechanical ventilation for at least 48 h. Data were collected from ICU day 3 until ICU discharge. The primary outcome was presence of ICUAW (diagnosed using the Medical Research Council [MRC] scale). The secondary outcome was nurse-patient ratio, physiotherapist availability, analgesia, sedation and delirium management, glycaemic control, and daily level of mobility during the ICU stay as per the ICU Mobility Scale. A logistic regression model was constructed based exclusively on days 3-5 of the ICU stay.

Results: The data of 642 patients were analysed from 80 ICUs, accounting for 35% of all ICUs in Spain. The incidence of ICUAW was 58% (275 of 474 patients; 95% confidence interval [CI] [53-62]). The predictors for ICUAW were older age (odds ratio [OR] = 1.01; 95% CI [1.00-1.03]) and more days with renal replacement therapy (OR = 1.01; 95% CI [1.00-1.02]). The protective factors for ICUAW were male gender (OR = 0.58; 95% CI [0.38-0.89]), higher Barthel Index (showing prehospital functional independence) (OR = 0.97; 95% CI [0.95-0.99]), more days of being awake and cooperative (defined by a feasible MRC assessment) (OR = 0.98; 95% CI [0.97-0.99]), presence of delirium (OR = 0.98; 95% CI [0.97-0.99]), and more days with active mobilisation (ICU Mobility Scale ≥ 4) (OR = 0.98; 95% CI [0.97-0.99]).

Conclusions: The risk factors for ICUAW were functional dependence before admission, female gender, older age, and more days on renal replacement therapy. The protective factors for ICUAW were feasibility of MRC assessment, the presence of delirium, and being actively mobilised during the first 5 days in the ICU.

Keywords: Critical care nursing; Early mobilisation; Physical therapy; Physiotherapy; Sedation; Weakness.

Publication types

  • Observational Study

MeSH terms

  • Aged
  • Cohort Studies
  • Female
  • Humans
  • Intensive Care Units*
  • Length of Stay
  • Male
  • Muscle Weakness* / epidemiology
  • Respiration, Artificial