Variables associated with mobility levels in critically ill patients: A cohort study

Background: Early mobilization in the intensive care unit (ICU) helps improve patients' functional status at discharge. However, many barriers hinder this practice. Aim and objectives: To identify mobility levels acquired by critically ill patients and their variables. Design: A multi-centre cohort study was conducted in adult patients receiving invasive mechanical ventilation for at least 48 hours. Methods: The primary outcome was level of mobility according to the ICU mobility scale. The secondary outcome was human resource availability and existence of ABCDEF bundle guidelines. A logistic regression was performed, based on days 3 to 5 of the ICU stay and significant association with active mobility. Results: Six hundred and forty-two patients were included from 80 ICUs. Active moving in and out of bed was found on 9.9% of patient-days from day 8 of the ICU stay. Bed exercises, or passive transfers, and immobility were observed on 45.6% and 42.2% of patient-days, respectively. Patients achieving active mobility (189/642, 29.4%) were in ICUs with more physiotherapist hours. Active mobility was more likely with a 1:4 nurse-patient ratio (odds ratio [OR] 3.7 95% confidence interval [CI] [1.2-11.2]), high MRC sum-score (OR 1.05 95% CI [1.04-1.06]) and presence of delirium (OR 1.01 95% CI [1.00-1.02]). By contrast, active mobility was hindered by higher BMI (OR 0.92 95% CI [0.88-0.97]), a 1:3 nurse-patient ratio (OR 0.54 95% CI [0.32-0.93]), or a shift-dependent nurse-patient ratio (OR 0.27 95% CI [0.12-0.62]). Conclusions: Immobility and passive mobilization were prevalent. A high MRC sumscore and presence of delirium are protective factors of mobilization. A 1:4 nursepatient ratio shows a stronger association with active mobility than a 1:3 ratio. Relevance to clinical practice: Severity-criteria-based nurse-patient ratios hinder mobilization. Active mobilization may be enhanced by using nursing-interventionbased ratios, increasing physiotherapist hours, and achieving wider application of the ABCDEF bundle, resulting in more awake, cooperative patients