Effect of In-Bed Leg Cycling and Electrical Stimulation of the Quadriceps on Global Muscle Strength in Critically Ill Adults: A Randomized Clinical Trial

Abstract

Importance: Early in-bed cycling and electrical muscle stimulation may improve the benefits of rehabilitation in patients in the intensive care unit (ICU).

Objective: To investigate whether early in-bed leg cycling plus electrical stimulation of the quadriceps muscles added to standardized early rehabilitation would result in greater muscle strength at discharge from the ICU.

Design, setting, and participants: Single-center, randomized clinical trial enrolling critically ill adult patients at 1 ICU within an 1100-bed hospital in France. Enrollment lasted from July 2014 to June 2016 and there was a 6-month follow-up, which ended on November 24, 2016.

Interventions: Patients were randomized to early in-bed leg cycling plus electrical stimulation of the quadriceps muscles added to standardized early rehabilitation (n = 159) or standardized early rehabilitation alone (usual care) (n = 155).

Main outcomes and measures: The primary outcome was muscle strength at discharge from the ICU assessed by physiotherapists blinded to treatment group using the Medical Research Council grading system (score range, 0-60 points; a higher score reflects better muscle strength; minimal clinically important difference of 4 points). Secondary outcomes at ICU discharge included the number of ventilator-free days and ICU Mobility Scale score (range, 0-10; a higher score reflects better walking capability). Functional autonomy and health-related quality of life were assessed at 6 months.

Results: Among 314 randomized patients, 312 (mean age, 66 years; women, 36%; receiving mechanical ventilation at study inclusion, 78%) completed the study and were included in the analysis. The median global Medical Research Council score at ICU discharge was 48 (interquartile range [IQR], 29 to 58) in the intervention group and 51 (IQR, 37 to 58) in the usual care group (median difference, -3.0 [95% CI, -7.0 to 2.8]; P = .28). The ICU Mobility Scale score at ICU discharge was 6 (IQR, 3 to 9) in both groups (median difference, 0 [95% CI, -1 to 2]; P = .52). The median number of ventilator-free days at day 28 was 21 (IQR, 6 to 25) in the intervention group and 22 (IQR, 10 to 25) in the usual care group (median difference, 1 [95% CI, -2 to 3]; P = .24). Clinically significant events occurred during mobilization sessions in 7 patients (4.4%) in the intervention group and in 9 patients (5.8%) in the usual care group. There were no significant between-group differences in the outcomes assessed at 6 months.

Conclusions and relevance: In this single-center randomized clinical trial involving patients admitted to the ICU, adding early in-bed leg cycling exercises and electrical stimulation of the quadriceps muscles to a standardized early rehabilitation program did not improve global muscle strength at discharge from the ICU.

Trial registration: ClinicalTrials.gov Identifier: NCT02185989.

Conflict of interest statement

Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Barbier reported receiving personal fees from Merck Sharp & Dohme. No other disclosures were reported.

Figures

Figure 1.. Flow of Patients Through the Study

ICU indicates intensive care unit. aThere were 49 patients who had a cardiac arrest during the screening period and it was the reason for hospital admission in 118 patients. bThere were 31 patients with severe traumatic brain injury, 51 with status epilepticus, 21 with ischemic stroke, 27 with hemorrhagic stroke, and 21 with other causes. cThere were 4 patients who were transferred to another hospital for emergency cardiac surgery. One patient was overlooked by study investigators. dTwo patients were transferred to another hospital (one for emergency cardiac surgery and the other for emergency liver transplantation). One patient died within 24 hours after discharge from the ICU before an assessment could be performed. Two patients were overlooked by study investigators.

Figure 2.. Box Plots of Medical Research Council Muscle Strength Score by Randomization Group

ICU indicates intensive care unit. In these box-and-whisker plots, the middle vertical line represents the median; the horizontal lines extend from the minimum to the maximum value, excluding outside values, which are displayed as separate open circle points. The outside values are smaller than the lower quartile minus 1.5 times the interquartile range or are larger than the upper quartile plus 1.5 times the interquartile range. The Medical Research Council (MRC) score reflects the strength of the muscle groups used to mobilize joints on both sides of the body from 0 (no visible contraction) to 5 (normal strength). The joint motions examined were shoulder abduction, elbow flexion, wrist extension, hip flexion, knee extension, and ankle dorsiflexion. The overall score range is from 0 to 60. This graph excludes 5 surviving patients in each group in whom the primary outcome could not be assessed. The patients who died in the ICU were assigned a value of 0 for the MRC score. The randomized intervention group × subgroup interaction was tested using the aligned rank transform test and no plausible interactions were found. The results of the comparisons between the intervention group and the usual care group within each subgroup appear in eTable 4 in Supplement 2.