Ambulation capacity and functional outcome in patients undergoing neuromuscular electrical stimulation after cardiac valve surgery: A randomised clinical trial

BACKGROUND: Early mobilization and physical exercise are considered fundamental components in cardiovascular surgery rehabilitation; however, occasionally they are inadequate for inhibiting functional decline. Neuromuscular electrical stimulation (NMES) is a promising tool in cardiovascular rehabilitation; however, to date, no randomized clinical trial has measured the effects of NMES on functional capacity and quality of life in patients who undergo routine cardiac surgery with a short intensive care unit (ICU) stay. Therefore, we aimed to investigate the effects of NMES on walking ability, muscle strength, functional independence, and quality of life in cardiac valve surgery patients in the immediate postoperative period. METHODS: A randomized, parallel, controlled, 2-arm clinical trial with assessor blinding was conducted. Fifty-nine adult patients in the preoperative period after cardiac valve reconstruction and/or replacement were randomly assigned to a control or intervention group. The intervention group underwent NMES in the quadriceps and gastrocnemius, bilaterally, for 60 minutes, for up to 10 sessions. The primary outcome was ambulation ability, assessed through the Six-Minute Walk Test and Walking Speed Test at postoperative day 5 (5PO). Secondary outcomes were muscular strength (assessed through the Medical Research Council scale), functional independence measure (assessed through the Functional Independence Measurement Questionnaire), and quality of life (assessed through the Nottingham Health Profile) at baseline (preoperative) and at postoperative days 3 and 5. RESULTS: The baseline characteristics were similar in both groups, except for body mass index. There was no statistically significant difference, with a small effect size, between both groups regarding the distance walked (95% CI, −64.87 to 65.97) and walking speed (95% CI, −0.55 to 0.57). There was a statistically significant difference in upper-limb muscle strength loss and decline in mobility at postoperative day 3, which had a tendency to recover to initial values at 5PO, in both groups. No significant between-group difference was noted for muscle strength, functional independence, and quality of life. CONCLUSIONS: The use of NMES had no effect on walking ability, strength, quality of life, or functional outcome in the postoperative period for patients that underwent regular valve replacement.