Effect of neuromuscular electrical stimulation on functional exercise capacity in patients undergoing cardiac surgery: A randomized clinical trial

Abstract

Objective: To evaluate the effects of neuromuscular electrical stimulation on functional capacity of patients in the immediate postoperative period of cardiac surgery.

Design: A prospective, randomized controlled trial.

Setting: A cardiac surgery specialist hospital in Aracaju, Sergipe, Brazil. Subjects: Patients in the postoperative period of cardiac surgery.

Intervention: The control group received the conventional physiotherapy and the intervention group received neuromuscular electrical stimulation of the rectus femoris and gastrocnemius muscles bilaterally, applied for 60 min, twice a day for up to 10 sessions per patient, in the immediate postoperative period until postoperative day 5.

Main measures: The primary outcome was the distance walked, which was evaluated using the 6-min walk test on postoperative day 5. Secondary outcomes were gait speed, lactate levels, muscle strength, electromyographic activity of the rectus femoris and Functional Independence Measure, some of them evaluated on preoperative and postoperative period.

Results: Of 132 eligible patients, 88 patients were included and randomly allocated in two groups, and 45 patients were included in the analysis. No significant difference was found on the distance walked (p = 0.650) between patients allocated in intervention group (239.06 ± 88.55) and control group (254.43 ± 116.67) as well as gait speed (p = 0.363), lactate levels (p = 0.302), knee extensor strength (p = 0.117), handgrip strength (p = 0.882), global muscle strength (p = 0.104), electromyographic activity (p = 0.179) and Functional Independence Measure (p = 0.059).

Conclusions: Although the effects are still uncertain, the use of neuromuscular electrical stimulation carried out in five days didn't present any benefit on functional capacity of patients in the immediate postoperative period of cardiac surgery.

Keywords: Cardiac rehabilitation; ambulation; electric stimulation therapy; thoracic surgery.