Electrical Stimulation Improves Muscle Tone in Patients on Mechanical Ventilation

In patients receiving mechanical ventilation, muscle atrophy is reduced and muscle strength improved when neuromuscular electrical stimulation (NMES) is combined with early rehabilitation therapy, according to study findings published in BMC Pulmonary Medicine.

Researchers in China sought to evaluate the use of NMES combined with early rehabilitation to improve skeletal muscle and diaphragm tone in patients on mechanical ventilation (MV).

This prospective controlled study, conducted from February 2022 through September 2022, included 80 patients on MV for respiratory failure at the Affiliated Hospital of Qingdao University in China. Patients were randomly assigned to the study group (n=40; mean, 58 years of age; 37.5% women), which received NMES and early rehabilitation, or to a control group (n=40; mean 59 years of age; 42.5% women), which received early rehabilitation only. Patients were all expected to need MV for more than 72 hours. Those with preexisting neuromuscular lesions or unrelieved pneumothorax and restricted diaphragm movement disorders were excluded from the study.

Relevant ultrasound measurements were taken before and after intervention at the first day of MV, at the third and seventh day of intervention, and at day of discharge from the intensive care unit (ICU).

No significant between-group demographic differences or ultrasound indicators were found before rehabilitation (all P >.05).

The researchers found the variation of diaphragmatic thickening fraction (DTF) in the study group vs the control group on the day of ICU discharge was significantly higher (mean [SD] 0.15 [0.05%] vs 0.12 [0.04%]; P =.034). The variation was significantly lower in the study group vs the control group in the thickness of rectus abdominis (TRA; 0.05 [0.09%] vs 0.10 [0.11%]; P =.029), and in the cross-sectional area of rectus femoris (CSA-RF; 0.13 [0.07%] vs 0.19 [0.08%]; P <.001).

The study group vs control group had a significantly shorter duration of MV (median [interquartile range], 109.5 [88.0-213.0] hours vs 189.5 [131.5-343.5] hours; P =.023). The researchers noted better muscle strength score in the study group vs control group at discharge (mean [SD], 52.20 [11.70] vs 44.10 [15.70]; P =.011). No significant between-group difference was seen in duration of intubation. Adverse effects were noted in 4 patients in the study group.

Study limitations include the underpowered sample size and single-center design.

“NMES may be beneficial in slowing muscle atrophy and improving muscle strength at discharge in MV patients when combined with early rehabilitation therapy,” the researchers concluded. They added, “Although this intervention may require prolonged use for benefits, it can be used as an alternative and supplement to routine rehabilitation.”