Neuromuscular electrical stimulation may attenuate muscle proteolysis after cardiovascular surgery: A preliminary study

Neuromuscular electrical stimulation, muscle mass, and physical function decline in the early phase after living donor liver transplantation

This study aims to investigate the effects of neuromuscular electrical stimulation (NMES) in addition to conventional early mobilization in the early postoperative period after living donor liver transplantation (LTx) on body composition and physical function. This was a retrospective single-center cohort study. Adult subjects who were admitted for living donor LTx from 2018 to 2023 were included in the analysis. After April 2020, patients underwent 4 weeks of NMES in addition to conventional rehabilitation. The skeletal muscle mass index, body cell mass, and physical function, including the 6-minute walking distance, were assessed before surgery and at discharge, and changes in these outcomes were compared before and after the introduction of NMES. Sixty-one patients were in the NMES group, and 53 patients before the introduction of NMES were in the control group. ANCOVA with etiology, obstructive ventilatory impairment, Child-Pugh classification, and initial body composition value as covariates demonstrated that there was a significantly smaller decline of body cell mass (-2.9±2.7 kg vs. -4.4±2.7 kg, p = 0.01), as well as of the skeletal muscle mass index (-0.78±0.73 kg/m2 vs. -1.29±1.21 kg/m2, p = 0.04), from baseline to discharge in the NMES group than in the control group; thus, the decline after surgery was suppressed in the NMES group. Four weeks of NMES, in addition to conventional rehabilitation in the early period after LTx, may attenuate the deterioration of muscle mass. It is suggested that NMES is an option for developing optimized rehabilitation programs in the acute postoperative period after LTx.

Effects of acute phase intensive electrical muscle stimulation in COVID-19 patients requiring invasive mechanical ventilation: an observational case-control study

We investigated the effects of acute-phase intensive electrical muscle stimulation (EMS) on physical function in COVID-19 patients with respiratory failure requiring invasive mechanical ventilation (IMV) in the intensive care unit (ICU). Consecutive COVID-19 patients requiring IMV admitted to a university hospital ICU between January and April 2022 (EMS therapy group) or between March and September 2021 (age-matched historical control group) were included in this retrospective observational case-control study. EMS was applied to both upper and lower limb muscles for up to 2 weeks in the EMS therapy group. The study population consisted of 16 patients undergoing EMS therapy and 16 age-matched historical controls (median age, 71 years; 81.2% male). The mean period until initiation of EMS therapy after ICU admission was 3.2 ± 1.4 days. The EMS therapy group completed a mean of 6.2 ± 3.7 EMS sessions, and no adverse events occurred. There were no significant differences between the two groups in Medical Research Council sum score (51 vs. 53 points, respectively; P = 0.439) or ICU mobility scale at ICU discharge. Addition of upper and lower limb muscle EMS therapy to an early rehabilitation program did not result in improved physical function at ICU discharge in severe COVID-19 patients.

Ultrasound assessment of muscle mass and correlation with clinical outcomes in critically ill patients: a prospective observational study

PURPOSE

Muscular atrophy implies structural and functional alterations related to muscular force production and movement. This condition has been reported to be the main reason for generalized muscle weakness; it reflects the severity of the disease and can have a profound impact on short- and long-term clinical outcomes. The purpose of this study was to determine whether muscle atrophy ultrasound parameters early predict muscle weakness, morbidity, or 28-days mortality.

METHODS

This was a prospective, observational single center cohort study. Ultrasound was used to determine the cross-sectional area and muscle thickness of the rectus femoris on the first and third day of ICU stay. The main outcome was the incidence of significant muscle atrophy (≥ 10%).

RESULTS

Ultrasound measurements were made in 31 patients, 58% (18/31) of which showed significant muscle atrophy. The relative loss of muscle mass per day was 1.78 at 5% per day. The presence of muscle atrophy presents increased risk for limb muscle weakness and handgrip weakness. The 28-days mortality rate was similar in both subgroups.

CONCLUSION

The presence of muscle atrophy presents an increased clinical risk for the development of limb ICUAW and handgrip, although these observations were not statistically significant. The results could be used to plan future studies on this topic.

Efficacy of neuromuscular electrical stimulation for thoracic and abdominal surgery: A systematic review and meta-analysis

This systematic review and meta-analysis examined the efficacy of neuromuscular electrical stimulation (NMES) on lower limb muscle strength and health-related quality of life (HR-QOL) after thoracic and abdominal surgery. We searched the Cochrane Central Register of Controlled Trials, MEDLINE via PubMed, Excerpta Medica Database via Elsevier, Physiotherapy Evidence Database, Cumulative Index to Nursing and Allied Health Literature, World Health Organization International Clinical Trials Registry Platform via their dedicated search portal, and ClinicalTrials.gov on November 2021 and updated in April 2023 to identify randomized controlled trials that examined the effects of NMES after thoracic and abdominal surgery. The primary outcomes were lower limb muscle strength, HR-QOL, and adverse events. We used the Cochrane Risk of Bias Tool and the Grading of Recommendations, Assessment, Development, and Evaluation approach to assess the certainty of evidence. A total of 18 randomized control trials involving 915 participants, including 10 on cardiovascular surgery, two on pulmonary surgery, five on digestive system surgery, and one on other surgery, were included. NMES slightly increased lower limb muscle strength and adverse events in cardiovascular surgery. Adverse events (hypotension, pain, and muscle discomfort) occurred in seven patients. HR-QOL was measured in two studies on cardiovascular surgery, but these were not pooled due to concept heterogeneity. Overall, NMES slightly increases lower limb muscle strength after cardiovascular surgery without serious adverse events. However, higher-quality randomized control trials in thoracic and abdominal surgeries are needed.

Factors associated with postsurgical muscle weakness in patients who undergo thoracic aortic surgery: a retrospective cohort study

OBJECTIVE

Aortic surgery is often performed in elderly patients, and these patients have a high risk of postsurgical muscle weakness. To reinforce purposeful postsurgical rehabilitation, we aimed to investigate the factors associated with postsurgical muscle weakness in patients who underwent thoracic aortic surgery.

METHODS

This retrospective cohort study analyzed data of consecutive patients who underwent elective thoracic aortic surgery with cardiopulmonary bypass, and whose knee extensor isometric muscle strength (KEIS) were measured pre- and postoperatively at University Hospital between January 2012 and December 2018. The primary outcome was percent change in KEIS (% change in KEIS). Multivariate linear regression analysis was used to identify independent risk factors for % change in KEIS.

RESULTS

Overall, 218 patients were included. Multivariate linear regression analysis showed that mechanical ventilation time, days from initial sitting to 100 m walking, and the number of exercises in the rehabilitation room were associated with % change in KEIS.

CONCLUSIONS

This study may serve as a reference to stratify patients at risk of postsurgical muscle weakness. The preventive or alternative interventions in patients undergoing thoracic aortic surgery will be assessed in future studies.

Cognitive outcomes in patients treated with neuromuscular electrical stimulation after coronary artery bypass grafting

Objective

Mechanisms of neurocognitive injury as post-operative sequelae of coronary artery bypass grafting (CABG) are not understood. The systemic inflammatory response to surgical stress causes skeletal muscle impairment, and this is also worsened by immobility. Since evidence supports a link between muscle vitality and neuroprotection, there is a need to understand the mechanisms by which promotion of muscle activity counteracts the deleterious effects of surgery on long-term cognition.

Methods

We performed a clinical trial to test the hypothesis that adding neuromuscular electrical stimulation (NMES) to standard rehabilitation care in post-CABG patients promotes the maintenance of skeletal muscle strength and the expression of circulating neuroprotective myokines.

Results

We did not find higher serum levels of neuroprotective myokines, except for interleukin-6, nor better long-term cognitive performance in our intervention group. However, a greater increase in functional connectivity at brain magnetic resonance was seen between seed regions within the default mode, frontoparietal, salience, and sensorimotor networks in the NMES group. Regardless of the treatment protocol, patients with a Klotho increase 3 months after hospital discharge compared to baseline Klotho values showed better scores in delayed memory tests.

Significance

We confirm the potential neuroprotective effect of Klotho in a clinical setting and for the first time post-CABG.

Skeletal muscle adaptation to indirect electrical stimulation: divergence between microvascular and metabolic adaptations

NEW FINDINGS

What is the central question of this study? Can we manipulate muscle recruitment to differentially enhance skeletal muscle fatigue resistance? What is the main finding and its importance? Through manipulation of muscle activation patterns, it is possible to promote distinct microvascular growth. Enhancement of fatigue resistance is closely associated with the distribution of the capillaries within the muscle, not necessarily with quantity. Additionally, at the acute stages of remodelling in response to indirect electrical stimulation, the improvement in fatigue resistance appears to be primarily driven by vascular remodelling, with metabolic adaptation of secondary importance.

ABSTRACT

Exercise involves a complex interaction of factors influencing muscle performance, where variations in recruitment pattern (e.g., endurance vs. resistance training) may differentially modulate the local tissue environment (i.e., oxygenation, blood flow, fuel utilization). These exercise stimuli are potent drivers of vascular and metabolic change. However, their relative contribution to adaptive remodelling of skeletal muscle and subsequent performance is unclear. Using implantable devices, indirect electrical stimulation (ES) of locomotor muscles of rat at different pacing frequencies (4, 10 and 40 Hz) was used to differentially recruit hindlimb blood flow and modulate fuel utilization. After 7 days, ES promoted significant remodelling of microvascular composition, increasing capillary density in the cortex of the tibialis anterior by 73%, 110% and 55% for the 4 Hz, 10 and 40 Hz groups, respectively. Additionally, there was remodelling of the whole muscle metabolome, including significantly elevated amino acid turnover, with muscle kynurenic acid levels doubled by pacing at 10 Hz (P < 0.05). Interestingly, the fatigue index of skeletal muscle was only significantly elevated in 10 Hz (58% increase) and 40 Hz (73% increase) ES groups, apparently linked to improved capillary distribution. These data demonstrate that manipulation of muscle recruitment pattern may be used to differentially expand the capillary network prior to altering the metabolome, emphasising the importance of local capillary supply in promoting exercise tolerance.

Prehabilitation in Cardiovascular Surgery: The Effect of Neuromuscular Electrical Stimulation (Randomized Clinical Trial)

OBJECTIVE

We aimed to determine the effects of prehabilitation with neuromuscular electrical stimulation (NMES) on muscle status and exercise capacity in patients before cardiac surgery.

METHODS

Preoperative elective cardiac surgery patients were randomly assigned to the NMES group or control group. Intervention in the NMES group was 7-10 sessions, whereas the control group carried out breathing exercises and an educational program. The outcome measures included a six-minute walk test (6MWT) and a muscle status assessment (knee extensor strength (KES), knee flexor strength (KFS), and handgrip strength (HS)) after the course of prehabilitation.

RESULTS

A total of 122 patients (NMES, n = 62; control, n = 60) completed the study. During the NMES course, no complications occurred. After the course prehabilitation KES, KFS, and 6MWT distance were significantly increased (all p < 0.001) in the NMES group compared to the control. There was no significant difference in HS before surgery.

CONCLUSIONS

A short-term NMES course before cardiac surgery is feasible, safe, and effective to improve preoperative functional capacity (six-minute walk distance) and the strength of stimulated muscles.

Neuromuscular electrical stimulation after cardiovascular surgery mitigates muscle weakness in older individuals with diabetes

BACKGROUND

Cardiovascular surgery leads to postsurgical muscle weakness, probably because of muscle proteolysis and peripheral nerve dysfunction, which are augmented by aging and diabetes mellitus.

OBJECTIVE

We examined the effect of neuromuscular electrical stimulation (NMES) on postsurgical muscle weakness in older individuals with diabetes mellitus.

METHODS

We conducted a multicentre, randomized, controlled trial, and screened consecutive patients with diabetes who underwent cardiovascular surgery for eligibility (age ≥ 65 years). Those included were randomly assigned to the NMES or the sham group. The primary outcome was the percent change in isometric knee extension strength (%ΔIKES) from preoperative to postoperative day 7. Secondary outcomes were the percent change in usual (%ΔUWS), maximum walking speed (%ΔMWS), and grip strength (%ΔGS). A statistician who was blinded to group allocation used intention-to-treat analysis (student t test).

RESULTS

Of 1151 participants screened for eligibility, 180 (NMES, n = 90; sham, n = 90) were included in the primary analysis. %ΔIKES was significantly lower in the NMES than sham group (NMES: mean -2%, 95% confidence interval [CI] -6 to 1; sham: -13%, 95% CI -17 to -9, p < 0.001). Among the secondary outcomes, %ΔMWS was significantly lower and %ΔUWS and %ΔGS were lower, although not significantly, in the NMES than sham group.

CONCLUSIONS

A short course of NMES (< 1 week) mitigated postsurgical muscle weakness and functional decline in older persons with diabetes mellitus. NMES could be recommended as a part of postsurgical rehabilitation in older people with diabetes mellitus, especially those with a low functional reserve.

Neuromuscular electrical stimulation in the intensive care unit prevents muscle atrophy in critically ill older patients: A retrospective cohort study

Critically ill patients in the intensive care unit (ICU) develop muscle atrophy and decreased physical function. Though neuromuscular electrical stimulation (NMES) therapy has been shown to be effective in preventing this, but its effect on older patients is unknown. To examine the course of critically ill older patients treated with NMES in the ICU and to define the impact of its use. A retrospective cohort study was conducted using older ICU patients (≥65 years) categorized into a control group (n = 20) and an NMES group (n = 22). For subgroup analysis, each group was further classified into pre-old age (65-74 years) and old age (≥75 years). The control group showed significant decrease in muscle thickness during ICU and hospital stay. The NMES group showed lower reduction in muscle thickness and showed decrease in muscle echo intensity during hospital stay, compared to the control group. NMES inhibited decrease in muscle thickness in the pre-old age group versus the old age group. The decreasing effect of NMES on echo intensity during hospital stay manifested only in the pre-old age group. We did not find much difference in physical functioning between the NMES and control groups. Lower limb muscle atrophy reduces in critically ill older patients (≥65 years) with NMES and is pronounced in patients aged < 75 years. The impact of NMES on the physical functioning of older patients in ICU needs to be further investigated.

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

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.

Effects of neuromuscular electrical stimulation on functional capacity and quality of life among patients after cardiac surgery: A systematic review and meta-analysis

BACKGROUND

Neuromuscular electrical stimulation (NMES) is a possible adjunctive therapy applied to cardiac surgery patients to improve physical function, but the results are still controversial. A systematic review and meta-analysis was conducted to investigate the effects of NMES on functional capacity and quality of life (QoL) in cardiac surgery patients.

METHODS

The following databases PubMed, Embase, Medicine, CINAHL, and the Cochrane Central Register of Controlled Trials were searched for the English language from inception up to March 2021. A systematic targeted literature search evaluating the effects of NMES on physical function and QoL in cardiac surgery patients. The effect size of NMES was presented as the mean difference (MD)/standardized mean difference (SMD) and its 95% confidence interval using fixed/random effect models according to heterogeneity. Two reviewers independently screened and appraised each study by using the Cochrane Risk of Bias Tool.

RESULTS

Six studies were included involving 400 cardiac surgery patients. The meta-analysis showed that NMES had effect on knee extensor strength (SMD=1.68; p=0.05), but had no effects on 6-minute walking distance (MD=44.08; p=0.22), walking speed (MD=0.05; p=0.24), grip strength (MD=3.01; p=0.39), or QoL (SMD=0.53; p=0.19).

CONCLUSIONS

NMES use in cardiac surgery patients is limited by low to moderate quality. Existing evidence shows that NMES is safe and effective for improving knee extensor strength.

Effect of Electrical Muscle Stimulation on Upper and Lower Limb Muscles in Critically Ill Patients: A Two-Center Randomized Controlled Trial

OBJECTIVES

Electrical muscle stimulation is widely used to enhance lower limb mobilization. Although upper limb muscle atrophy is common in critically ill patients, electrical muscle stimulation application for the upper limbs has been rarely reported. The purpose of this study was to investigate whether electrical muscle stimulation prevents upper and lower limb muscle atrophy and improves physical function.

DESIGN

Randomized controlled trial.

SETTING

Two-center, mixed medical/surgical ICU.

PATIENTS

Adult patients who were expected to be mechanically ventilated for greater than 48 hours and stay in the ICU for greater than 5 days.

INTERVENTIONS

Forty-two patients were randomly assigned to the electrical muscle stimulation (n = 17) or control group (n = 19).

MEASUREMENTS AND MAIN RESULTS

Primary outcomes were change in muscle thickness and cross-sectional area of the biceps brachii and rectus femoris from day 1 to 5. Secondary outcomes included occurrence of ICU-acquired weakness, ICU mobility scale, length of hospitalization, and amino acid levels. The change in biceps brachii muscle thickness was -1.9% versus -11.2% in the electrical muscle stimulation and control (p = 0.007) groups, and the change in cross-sectional area was -2.7% versus -10.0% (p = 0.03). The change in rectus femoris muscle thickness was -0.9% versus -14.7% (p = 0.003) and cross-sectional area was -1.7% versus -10.4% (p = 0.04). No significant difference was found in ICU-acquired weakness (13% vs 40%; p = 0.20) and ICU mobility scale (3 vs 2; p = 0.42) between the groups. The length of hospitalization was shorter in the electrical muscle stimulation group (23 d [19-34 d] vs 40 d [26-64 d]) (p = 0.04). On day 3, the change in the branched-chain amino acid level was lower in the electrical muscle stimulation group (40.5% vs 71.5%; p = 0.04).

CONCLUSIONS

In critically ill patients, electrical muscle stimulation prevented upper and lower limb muscle atrophy and attenuated proteolysis and decreased the length of hospitalization.

Neuromuscular electrical stimulation in early rehabilitation of patients with postoperative complications after cardiovascular surgery: A randomized controlled trial

BACKGROUND

To evaluate the effectiveness of neuromuscular electrical stimulation (NMES) in early rehabilitation of patients with postoperative complications after cardiovascular surgery.

METHODS

37 patients (25 men and 12 women) aged 45 to 70 years with postoperative complications after cardiovascular surgery were included in the study. Eighteen patients underwent NMES daily since postoperative day 3 until discharge in addition to standard rehabilitation program (NMES group), and 19 patients underwent standard rehabilitation program only (non-NMES group). The primary outcome was the knee extensors strength at discharge in NMES group and in control. Secondary outcomes were the handgrip strength, knee flexor strength, and cross-sectional area (CSA) of the quadriceps femoris in groups at discharge.

RESULTS

Baseline characteristics were not different between the groups. Knee extensors strength at discharge was significantly higher in the NMES group (28.1 [23.8; 36.2] kg on the right and 27.45 [22.3; 33.1] kg on the left) than in the non-NMES group (22.3 [20.1; 27.1] and 22.5 [20.1; 25.9] kg, respectively; P < .001). Handgrip strength, knee flexor strength, quadriceps CSA, and 6 minute walk distance at discharge in the groups had no significant difference.

CONCLUSIONS

This pilot study shows a beneficial effect of NMES on muscle strength in patients with complications after cardiovascular surgery. The use of NMES showed no effect on strength of non-stimulated muscle, quadriceps CSA, and distance of 6-minute walk test at discharge.Further blind randomized controlled trials should be performed with emphasis on the effectiveness of NEMS in increasing muscle strength and structure in these patients.

Effect of Perioperative Neuromuscular Electrical Stimulation in Patients Undergoing Cardiovascular Surgery: A Pilot Randomized Controlled Trial

A randomized, controlled trial was conducted to examine the effects of perioperative neuromuscular electrical stimulation on muscle proteolysis and physical function using blinded assessment of physical function. Consecutive patients undergoing cardiovascular surgery were screened for eligibility as study subjects. Participants were randomly assigned to receive either neuromuscular electrical stimulation or the usual postoperative mobilization program. The intervention group received neuromuscular electrical stimulation on bilateral legs 8 times before and after surgery. The primary outcomes were the mean 3-methylhistidine concentration corrected for urinary creatinine content from baseline to postoperative day 6, and knee extensor isometric muscle strength on postoperative day 7. Secondary outcomes were usual walking speed and grip strength. Physical therapists blinded to patient allocation performed measurements of physical function. Of 498 consecutive patients screened for eligibility, 119 participants (intervention group, n = 60; control group, n = 59) were enrolled. In the overall subjects, there were no differences in any outcomes between the intervention and control groups. The results demonstrated no significant effects of neuromuscular electrical stimulation on muscle proteolysis and physical function after cardiovascular surgery, suggesting the need to explore indications for neuromuscular electrical stimulation and to clarify the effects in terms of the dose-response relationship.

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.