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

Safety and effectiveness of neuromuscular electrical stimulation in cardiac surgery: A systematic review

BACKGROUND

Lack of mobilization and prolonged stay in the intensive care unit (ICU) are major factors resulting in the development of ICU-acquired muscle weakness (ICUAW). ICUAW is a type of skeletal muscle dysfunction and a common complication of patients after cardiac surgery, and may be a risk factor for prolonged duration of mechanical ventilation, associated with a higher risk of readmission and higher mortality. Early mobilization in the ICU after cardiac surgery has been found to be low with a significant trend to increase over ICU stay and is also associated with a reduced duration of mechanical ventilation and ICU length of stay. Neuromuscular electrical stimulation (NMES) is an alternative modality of exercise in patients with muscle weakness. A major advantage of NMES is that it can be applied even in sedated patients in the ICU, a fact that might enhance early mobilization in these patients.

AIM

To evaluate safety, feasibility and effectiveness of NMES on functional capacity and muscle strength in patients before and after cardiac surgery.

METHODS

We performed a search on Pubmed, Physiotherapy Evidence Database (PEDro), Embase and CINAHL databases, selecting papers published between December 2012 and April 2023 and identified published randomized controlled trials (RCTs) that included implementation of NMES in patients before after cardiac surgery. RCTs were assessed for methodological rigor and risk of bias via the PEDro. The primary outcomes were safety and functional capacity and the secondary outcomes were muscle strength and function.

RESULTS

Ten studies were included in our systematic review, resulting in 703 participants. Almost half of them performed NMES and the other half were included in the control group, treated with usual care. Nine studies investigated patients after cardiac surgery and 1 study before cardiac surgery. Functional capacity was assessed in 8 studies via 6MWT or other indices, and improved only in 1 study before and in 1 after cardiac surgery. Nine studies explored the effects of NMES on muscle strength and function and, most of them, found increase of muscle strength and improvement in muscle function after NMES. NMES was safe in all studies without any significant complication.

CONCLUSION

NMES is safe, feasible and has beneficial effects on muscle strength and function in patients after cardiac surgery, but has no significant effect on functional capacity.

The effects of neuromuscular electrical stimulation on hospitalised adults: systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

Neuromuscular electrical stimulation (NMES) is a treatment to prevent or reverse acquired disability in hospitalised adults. We conducted a systematic review and meta-analysis of its effectiveness.

METHOD

We searched MEDLINE, EMBASE, Cumulative Index to Nursing & Allied Health (CINAHL) and the Cochrane library. Inclusion criteria: randomised controlled trials of hospitalised adult patients comparing NMES to control or usual care. The primary outcome was muscle strength. Secondary outcomes were muscle size, function, hospital length of stay, molecular and cellular biomarkers, and adverse effects. We assessed risk of bias using the Cochrane risk-of-bias tool. We used Review Manager (RevMan) software for data extraction, critical appraisal and synthesis. We assessed certainty using the Grading of Recommendations Assessment, Development and Evaluation tool.

RESULTS

A total of 42 papers were included involving 1,452 participants. Most studies had unclear or high risk of bias. NMES had a small effect on muscle strength (moderate certainty) (standardised mean difference (SMD) = 0.33; P < 0.00001), a moderate effect on muscle size (moderate certainty) (SMD = 0.66; P < 0.005), a small effect on walking performance (moderate certainty) (SMD = 0.48; P < 0.0001) and a small effect on functional mobility (low certainty) (SMD = 0.31; P < 0.05). There was a small and non-significant effect on health-related quality of life (very low certainty) (SMD = 0.35; P > 0.05). In total, 9% of participants reported undesirable experiences. The effects of NMES on length of hospital stay, and molecular and cellular biomarkers were unclear.

CONCLUSIONS

NMES is a promising intervention component that might help to reduce or prevent hospital-acquired disability.

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.

Cardiac Rehabilitation in Severe Heart Failure Patients with Impella 5.0 Support via the Subclavian Artery Approach Prior to Left Ventricular Assist Device Implantation

Impella 5.0 circulatory support via subclavian artery (SA) access may be a safe approach for patients undergoing cardiac rehabilitation (CR). In this case series, we retrospectively analyzed the demographic characteristics, physical function, and CR data of six patients who underwent Impella 5.0 implantation via the SA prior to left ventricular assist device (LVAD) implantation between October 2013 and June 2021. The median age was 48 years, and one patient was female. Grip strength was maintained or increased in all patients before LVAD implantation (pre-LVAD) compared to after Impella 5.0 implantation. The pre-LVAD knee extension isometric strength (KEIS) was less than 0.46 kgf/kg in two patients and more than 0.46 kgf/kg in three patients (unavailable KEIS data, n = 1). With Impella 5.0 implantation, two patients could ambulate, one could stand, two could sit on the edge of the bed, and one remained in bed. One patient lost consciousness during CR due to decreased Impella flow. There were no other serious adverse events. Impella 5.0 implantation via the SA allows mobilization, including ambulation, prior to LVAD implantation, and CR can be performed relatively safely.

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.

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.

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.