Katherine J. Williams

Haemodynamic changes with the use of neuromuscular electrical stimulation compared to intermittent pneumatic compression

Introduction Enhancement of peripheral circulation has been shown to be of benefit in many vascular disorders, and the clinical effectiveness of intermittent pneumatic compression is well established in peripheral vascular disease. This study compares the haemodynamic efficacy of a novel neuromuscular electrical stimulation device with intermittent pneumatic compression in healthy subjects. Methods Ten healthy volunteers (mean age 27.1 ± 3.8 years, body mass index 24.8 ± 3.6 kg/m2) were randomised into two groups, in an interventional crossover trial. Devices used were the SCD Express™ Compression System, (Covidien, Ireland) and the geko™, (Firstkind Ltd, UK). Devices were applied bilaterally, and haemodynamic measurements taken from the left leg. Changes to haemodynamic parameters (superficial femory artery and femoral vein) and laser Doppler measurements from the hand and foot were compared. Results Intermittent pneumatic compression caused 51% (p = 0.002), 5% (ns) and 3% (ns) median increases in venous peak velocity, time-averaged maximum velocity and volume flow, respectively; neuromuscular electrical stimulator stimulation caused a 103%, 101% and 101% median increases in the same parameters (all p = 0.002). The benefit was lost upon deactivation. Intermittent pneumatic compression did not improve arterial haemodynamics. Neuromuscular electrical stimulator caused 11%, 84% and 75% increase in arterial parameters (p < 0.01). Laser Doppler readings taken from the leg were increased by neuromuscular electrical stimulator (p < 0.001), dropping after deactivation. For intermittent pneumatic compression, the readings decreased during use but increased after cessation. Hand flux signal dropped during activation of both devices, rising after cessation. Discussion The neuromuscular electrical stimulator device used in this study enhances venous flow and peak velocity in the legs of healthy subjects and is equal or superior to intermittent pneumatic compression. This warrants further clinical and economic evaluation for deep venous thrombosis prophylaxis and exploration of the haemodynamic effect in venous pathology. It also enhances arterial time-averaged maximum velocity and flow rate, which may prove to be of clinical use in the management of peripheral arterial disease. The effect on the microcirculation as evidenced by laser Doppler fluximetry may reflect a clinically beneficial target in microvascular disease, such as in the diabetic foot.

Neuromuscular electrical stimulation for the prevention of venous thromboembolism

Objective Venous thromboembolism, encompassing deep vein thrombosis and pulmonary embolism, is a significant cause of morbidity and mortality, affecting one in 1000 adults per year. Neuromuscular electrical stimulation is the transcutaneous application of electrical impulses to elicit muscle contraction, preventing venous stasis. This review aims to investigate the evidence underlying the use of neuromuscular electrical stimulation in thromboprophylaxis. Methods The Medline and Embase databases were systematically searched, adhering to PRISMA guidelines, for articles relating to electrical stimulation and thromboprophylaxis. Articles were screened according to a priori inclusion and exclusion criteria. Results The search strategy identified 10 randomised controlled trials, which were used in three separate meta-analyses: five trials compared neuromuscular electrical stimulation to control, favouring neuromuscular electrical stimulation (odds ratio of deep vein thrombosis 0.29, 95% confidence interval 0.13–0.65; P = .003); three trials compared neuromuscular electrical stimulation to heparin, favouring heparin (odds ratio of deep vein thrombosis 2.00, 95% confidence interval 1.13–3.52; P = .02); three trials compared neuromuscular electrical stimulation as an adjunct to heparin versus heparin only, demonstrating no significant difference (odds ratio of deep vein thrombosis 0.33, 95% confidence interval 0.10–1.14; P = .08). Conclusion Neuromuscular electrical stimulation significantly reduces the risk of deep vein thrombosis compared to no prophylaxis. It is inferior to heparin in preventing deep vein thrombosis and there is no evidence for its use as an adjunct to heparin.

The effect of footplate neuromuscular electrical stimulation on venous and arterial haemodynamics.

Objective This pilot study aims to determine the effect of the Revitive™ footplate neuromuscular electrical stimulation device on venous and arterial haemodynamic changes in healthy individuals. Method The blood flow (cc/min) and time averaged mean velocity (cm/s) of the superficial femoral vein and artery were measured using ultrasound at baseline, 15 min during, and immediately after cessation of the 30 min stimulation cycle. Data were analysed using the Wilcoxon matched-pairs signed rank test. Results Venous and arterial duplex ultrasound haemodynamic measurements were taken in 10 and 20 healthy volunteers, respectively. Mean age 38.7 (range 21–64), ankle brachial pressure index 0.9–1.0. At 15 min, there was a significant increase in venous median blood flow (88.3 cc/min, p = 0.014) and an increase in time averaged mean velocity (1.13 cm/s, p = 0.065) compared to baseline. Similarly, there was a significant increase in arterial median blood flow (38.7 cc/min, p < 0.0001) and time averaged mean velocity (2.21 cm/s, p = 0.0003) at 15 min compared to baseline. There was no significant difference in venous or arterial measurements compared to baseline after stimulation cessation. Conclusions Blood flow and time averaged mean velocity increased during neuromuscular electrical stimulation but returned to baseline once stimulation had stopped. By improving blood flow, neuromuscular electrical stimulation has the ability to enhance venous return, counteract venous stasis and improve limb arterial inflow.

A Review of the Evidence to Support Neuromuscular Electrical Stimulation in the Prevention and Management of Venous Disease

INTRODUCTION The prevention and management of venous disease is a therapeutic challenge. Movement of blood through the venous system is augmented by the action of muscles on the deep veins, and can be achieved through the application of electrical current. The efficacy of currently available clinical devices for this purpose is unknown, and is investigated here. METHODS A literature search of the EMBASE and Medline databases was performed, and studies were included if they were full text articles, written in english, pertaining to venous disease and neuromuscular electrical stimulation (NMES). RESULTS NMES devices increase venous haemodynamic parameters such as peak velocity and volume flow. Studies report them to be non-inferior to intermittent pneumatic compression. They are effective in the prevention of venous thromboembolism, though inferior to low molecular weight heparin. NMES can reduce symptoms of chronic venous disease. DISCUSSION NMES is an important tool in the prevention and management of venous disease, and avoids the significant risks associated with heparin administration. Data explored here is heterogenous in device, protocol, and reported end-points, therefore should be interpreted with care. Long term effects of treatment with NMES have not been explored.

Compression Stockings versus Neuromuscular Electrical Stimulation Devices in the Management of Occupational Leg Swelling.

Background Occupational edema is reported to occur in healthy individuals after working in a sitting or standing position for extensive periods of time. It can be associated with feelings of tiredness, heaviness of the legs, and pain. Three licensed medical devices were compared in their management of occupational edema. Subjects and Methods A total of 10 subjects were recruited from a clinical workspace. Right leg volume and great saphenous vein diameter was measured in the morning, and 6 hours later. On subsequent separate days, grade 2 graduated compression stockings (Active Compression Socks, Mediven, United Kingdom), geko (Firstkind Ltd, United Kingdom), and Revitive (Actegy Ltd, United Kingdom) were used bilaterally according to manufacturers instructions. Results Leg volumes increased by median 41 mL (p < 0.05) with no intervention. Percentage increase in leg volume was found to be significantly reduced by stockings compared with control (-1.7%, p < 0.01), and were more effective than electrical devices. Changes in vein diameter poorly correlate with leg volume changes. Conclusion Occupational edema can occur over as little as 6 hours. All devices were well tolerated and reduced leg swelling. Stockings were the only device to significantly reduce leg swelling in this small trial.

Massive localised lymphoedema: a rare vascular malformation

Lymphatic malformations are a subset of congenital vascular malformations, and are caused by a defect in lymphatic development during embryogenesis. When lymphatic mesoderm development is prematurely arrested, it retains it proliferative potential. Stimulus in the future can cause the lesion to proliferate locally without coordination or regulation, resulting in the rare condition known as massive localised lymphoedema (MLL). We present a case report of MLL, a rare and ill-defined soft tissue mass reported in the morbidly obese, with reference to the existing literature.

The comparative hemodynamic efficacy of lower limb muscles using transcutaneous electrical stimulation

BACKGROUND Circulation in the limbs can be augmented using transcutaneous electrical stimulation devices. The optimum muscle stimulation sites for enhancement of vascular hemodynamic parameters have not been identified. METHODS Seven suitable anatomic sites were identified within the right leg. Twelve healthy participants were recruited (mean age, 23.1 ± 3 years; body mass index, 23.1 ± 3 kg/m(2)). Muscles were stimulated by transcutaneous bipolar electrodes at a current twice their motor threshold, at 1 Hz, for 5 minutes. Hemodynamic ultrasound measurements were taken from the right femoral vein. Laser Doppler measurements from the feet of the stimulated and nonstimulated sides were obtained. Baseline measurements were compared with readings after 5 minutes of stimulation, with device active. Discomfort experienced for stimulation of each muscle was rated out of 100. RESULTS Hemodynamic changes displayed large intersubject variation, with no muscle statistically superior to the others. All muscles increased peak velocity; contraction of medial gastrocnemius increased time-averaged maximum velocity and volume flow. All muscles increased foot fluximetry (P < .05). Discomfort correlated weakly with current applied. Tibialis anterior and vastus lateralis were most tenable. CONCLUSIONS Transcutaneous stimulation increases hemodynamic parameters significantly, locally and systemically. No optimum stimulation site has been identified, and it is limited by comfort and variability in the subjects response. Gastrocnemius, tibialis anterior, and vastus lateralis all provoke large changes in hemodynamic parameters, but clinical efficacy in disease prevention and management has not been explored.

Chronic Intermittent Abdominal Bloating and Change in Bowel Habit: An Eight Year Diagnostic Problem Associated with Intra-Abdominal Adhesions.

Abdominal bloating is a common clinical presentation and can impact significantly on the quality of life. It can be functional or signify more serious pathology. We present a case presentation of a 38-year-old man who presented with recurrent episodes of abdominal bloating and severe debilitation for many years. He had suffered weight loss and was unable to tolerate solids. Ten years ago, he underwent an emergency laparotomy for sigmoid volvulus. In the presence of anaemia, normal imaging, and normal endoscopy, a laparoscopy was performed. At surgery, several adhesional bands were identified and resected. He had an uncomplicated recovery. Acute and chronic adhesional bowel obstruction are common presentations and carry a significant morbidity and mortality. Elective laparoscopy can be a valuable tool for diagnostic and treatment purposes. Pathology should be suspected in cases where weight loss is a feature.