External Pneumatic Compression Device Research Articles

Effects of an external pneumatic compression device vs static compression garment on peripheral circulation and markers of sports performance and recovery.

To identify the effects of a single 30min partial lower leg external pneumatic compression (EPC) treatment compared to a static compression (SC) garment or a no treatment control (CTL) on markers of recovery and performance following a muscle damaging protocol. Thirty healthy, active males(23 ± 3years; 180.2 ± 9.0cm; 81.6 ± 11.3kg) performed 100 drop jumps from a 0.6m box followed by a randomized, single 30min treatment of either a partial lower leg EPC device worn below the knee and above the ankle (110mmHg), SC garment (20-30mmHg) covering the foot and calf just below the knee, or no treatment CTL, and then returned 24 and 48h later. Participants were assessed for measures of muscle soreness, fatigue, hemodynamics, blood lactate, muscle thickness, circumferences, and performance assessments. The drop jump protocol significantly increased muscle soreness (p < 0.001), fatigue (p < 0.001), blood flow (p < 0.001), hemoglobin (p < 0.001), and muscle oxygen saturation (SMO2; p < 0.001). Countermovement jump and squat jump testing completed after treatment with either EPC, SC, or CTL revealed no differences for jump height between any condition. However, EPC treatment maintained consistent braking force and propulsive power measures across all timepoints for countermovement jump testing. EPC and SC treatment also led to better maintenance of squat jump performance for average relative propulsive force and power variables at 24 and 48h compared to CTL. A single 30min partial leg EPC treatment may lead to more consistent jump performance following a damaging bout of exercise.

Synovial Fluid Cytokines, Chemokines and MMP Levels in Osteoarthritis Patients with Knee Pain Display a Profile Similar to Many Rheumatoid Arthritis Patients.

Background: There are currently no effective disease-modifying drugs to prevent cartilage loss in osteoarthritis and synovial fluid is a potentially valuable source of biomarkers to understand the pathogenesis of different types of arthritis and identify drug responsiveness. The aim of this study was to compare the differences between SF cytokines and other proteins in patients with OA (n = 21) to those with RA (n = 27) and normal knees (n = 3). Methods: SF was obtained using ultrasound (US) guidance and an external pneumatic compression device. RA patients were categorized as active (n = 20) or controlled (n = 7) based upon SF white blood cell counts (> or <300 cells/mm3). Samples were cryopreserved and analyzed by multiplex fluorescent bead assays (Luminex). Between-group differences of 16 separate biomarker proteins were identified using ANOVA on log10-transformed concentrations with p values adjusted for multiple testing. Results: Only six biomarkers were significantly higher in SF from active RA compared to OA—TNF-α, IL-1-β IL-7, MMP-1, MMP-2, and MMP-3. Only MMP-8 levels in RA patients correlated with SF WBC counts (p < 0.0001). Among OA patients, simultaneous SF IL-4, IL-6, IL-8, and IL-15 levels were higher than serum levels, whereas MMP-8, MMP-9, and IL-18 levels were higher in serum (p < 0.05). Conclusion: These results support the growing evidence that OA patients have a pro-inflammatory/catabolic SF environment. SF biomarker analysis using multiplex testing and US guidance may distinguish OA phenotypes and identify treatment options based upon targeted inflammatory pathways similar to patients with RA.

Peripheral conduit and resistance artery function are improved following a single, 1-h bout of peristaltic pulse external pneumatic compression.

External pneumatic compression (EPC) is being employed for a widening range of clinical and non-clinical populations. However, EPC devices vary markedly in treatment pressures, duty cycles and application sites, and the acute effects of whole limb, lower pressure EPC on peripheral vascular function have not been determined. The purpose of this study was to determine the acute effects of a single bout of peristaltic pulse EPC on peripheral conduit and resistance artery function. Twenty (n = 20; males = 12 and females = 8) young and apparently healthy subjects (aged 26.1 ± 8.2 years) participated in this study. A sequential EPC device with five inflation zones arranged linearly and inflating distal to proximal along the lower limbs was employed with target inflation pressures of 70 mmHg for 1 h. Flow-mediated dilation (FMD) of the brachial and popliteal arteries was evaluated with ultrasound before and after EPC. Venous occlusion plethysmography was employed to evaluate limb blood flow at rest and during reactive hyperemia (RH) in the forearm (FBF) and calf (CBF) before and after EPC. Peak RH CBF was increased by 9 % after EPC (P < 0.05), whereas peak RH FBF (-10 %) did not change significantly (P > 0.25). Normalized popliteal artery FMD post-EPC (2.24 ± 1.41) was significantly higher than pre-EPC (1.36 ± 0.67, P = 0.015) and post-sham (1.58 ± 0.86, P = 0.032) values. Similarly, normalized brachial artery FMD post-EPC (1.47 ± 0.32) was significantly higher than pre-EPC (1.11 ± 0.41, P = 0.004) and post-sham (0.99 ± 0.27, P = 0.026) values. Acutely, whole limb, lower pressure EPC improves conduit artery endothelial function systemically, but only improves RH blood flow locally (i.e., compressed limbs).

Acute Effects of an External Pneumatic Compression Device on Local and Systemic Resistance Vessel Reactivity and Limb Blood Flow

High pressure external pneumatic compression (e.g. EECP) has been shown to have marked benefits on vascular reactivity and biology. However it is expensive, uncomfortable, and not easily accessible. Alternatively, low pressure EPC is commercially available, does not require medical supervision, and is low risk.PurposeThe purpose of this study was to determine the acute effects of low pressure EPC on resting limb blood flow and resistance vessel reactivity in compressed and non‐compressed limbs of healthy young subjects.MethodsTen (n=10) apparently healthy subjects (aged 27.0 ± 10.2 years) were enrolled in this randomized, crossover design study. Subjects reported in the morning, fasted, for two visits separated by at least 24‐hours. Prior to and immediately following application of EPC or sham for 60 minutes, forearm (FBF) and calf blood flow (CBF) were evaluated at baseline and during 3 minutes of reactive hyperemia (RH) using venous occlusion plethysmography. A peristaltic pulse dynamic compression device was employed for EPC treatment with target inflation pressures of ~70 mmHg applied to the lower limbs.ResultsEPC significantly improved peak CBF, but no differences in resting FBF, peak FBF, resting CBF, total CBF and total FBF were observed. imageConclusionsEPC significantly improves acute resistance vascular reactivity in compressed limbs, but not non‐compressed limbs, following 60 minutes of treatment. Therefore, application of low pressure EPC may be efficacious in situations where local alterations of resistance vessel reactivity is desirable.Partial support for this study was provided by the Quinnipiac University Interdisciplinary Program for Research &amp; Scholarship and by NormaTec (Newton Centre, MA)

Acute Effects of External Pneumatic Compression on Peripheral and Central Hemodynamics

Use of external pneumatic compression (EPC) to improve recovery after exercise is increasing. However, the acute hemodynamic effects of EPC have not been determined. The purpose of this study was to investigate the acute effects of EPC on the aortic pressure waveform (AoPW) during EPC therapy. Twenty (n=20) young participants (23.5±3.9 years) were included in this study. Analysis of the AoPW was evaluated continuously using applanation tonometry before, during, and after a single 1‐hr therapeutic session of EPC. A sequential EPC device was employed with target inflation pressures of ~100 mmHg of compression. Peripheral systolic blood pressure was increased by 5.8±1.3 mmHg during EPC and remained elevated 10 minutes post treatment, p&lt;0.05. Aortic systolic blood pressure was increased by 5.9±1.1 mmHg during EPC and remained elevated 10 minutes post treatment, p&lt;0.01. Both peripheral and aortic diastolic blood pressure were significantly increased by 5.1±0.9 and 4.8±0.9 mmHg, respectively, during EPC and remained elevated 10 minutes post treatment, p&lt;0.05. Peripheral and aortic mean arterial pressure were increased by 4.2±1.0 and 4.3±1.1 mmHg, respectively, during EPC and remained elevated 10 minutes post treatment when compared to baseline values, p&lt;0.05. EPC at target inflation pressures of 100mmHg increases total peripheral resistance to lower limb blood flow which results in increases in peripheral and central blood pressures during therapy and persists at least 10 minutes post treatment.

External pneumatic compression device prevents fainting in standing weight-bearing MRI: a cohort study

To investigate if a peristaltic external pneumatic compression device attached to the legs, while scanning, can reduce a substantial risk of fainting in standing weight-bearing magnetic resonance imaging (MRI). This study comprised all patients with low back pain referred to standing MRI of the lumbar spine, using a 0.25-T open G-Scanner, from June 2011 to April 2012. The standing MRI protocol included a sagittal TSE T2w and an axial GRE T2w sequence giving a total scan time of 17min. The first patients were scanned standing without a device (control group), and then from January to April 2012 the patients were scanned in the standing position using an external pneumatic compression device, attached to the legs (experimental group). One hundred and forty-nine patients (mean age 42.5, standard deviation 12.5, and range 20-77years) were included and scanned standing. No significant difference in age (p = 0.51) or gender (p = 0.47) was observed between the control group (n = 86) and the experimental group (n = 63). Sixteen patients (19%) fainted in the control group during the standing MRI scan, compared to one patient (2%) in the experimental group where the pneumatic compression device was applied. The difference between groups was highly significant (p = 0.001; Fisher's exact test), with an OR = 0.071 (exact 95%CI: 0.002 to 0.486) for the pneumatic compression device. A substantial risk of fainting during standing MRI was almost eliminated by using an external peristaltic pneumatic compression device.

State-of-the-art thrombosis prevention and treatment

Thrombosis is the leading cause of death in developed countries, with arterial thrombosis presenting as myocardial infarction, stroke or peripheral arterial occlusion. Venous thromboembolism (VTE) is a major cause of mortality worldwide, despite some variations in prevalence of the disease [1]. While the incidence of VTE increases with aging, it is the leading cause of vascular morbidity in young adults. A multitude of risk factors can contribute to presentation of VTE [2]. This includes transient risk factors such as trauma, surgery, immobilization, long-haul flights, acute medical illness, hormonal therapy and pregnancy. Long-standing risk factors include chronic conditions such as congestive heart failure, chronic lung disease, inflammatory bowel disease and nephrotic syndrome. The discovery of thrombophilic risk factors opened a new era of genetic assessment of the predisposition for VTE with potential ability for better definition of the risk associated with transient risk factors. For example, hormonal therapy in women with thrombophilic risk factors, such as Factor V Leiden and the prothrombin gene polymorphism, multiply the risk for VTE [3]. While testing for thrombophilia is appealing, wider application has been hampered by equivocal cost-effectiveness analysis. A screening test for thrombophilia would be useful, and global assays such as the Protein C Global have been suggested in this regard [4]. In general, VTE is preventable by application of prophylactic measures. Applying early mobilization and physical measures such as elastic stockings and external pneumatic compression devices is useful. The current pharmacological approach is based on unfractionated, low-molecular-weight heparins (LMWH) and fondaparinux. Vitamin K

Efficacy of mechanical prophylaxis for venous thromboembolism in patients with brain tumors

Patients with brain tumors are at considerable risk for the formation of venous thromboemboli. One method of preventing these complications is mechanical prophylaxis in which an external pneumatic compression device and graduated elastic compression stockings are used. Evidence indicates that these devices prevent deep venous thrombosis (DVT) and pulmonary embolism (PE) by limiting venous stasis and increasing fibrinolytic activity at both the local and systemic levels. The authors present evidence for the occurrence of both mechanisms and discuss the use of mechanical compression in the setting of surgery for brain tumors. They also present data proving the efficacy of these devices in patients who undergo craniotomy with motor mapping for resection of glioma and in whom the contralateral leg receives no prophylaxis. Finally, they comment on the use of anticoagulation therapy both in addition to and in place of mechanical prophylaxis.

The effect of external pneumatic compression on regional fibrinolysis in a prospective randomized trial

External pneumatic compression devices (EPC) prevent deep venous thrombosis (DVT) by reducing lower extremity venous stasis. Early studies suggested they also enhance fibrinolytic activity; however, in a recent study, EPC had no effect on systemic fibrinolysis in patients undergoing abdominal surgery. The hypothesis of this study was that EPCs enhance regional fibrinolysis in these subjects. Forty-five patients (44 male, one female; mean age, 67 years) undergoing major abdominal surgery (35 bowel procedures, 10 aortic reconstructions) were prospectively randomized to one of three groups for DVT prophylaxis: subcutaneous heparin injections (HEP), thigh-length sequential EPC devices (EPC), or both (HEP+EPC). Prophylaxis was begun immediately before surgical incision and continued until postoperative day 5 or patient discharge. Venous blood samples were collected from the common femoral vein for measurement of regional fibrinolysis after induction of anesthesia but before initiation of prophylaxis, and on postoperative days 1, 3, and 5. A baseline sample was collected the day before surgery. Fibrinolysis was quantified with measurement of the activities of tissue plasminogen activator (tPA; the activator of fibrinolysis) and its inhibitor plasminogen activator inhibitor-1 (PAI-1) with amidolytic technique. tPA activity in all groups was normal at baseline; baseline PAI-1 activity was elevated. Within each prophylaxis group, no significant changes occurred in either tPA or PAI-1 activities after induction of anesthesia or after surgery compared with before surgery (P >.05, analysis of variance with repeated measures). No changes occurred between postoperative samples and after anesthesia within each group. No significant enhancement of fibrinolysis, manifested as either increased tPA activity or decreased PAI-1 activity, occurred in either EPC group compared with the HEP group at any time point (P >.05, analysis of variance with repeated measures). No differences were noted when surgery was performed for malignant disease versus nonmalignant disease. In this study, enhanced regional fibrinolysis in the lower extremities could not be detected with the use of EPCs, as measured with tPA and PAI-1 activity in common femoral venous blood samples. EPC devices do not appear to prevent DVT with fibrinolytic enhancement; effective and safe prophylaxis is provided only when the devices are used in a manner that reduces lower extremity venous stasis.

Preference and Compliance in Postoperative Thromboembolism Prophylaxis Among Gynecologic Oncology Patients

In Brief OBJECTIVE To compare low molecular weight heparin and external pneumatic compression in terms of patient preference and compliance to determine if either of these two methods is superior in postoperative thromboembolism prophylaxis of gynecologic oncology patients. METHODS A total of 211 patients undergoing major surgery for a suspected gynecologic malignancy were randomized to receive thromboembolism prophylaxis with either external pneumatic compression or low molecular weight heparin. Surveys regarding thromboembolism prophylaxis were completed by patients before surgery and approximately 7 days postoperatively. Patient preferences as well as reasons for patient dissatisfaction with prophylactic methods were elicited in the questionnaires. In addition, patient compliance with prophylaxis was recorded twice a day during hospitalization. Patients were not considered to be compliant with prophylaxis if the external pneumatic compression device was not functioning properly or if the administration of low molecular weight heparin was not given in a timely manner. RESULTS The majority of patients were satisfied with the prophylactic method that they received to the extent that they would prefer the treatment they received to one they had not necessarily experienced. The postoperative preferences of 78% of patients receiving low molecular weight heparin and 74% of those wearing external pneumatic compression corresponded to what the patients actually received as a method of thromboembolism prevention. Patient compliance with prophylaxis was noted to be inadequate in ten of 104 (9.6%) patients receiving external pneumatic compression and seven of 103 (6.8%) patients receiving low molecular weight heparin. CONCLUSION Pneumatic compression and low molecular weight heparin are similar both in terms of patient preference and compliance among gynecologic oncology patients receiving postoperative thromboembolism prophylaxis. Pneumatic compression and low molecular weight heparin are similar both in terms of patient preference and compliance among gynecologic oncology patients receiving postoperative thromboembolism prophylaxis.

Preference and compliance in postoperative thromboembolism prophylaxis among gynecologic oncology patients

OBJECTIVE: To compare low molecular weight heparin and external pneumatic compression in terms of patient preference and compliance to determine if either of these two methods is superior in postoperative thromboembolism prophylaxis of gynecologic oncology patients. METHODS: A total of 211 patients undergoing major surgery for a suspected gynecologic malignancy were randomized to receive thromboembolism prophylaxis with either external pneumatic compression or low molecular weight heparin. Surveys regarding thromboembolism prophylaxis were completed by patients before surgery and approximately 7 days postoperatively. Patient preferences as well as reasons for patient dissatisfaction with prophylactic methods were elicited in the questionnaires. In addition, patient compliance with prophylaxis was recorded twice a day during hospitalization. Patients were not considered to be compliant with prophylaxis if the external pneumatic compression device was not functioning properly or if the administration of low molecular weight heparin was not given in a timely manner. RESULTS: The majority of patients were satisfied with the prophylactic method that they received to the extent that they would prefer the treatment they received to one they had not necessarily experienced. The postoperative preferences of 78% of patients receiving low molecular weight heparin and 74% of those wearing external pneumatic compression corresponded to what the patients actually received as a method of thromboembolism prevention. Patient compliance with prophylaxis was noted to be inadequate in ten of 104 (9.6%) patients receiving external pneumatic compression and seven of 103 (6.8%) patients receiving low molecular weight heparin. CONCLUSION: Pneumatic compression and low molecular weight heparin are similar both in terms of patient preference and compliance among gynecologic oncology patients receiving postoperative thromboembolism prophylaxis.

External pneumatic compression and fibrinolysis in abdominal surgery

Introduction: External pneumatic compression (EPC) devices prevent lower extremity deep venous thrombosis by increasing venous flow and thereby reducing stasis. Early studies suggested that they also enhance systemic fibrinolytic activity and thus prevent thrombus formation; more recent studies have been conflicting. The hypothesis of this study was that EPC devices enhance systemic fibrinolysis or reduce postoperative fibrinolytic impairment in patients undergoing abdominal surgical procedures. Methods: Each of 48 patients (98% male; mean age, 67 years) undergoing major intra-abdominal surgical procedures (36 bowel procedures, 12 aortic reconstructions) was prospectively randomized to one of three treatments for deep venous thrombosis prophylaxis: subcutaneous heparin injections (HEP group), use of a thigh-length sequential EPC device (EPC group), or both (HEP + EPC group). Antecubital venous samples were collected for measurement of systemic fibrinolytic activity on the day before surgery, after induction of anesthesia but before prophylaxis was initiated, and on postoperative days 1, 3, and 5. Fibrinolysis was assessed through measurement of the activities of the rate limiting fibrinolytic activator, tissue plasminogen activator, and its inhibitor plasminogen activator inhibitor-1 with amidolytic methods. Results: On the day before surgery, plasminogen activator inhibitor-1 activity was elevated in all groups in comparison with that in age-matched and sex-matched controls (20.3 ± 0.6 AU/mL). In the HEP group, plasminogen activator inhibitor-1 activity was further elevated above the value for the day before surgery on postoperative day 1 (28.5 ± 4.3 AU/mL; P =.04) and postoperative day 3 (25.1 ± 1.9 AU/mL; P =.07). No significant decrease in plasminogen activator inhibitor-1 activity occurred in either group treated with EPC devices in comparison with the HEP group at any time. There were no changes in tissue plasminogen activator activity postoperatively in the HEP group and no significant increases in either EPC group at any point. Conclusions: Reduced systemic fibrinolytic activity (“fibrinolytic shutdown”) occurred in these patients after abdominal surgery; it was manifested as increased plasminogen activator inhibitor-1 activity. EPC devices did not enhance systemic fibrinolysis or prevent postoperative shutdown either by decreasing plasminogen activator inhibitor-1 activity or by increasing tissue plasminogen activator activity. These data suggest that EPC devices do not prevent deep venous thrombosis by fibrinolytic enhancement; effective prophylaxis is achieved only when the devices are used in a manner that reduces lower extremity venous stasis. (J Vasc Surg 2000;32:537-43.)

Why does prophylaxis with external pneumatic compression for deep vein thrombosis fail?

External pneumatic compression (EPC) devices are increasing in popularity for deep vein thrombosis (DVT) prophylaxis. Patients who have these devices applied postoperatively are assumed to have effective prophylaxis, although a number of extensive postoperative DVT complications have been observed. This study evaluates the proper application of EPC devices in patients in intensive care units and regular nursing floor units and assesses whether dedicated in-service instruction can improve proper use. In a prospective study of 138 patients with 2 or more risk factors for postoperative DVT, it was found that patients on routine nursing units had properly functioning EPC devices during 48% (306 of 636) of the visits compared with 78% (312 of 398) of the visits in the intensive care unit (ICU) (p less than 0.0001). Follow-up of patients transferred from an ICU to a regular nursing unit showed that functional application decreased from 82% (129 of 157) to 33% (40 of 122) (p less than 0.005). The compression sleeves were not applied in 84% of the nonfunctional devices and were properly in place but the pump nonfunctional in 16%. Unfortunately, dedicated in-service instruction did not improve the proper use of EPC. Although proper application of EPC is better in the ICU compared with regular nursing units, improper use is frequent and failure of DVT prophylaxis with EPC devices may be due to improper use, rather than failure of the method itself.

Ulcerated edematous limbs: Effect of edema removal on transcutaneous oxygen measurements

We studied the effect of edema removal on transcutaneous oxygen tension (TcPO 2) in eight patients with leg ulcers. An external pneumatic compression device was effective in removing edema from the ulcerated limbs over a 5-day course of treatment, at which time all treated limbs were clinically free of edema. TcPO 2 levels at room air at the ulcer site were markedly reduced when compared with the control chest site, both before and after external pneumatic compression device therapy ( p<0.001). Edema removal, however, did not significantly alter TcPO 2 values ( p>0.9). No significant positional effects on TcPO 2 values were noted with patients supine, sitting, or with the affected limbs elevated. Five patients (63%) had increased TcPO 2 values adjacent to the ulcer site when receiving supplemental oxygen. For these patients, TcPO 2 values increased after oxygen inhalation, both before and after edema removal ( p<0.05). We conclude that TcPO 2 values are markedly reduced in ulcerated edematous limbs. Edema, however, may not constitute a barrier to oxygen diffusion through the skin and does not account for the low TcPO 2 values in the ulcerated edematous limb. Therefore the positive therapeutic effect of removing edema is unlikely to be related to better oxygenation of the tissues.