The importance of compression therapy in treating tissue swelling associated with lymphedema and venous insufficiency is well recognized by wound management practitioners. Compression therapy is delivered by a variety of methods with differing levels of evidence to support the use of specific compression modalities. Treatment algorithms prepared by experts from a variety of disciplines using original research are available that provide evidence ratings for particular compression modalities.1,2
In The Venous Ulcer Guideline developed by the Government and Regulatory Task Force of the Association for the Advancement of Wound Care, an “A” level of evidence was assigned to eight different compression therapy options.2 One of the eight therapeutic modalities receiving an “A” level rating was intermittent pneumatic compression.
Pneumatic compression pumps have been in use since the 1960s for the treatment of limb swelling due to both acute and chronic conditions. Pneumatic compression pumps consist of an electric pneumatic pump that is used to push compressed room air into an inflatable garment or sleeve either continuously or intermittently depending on inflation and deflation times. Most pneumatic compression pumps today use intermittent compression cycles with inflation and deflation cycles either preset or programmable by the clinician. The sleeve or garment may have a single chamber design with one port or a multiple chamber design with one port per chamber. Pressure may be graded with the highest pressures in distal chamber segments. Depending on the specific manufacturer, compression cycles, treatment times, and compression levels may be either preset or programmable. Multichamber sequential compression pumps typically provide the greatest programming flexibility. Newer compression pump technology such as the Lympha-pants™ (LymphaCare, New York, NY) employs large multi-segment chambers that cover bilateral limbs and the lower or upper trunk simultaneously so that a comprehensive treatment may be delivered in a more efficient manner. The sequential inflation of chambers from distal to proximal in these devices is also thought to more naturally mimic lymph return.
Pneumatic Compression Pump Types
Pneumatic compression pump devices are classified as one of three types3. These three basic types are:
1. Type I—nonsegmented or single compartment pumps with a single outflow port
2. Type II—segmented or multi-chamber devices with multiple outflow ports and sequential filling of the chambers at a fixed pressure
3. Type III—segmented or multi-chamber devices with multiple outflow ports and sequential filling of the chambers with manual control of pressure parameters.
It is important to note that Type II compression pumps are set up to deliver either the same pressure in each chamber segment or a preselected pressure gradient in each chamber segment. However, specific chamber pressures cannot be programmed by the clinician. In comparison, type III compression pumps may be programmed by the clinician to deliver specific levels of compression over particular inflation and deflation cycles. Some type III pumps allow the clinician to program specific levels of compression across each chamber segment.
Medicare, Medicaid, and most private insurers cover intermittent segmental, gradient pneumatic compression therapy for both lymphedema and chronic venous insufficiency (CVI) with venous stasis ulcers.4,5
In recent years, the coverage denials for pneumatic compression pumps has declined.6 Interestingly, there is a greater denial rate for CVI as compared to primary and secondary lymphedema. Pneumatic compression therapy is covered; if prescribed by a physician, if the physician provides appropriate oversight, and if certain criteria are met. Medical necessity must be well documented by the attending physician, for patients who have failed conservative treatment for lymphedema or CVI with venous statis ulcers. However, pneumatic compression therapy will not be covered as initial therapy for lymphedema or CVI.
Individuals with lymphedema must meet certain coverage criteria in order to qualify for a type I or II pneumatic compression pump.4,5 They must have a confirmed diagnosis of primary or secondary lymphedema and they must have undergone a 4-week trial of conservative therapy where symptoms did not improve or worsened. Conservative therapy includes elevation of the affected limb, exercise, massage, or use of an appropriate compression bandage system or compression garment. They must also have demonstrated compliance with the treatment plan of care.
Likewise, patients with venous insufficiency and associated stasis ulcers must have had those wounds for 6 months and have undergone and failed a 6-month trial of conservative treatment.4,5 Conservative treatment must have included a compression bandage or garment and moist wound healing treatments. Medicare also requires documentation showing ulcers have not completely healed.
Type I or II pneumatic compression therapy pumps are typically covered by Medicare.4,5 Type III pumps are considered medically unnecessary and are not covered unless the patient has certain medical conditions that warrant their use. Some Medicare reviewers currently indicate that there is a lack of research to support the use of type III devices.
Evidence for the Use of Pneumatic Compression Pump Therapy
Pneumatic compression pump therapy has been used historically to treat both lymphedema and CVI. However, the treatment of lymphedema with this therapy has become increasingly controversial in the past decade or so as more and more clinicians become certified lymphatic therapists. Pneumatic compression pump therapy has fallen out of favor with the advent of increased training and exposure of clinicians in the US to both European and Australian lymphedema management protocols. It is thought that pneumatic compression pump therapy has the potential to damage the fragile lymphatic vessels in the dermis and that this form of compression removes the fluid component of lymphedema from the swollen interstitial spaces while leaving behind the proteins that have accumulated in these spaces.7
For practitioners who use compression pumps, it is recommended that short treatment times of 30 minutes to 1 hour, one to two times per day utilizing low-moderate pressures of approximately 30 mm Hg to 35 mm Hg, followed by compression bandaging. Intermittent, sequential compression pumps with manual controls and multiple chambers (10 to 12 in number such as that provided by the Lympha-Press™ device, (Mego Afek, Kibbutz Afek, Israel) are typically recommended. Sequential filling of multiple compression chambers is thought to more efficiently move lymph proximally toward the heart.
Recommended treatment parameters are listed in Table II.
A recent review of the literature by Moseley et al,8 indicated that evidence exists to support the use of sequential pneumatic compression pump therapy in the treatment of limb swelling due to lymphedema. Five studies9–13 were systematically reviewed in this work. Of these two studies,9,12 indicated that limb volume could be reduced with pump therapy alone while the other three studies10–13 demonstrated better limb volume reduction when pneumatic compression therapy was combined with other treatment modalities. In one small study, individuals treated with an intensive regimen of sequential compression pump therapy exhibited a more rapid reduction of limb volume as compared to individuals who received manual lymphatic drainage and compression pump therapy.8 The compression pump used in this study was a sophisticated, intermittent sequential, multichambered device designed specifically for lymphedema management. Lymphedema therapists report excellent benefits with this device. However, it is costly compared to compression pumps and has fewer chambers and is not typically covered by insurance.
In another study, compression pump therapy plus a complex regimen of manual lymphatic drainage, compression bandaging, skin care, and exercise also produced a greater reduction of limb volume when compared to individuals receiving complex therapies alone.9 A study by Zelikovski et al,12 also found positive benefits associated with pneumatic compression pump therapy. This study demonstrated that compression pump therapy alone was effective in reducing arm lymphedema. It should be noted that this study employed high treatment pressures (>100 mm Hg) which are thought to produce scarring and damage of the fragile superficial lymphatics. Interestingly, a separate research group also found long-term benefits associated with high pressure sequential pump therapy.14 High pressure sequential pump therapy in combination with compression stockings was associated with long-term maintenance of reduced limb girth in 90% of patients. In comparison to the above studies, Dini et al,15 found no difference in limb volumes of patients with post-mastectomy lymphedema who either received pneumatic compression therapy or no treatment.
Taken together, the above studies indicate that pneumatic compression therapy is effective in decreasing lymphedema. Some evidence also suggests that multi-compartment devices (10 chambers) are more effective in treating lymphedema than single or three compartment pneumatic compression devices.16
Pump type and treatment parameters used in several of these studies are provided in Table III. These parameters show some similarity to those provided by the author in Table II.
A number of studies also have examined the effects of pneumatic compression therapy on wound healing and limb volume reduction in individuals with CVI. The results of these studies have been mixed. Berliner et al,17 reviewed eight studies, three of which showed that compression pumps could alleviate symptoms of CVI and assist with the healing of long-standing chronic ulcerations. However, results from a study by Rowland18 demonstrated that time to volume reduction and rates of healing were similar when intermittent pneumatic compression pump therapy was compared to compression bandaging. High pressure, intermittent pneumatic compression therapy also is being adopted for the treatment of ischemic limb tissue due to peripheral arterial disease. Several pneumatic compression technologies exist that appear to enhance vascular inflow into ischemic tissues. These devices work by enhancing the capacity for arterial inflow through the promotion of venous clearance/return. It is thought that the increased arteriovenous pressure gradient created after the leg veins empty and the decreased vascular resistance following compression, assist the cardiac system with perfusion of ischemic limb tissue. One of these therapies involves an end-diastolic pneumatic compression device. It compresses the legs after the heart beat and releases compression during systole to enhance filling of the leg arteries.19,20 Examples of pneumatic compression assist devices include the Circulator Boot™ (Circulator Boot Corp., Malvern, Pa) and the Art-Assist Device™ (ACI Medical, San Marcos, Calif). Evidence21 that this therapy is beneficial and some providers are reporting success with obtaining Medicare and Medicaid coverage of the device for their patients is increasing.
Adverse Events with Pneumatic Compression Therapy
Expert opinion indicates that high levels of compression may damage the fragile lymphatics in the dermis.7 Boris et al, also reported that treatment of CVI with pneumatic compression pumps increases the risk of genital edema.22 However, it should be noted that the pressures utilized in this study where double those recommended for individuals with lymphedema so the risk for genital edema may be less when using a lympehdema protocol for compression pump application. others have also recommended against the use of compression pumps in the presence of infection, metastatic disease and ongoing radiation.23
Pneumatic compression therapy is being used to treat chronic vascular problems including lymphedema, venous insufficiency, and arterial insufficiency. Evidence supporting the use of pneumatic compression is evolving for all three disorders. A national coverage decision exists for the use of pneumatic compression therapy for lymphedema and chronic venous insufficiency after conservative therapy has failed. Clinicians also are reporting success in regards to obtaining coverage for high-pressure pneumatic compression therapy for peripheral arterial disease. Treatment approaches and parameters once based solely on expert opinion are being supported by research studies. There appears to be a role for the judicious use of pneumatic compression given the present state of evidence.