All you need to know about Sequential Compression Devices

There is much misinformation circulated regarding the use of pneumatic compression devices (PCDs) in the treatment of lymphedema. I have long maintained that if you are being told that one "pump" is better than another, then you should run as fast as you can to seek better information. Lymphedema is a complex medical condition that is unique to the patient with regards to its cause, stage, availability of various treatments, patient living style, co-morbidities, etc.

No one PCD can be best for all lymphedema patients. It is the treating physician's and treating therapist's medical responsibility to determine the appropriate PCD characteristics and protocols for his or her patient at a given time, and to review periodically to determine when change may be required. As an extreme example, I would not expect that the same PCD would be appropriate for the breast cancer survivor with pure lymphedema of the upper limb as for the stage 3 lower limb patient with non-functional lymphatics.

In this time of evidence based medical decisions one looks to randomized clinical trials for support of medical decisions, but even here, one must be very careful that the trial cohort has been characterized as to their basic medical condition, and whether the results can be generalized to other populations. This was elegantly pointed out by Drs. Steven Hotta and Thomas Holohan in their 1993 Health Technology Review No. 4, AHCPR Pub. No. 93-0051 "Lymphedema Pumps: Pneumatic Compression Devices":

Since the patients selected varied from study to study and the characteristics of the lymphedema among the patients were not defined, neither the criteria for the selection of patients to be treated with one or another device nor the difference in effectiveness of the devices could be ascertained.

The following paper is, in my opinion, a well-researched discussion of the types of PCDs used in the treatment of lymphedema. I do not know who authored this paper, or whether it was published in any journal, and I would be happy to credit that person if he or she would contact me.

Pneumatic Compression Devices:
Programmable Calibrated Pressure vs. Traditional Non-Calibrated Pressure,
Appropriate Use in Treatment of Lymphedema Patients

Lymphedema is a chronic condition in which excessive fluid and proteins accumulate in the interstitial space.[1]  It can be a primary condition arising from congenital malformation of the lymphatic system, or can occur secondary to damage to lymphatic vessels or nodes. Lymphedema may present as swelling of one or more limbs and may also affect other areas including the breast, trunk and genitalia.[2]  The limited amount of controlled lymphedema research is a well-recognized problem, and absent that evidence it is necessary for clinicians to manage the condition based on the physiologic functioning of the lymphatic system.[3]  For example, professionally delivered complete decongestive therapy (CDT), while not well-researched, is supported by a wealth of clinical opinion as the optimal approach to lymphedema treatment.[4]  However, in most cases ongoing institutional based professional therapy is not a feasible long-term option. When patients are discharged from CDT, they must rely on a home program which includes bandaging, compression garments and self-manual lymphatic drainage to manage their lymphedema. In many cases, though, these conservative therapies are simply not sufficient to control this progressive condition and they end up cycling through repeated sessions of CDT. These patients would benefit from a daily home care treatment that can control their condition at an optimal level.

Pneumatic compression devices may offer a viable home care option, however medical literature does not set forth any solid guidance with regard to appropriate use of the various types of pneumatic devices when treating the lymphedema patient. Sources agree that, while there appears to be a role for pump use in lymphedema treatment, no comparative studies on pneumatic compression devices have been published that establish the most effective type of pump (single chamber vs multichamber, calibrated pressure vs non-calibrated pressure, programmable vs. non-programmable), optimal pressure levels, or appropriate treatment times.[5],[6]  This dearth of pump-specific evidence combined with lack of updated consensus on lymphedema practice standards leaves third-party payers with little upon which to base payment decisions, and as a result many payer coverage policies are based on decade-old research and outdated practice standards.

However, this absence of specific evidence on pump types, which is analogous to the lack of research supporting most lymphedema treatment, should not prevent evaluation of this intervention in terms of risks as well as in terms of benefits. "All interventions carry a balance of potential benefit and potential risk...."[7]  Also, lack of high level evidence does not preclude measurement of this intervention against what is currently known about the anatomy and physiology of the lymphatic system. In fact, in light of established knowledge of the lymphatic system, it may be difficult to conduct the desired high level research comparing pump types simply because researchers refuse to subject patients to treatments that are outdated and possibly harmful. Thus, it becomes incumbent upon lymphedema clinicians to cultivate understanding of the underlying physiology to establish treatment standards for appropriate use of the various types of pneumatic compression devices.

One of the initial barriers encountered in pursuing clarification of appropriate pump usage in current practice is the fact that lymphedema clinicians and professional societies are not fully aware of the nuances of varying levels of pump technology, and that third-party payers make coverage and payment distinctions between pump types based on technology. For instance, the NLN's 2006 position statement on lymphedema treatment broadly defines pump use as "pressotherapy" and indicates that it may be used as an adjunct to CDT, but provides no discussion of the relative merits of the various pump technologies. This same lack of pump specificity is seen throughout literature discussions which make fairly broad statements about compression pump use, but fail to distinguish pump types or how therapy is delivered by various devices.

While literature around pump use in lymphedema is rather ambiguous, it must be noted that use of traditional, non-calibrated pressure pumps has fallen from favor in lymphedema training schools and in practice in the past few years due to associated risks and limitations. When evaluating the appropriate pump for a lymphedema patient, treating clinicians tend to distinguish between pneumatic compression devices in terms of what a specific pump type can safely and effectively treat rather than in HCPCS coding terms defined by payers. For instance, a pump chosen for a patient with swelling confined to the ankle and foot may differ from the pump chosen to treat lymphedema resulting in significant pain, open wounds, or extending into the trunk or chest lymphatics. Conversely, payers may rely on codes associated with technical descriptions of pumps including whether or not they are non-segmented, segmented, or provide calibrated gradient pressure. When asked about pump use, clinicians are often unaware of the coding descriptions and technical descriptions, but tend to be quite aware of risks associated with home use of the older-generation "squeeze and hold" pumps.[8] 

Despite clinicians' lack of awareness or endorsement, a number of third-party payer coverage policies, including Medicare, rely on the position that a single chamber or a non-programmable pneumatic compression pump is sufficient to meet the needs of lymphedema patients. The basis for this position is somewhat understandable since published pump studies either used traditional 'simple' pumps (generally a non-programmable, non-calibrated pressure model) or remained silent on the type of pump used and, as discussed above, a review of medical literature offers little compelling data on any pump. That said, while even simple pumps may squeeze fluid proximally in the limb, there is much more to consider than the transient squeeze of fluid out of a limb when treating lymphedema.

A basic physiological understanding of the lymphatic system raises concern with the belief that because no evidence exists comparing pump types, then it is appropriate to continue to indiscriminately apply nonprogrammable compression pumps to lymphedema patients. While data comparing simple pumps to programmable pumps is deficient, there is significant information in medical literature that must be considered in evaluating use of pneumatic compression in treatment of lymphedema. It is on the basis of current lymphedema training and medical literature that lymphedema practitioners often refuse to prescribe non-programmable or non-calibrated pressure pumps because the known risks and limitations associated with those pumps preclude their use in lymphedema patients. As a result of the deficiencies linked to traditional (E0650-single chamber and E0651 multi-chamber noncalibrated pressure) pumps, newer generation pneumatic compression devices have been devised. These newer pumps are assigned HCPCS code E0652 because they do meet the HCPCS code definition of providing calibrated gradient pressure; however some of these devices have used the programmability of the E0652 device to not only allow for adjustability in individual segments but also to overcome the other shortcomings inherent to traditional pumps, and to provide features known to be important in lymphedema treatment.

Nonprogrammable, non-calibrated pressure pumps -
risks and shortcomings

Use of older generation, non-calibrated pressure pumps in lymphedema treatment has fallen from favor over the last several years as improved lymphedema education and increasing numbers of trained therapists leads to better understanding of the physiological impact of traditional pump therapy. Medical literature, some of which is discussed below, discusses a number of risks and potentially negative outcomes associated with indiscriminate application of traditional, non-calibrated pressure pumps.

Damage to fragile lymphatic structures. Traditional pneumatic compression devices, including those non-calibrated pressure pumps with multiple chambers, provide sustained pressures to the limb, inflating chambers sequentially with pressure holding as each subsequent chamber inflates, then deflating all chambers at once. Measurements of pressures provided to limb models by traditional pumps indicate that the pressures actually applied can far exceed the pressures being indicated by the device's pressure settings.[9]  This is a significant finding when considering that superficial lymphatic structures may be damaged if the pressures applied in therapy are too high.[10],[11]  Pressures applied in lymphedema treatment must be mild, with some experts recommending pressures no higher than 40 mm/Hg.[12]  Effective lymphedema treatment as provided by manual lymph drainage therapy is conceptually and physiologically rooted in appropriate pressure applications, and understanding the pressure timing and pattern of pneumatic compression therapy should not be ignored. One study has demonstrated significant differences in pressures applied by two compression pump systems despite identical pressures having been set.[13] 

Pain/Tolerance. Despite reports to the contrary, lymphedema can be associated with significant pain and discomfort. "A variety of myths, e.g. that lymphedema is rare, is not painful, and cannot be treated, have hindered development of lymphedema treatment programs....Research has shown that patients with lymphedema do report pain...Sensory changes and pain may be present even though the extremity appears normal...Pain can also be related to an activity that constricts lymphatic flow, e.g., wearing clothing that restricts flow in the axilla, groin, or affected body part."[14]  When considering application of a pneumatic compression to a painful lymphedematous limb, it is counterintuitive to use a device that applies that compression in the "milking squeeze and hold" fashion of a traditional pump. Indeed, in a 1997 survey of 56 compression pump users conducted by the Greater Boston Lymphedema Support Group, "pain, soreness, feeling bruised" was listed as the number one "negative result of pumping."[15]  Again, like most publications, this one did not distinguish between pump types and associated negative outcomes, but clearly a subset of lymphedema patients struggle with pain and inability to tolerate some forms of pneumatic compression.

Development of fibrotic cuff. Because traditional pump sleeves (appliances) cover only the limb (ending at the proximal limb), protein-rich fluid is forced to the top of the limb where it pools, causing a chronic inflammatory response and eventually a fibrotic band where the pump sleeve ends, further impeding lymphatic outflow.[16],[17] 

Creation of new areas of lymphedema. One of the most serious risks associated with traditional pump use is development or exacerbation of lymphedema in the chest, trunk, abdomen or genitalia.[18],[19]  "To squeeze edema fluid toward the groin or axilla of a lymphedematous limb especially if the regional lymph nodes have been removed or are diseased, defies an understanding of basic anatomy and physiology. The adjacent quadrants of the trunk are alternate lymphatic drainage pathways for both the axilla and inguinal region as are the genitalia for the leg lymphatics. Accordingly, it is common after standard compression therapy to see iatrogenic swelling of the genitalia as peripheral edema fluid has been translocated and then trapped more proximally."[20]  Development of truncal lymphedema can lead to growth of fibrosclerotic tissue in those regions, increased pain and disability as well as exacerbating psychosocial issues, especially with genital lymphedema.

Inability to treat truncal lymphatics. Lymphedema is often not confined to just the obviously swollen limb. Because the adjacent trunk quadrant belongs to the lymphatic tributary area of the axillary or inguinal nodes, the lymphatic congestion in many cases goes far beyond what is clinically evident, extending beyond the limb into the torso.[21] . Recognition and treatment of truncal involvement is necessary to achieve positive lymphedema outcomes.[22]  Traditional (E0650/E0651) pumps have no appliances or programmability to treat truncal lymphedema; indeed as described above, they may exacerbate truncal lymphedema by forcing fluid from the limb into the compromised truncal lymphatics.

Fibrosis treatment. Lymphedema is a high-protein edema; the lymph system's role, among others, is to transport protein. When the lymph system is impaired, protein and fluid accumulation initiates a marked inflammatory reaction. The resulting fibrosis then further impedes lymphatic function, thereby creating a vicious cycle that leads to chronic and progressive lymphedema.[23] 

Treatment of fibrosis is a fundamental component of lymphedema therapy. However, traditional pumps have no ability to focus treatment on fibrotic areas, they can only re-treat the entire limb which may be counterproductive to overall outcomes.

Programmable, calibrated pressure pneumatic compression devices — overcoming the problems with traditional pump use in lymphedema treatment

The information set forth above clearly raises questions regarding indiscriminate use of nonsegmental or nonprogrammable pumps in lymphedema treatment. While the head- to-head research on pumps may not provide evidence that programmable pumps provide "superior" outcomes over nonprogrammable pumps in terms of fluid squeezed from the limb, the published literature discussed above does indicate there is significant physiological basis for having reservations in use of nonprogrammable, non-calibrated pressure pumps in many lymphedema patients.

The question remains, then, whether and when programmable (E0652) pneumatic compression devices with calibrated gradient pressure are appropriately prescribed for lymphedema treatment. What unique characteristics may be presented by the lymphedema patient that would require the features offered by an E0652 pump?

The initial basis for Medicare's development of the E0652 code was to describe a device designed to address an identified need to have the ability to adjust segmental pressures when clinically appropriate, since nonprogrammable pumps do not offer that adjustability. Is that adjustability necessary? Since for some patients pain and inability to tolerate sustained pressures is a barrier to compliance with pumps, the answer is yes, there is a need for adjustable pressures for some patients.

However, the adjustability and features that can be afforded by E0652 pumps are not limited to adjustable pressure in multiple chambers. E0652 devices have been subject to "technology creep" over the past five years as clinicians continue to identify features that are clinically necessary to provide safe, effective, comprehensive treatment for the lymphedema patient. As a result some E0652 pumps not only offer ability to adjust segmental pressures, but also to overcome the significant risks and shortcomings of non-segmented, non-calibrated pressure pumps described above, thereby offering safe treatment while applying effective therapy. Examples of features offered by some E0652 pumps include:

  1. Programmability for comfort, tolerance, and ability to focus on fibrotic tissues. Pump pressure profiles that more closely emulate the gentle stretch and release motions of manual lymphatic drainage therapy (MLD) reduce risk of damage to fragile superficial lymphatics. This program design approach, offered by some E0652 pumps, overcomes the risk of lymphatic damage by providing effective lymphedema treatment[24]  using pressure profiles that differ from traditional pumps in timing, pattern and magnitude.[25]  In the latter study, average pressures, peak pressures and the pressure-time integral were all significantly greater for the traditional pump. Pumps that offer programmability with calibrated gradient pressures allow for adjustability to address painful areas and some also provide programs that can retreat specific areas of fibrosis. Using specific E0652 pumps have proven to aid in tolerance, compliance with recommended treatment regimens and satisfaction with physical improvement in patient reported symptoms.[26] 
  2. Appliances and programs to treat truncal lymphatics. Some E0652 pumps offer features to address the risk associated with treating only the lymphedematous extremity. These pumps provide sleeves (appliances) that can be applied to the chest and trunk together with programming to move fluid through the affected limb, across the often damaged inguinal or axillary region and to treat the adjacent truncal lymphatics. This design not only reduces any risk of developing a fibrotic cuff at the proximal limb, but clearing truncal lymphatics also helps prevent development or exacerbation of truncal, chest and genital edema. If one accepts that pneumatic compression effectively treats lymphedema in the limb, then certainly there is no reason why lymphedema in other anatomical regions should not be effectively treated with pneumatic compression therapy.

While existing pump research may not conclude that programmable pumps provide "superior" outcomes over traditional nonprogrammable pumps in terms of reducing volume, the published literature clearly raises concerns with injudicious use of nonprogrammable pumps in lymphedema treatment due to the significant risks and shortcomings associated with older generation pumps. Traditional (E0651) pumps may be safe and effective for some patients with "swelling", but clearly those devices are not clinically appropriate for many lymphedema patients due to potential complications and technology limitations.

Third party payer coverage policies should not just rely on the existing head to head pump research because that data fails to paint the entire physiological picture. Instead these policies must also consider the documented risks associated with traditional pneumatic devices as well limitations inherent in nonprogrammable technology, in order to reflect the safe and appropriate use of pneumatic compression devices in lymphedema patients.