How do they work?

In lymphoedema, tissue water is maintained within the subcutaneous tissue and skin. Often a change in pressure will allow for the fluid to be removed, either through the lymphatic system or the veins. By applying external compression to the limb, the pressure within the tissues, and in the veins and blood capillaries, can be altered. This will facilitate the ability for the veins to absorb more fluid from the tissues. This is what happens when receiving compression therapy from bandages or garments. Most of the research surrounding IPC shows that the fluid will return to the blood circulatory system and little into the lymphatic system, meaning that pumps work better where there is a pitting or soft swelling. More modern machines intend that fluid is also returned via the lymphatic system and there is good evidence of this.

There are several additions to the pump which can influence the effectiveness by which it works. The sleeve can have several chambers which can inflate in different sequences. Chambers range from 1, 3, 6, 8 and 12. Some machines have smaller and narrower chambers than others. It is considered that the more chambers, the better the effect. Some of the chambers overlap having a more peristaltic effect. If purchasing your own machine it is recommended to not use a 1 chamber sleeve.

Sequences on the machines work differently. Many of the traditional machines will start with an inflation at the foot with the highest pressure, and this will be held but gradually reduce in pressure with each inflation of each chamber. Other sequences have a peristaltic effect commencing at the bottom of the limb and continuing to the top. Over the past 7 years, many of the new style pump sequences have been developed and altered to commence closest to the body and work down to the bottom, with the aim of decongesting the limb and clearing an area for the fluid to drain into.

Cycles on pumps are becoming more complex and follow the theory of Manual Lymphatic Drainage (MLD) closer. Some of the pumps have shown through lymphatic imaging that these sequences can remove fluid better and improve lymphatic drainage. If you have ever had any genital swelling it is important that you use one of the modern day pumps with sequences commencing proximal and working distal (closest to the body).

Are there any side effects?

Many of the pumps have adjustable pressure dials on them and on some machines these can be increased to as high as 160mmHg. This is extremely high pressure and it is suggested that you should only use pressures as high as 40mmHg. There are some reports that the initial lymphatics could be damaged by using high pressure. It is also important to remember that the pump does not know if you have a bandage or stocking on your arm/leg, so if you apply the pump in this method you may cause complications and have very high pressure to your limb. Always remove your garment before using a pump. Pumps used at high pressure could cause problems if you have any circulatory or arterial problems. In this instance they can be used but should always be used with medical supervision.

Some of the traditional pumps have been blamed for the increase of a genital oedema or for pushing fluid up to the top of the limb. This can be the case if used at high pressure and is why it is essential that you carry out Simple Lymphatic Drainage (SLD) prior to using a pump. The study identifying genital oedema looked at information historically, and concluded that genital oedema was present in 43% of pump users, regardless of the pump used, the amount of pressure, time or type of oedema.

I have carried out a study auditing the same parameters using a modern day ‘MLD pump’ and did not identify any genital oedema from the machine used. This has been presented at several international conferences. When IPC has been used within the lymphoedema services I have worked with, we had set controls and low pressure and there was no evidence of genital oedema caused on the cycle used.

Some people will want to purchase their own machine. This is fine, if you can afford it, but it is important to remember to use it under your therapist’s guidelines. This is usually for an hour a day with pressure no more than 40mmHg. This will prevent any complications. I have known some patients who have been able to manage their lymphoedema without garments by using a machine daily or twice daily, ‘sensibly’ but they are in a minority.

A course of treatment from your lymphoedema clinic will usually be daily or 3 times per week for 3 weeks. Many clinics now provide a ‘treat and go’ service where you can attend, receive supervised self-management of pump therapy and then leave. Some lymphoedema services also provide loan machines. In this instance, you will be provided with a machine to use at home. You will receive information from the therapist regarding the settings you should use. Remember that this is prescribed treatment and you must not alter the settings and use as instructed. A loan service is usually provided to patients who have stubborn lymphoedema or who have completed complex treatment and still require ‘MLD’, but maybe have to return to work and cannot take any more time off.

There are hundreds of clinics now using ‘modern’ pumps with retrograde sequences. They assist the therapists by changing the tissue softness and allowing for a faster reduction of oedema when using your hands with MLD. They will never replace Manual Lymphatic Drainage but the therapist can allow the machine to do the ‘heavy’ work and then use their hands on specific problem areas. In addition, pumps cannot easily apply compression to the body, although there are some garments for this.

Conclusion

In summary, pumps are not a new treatment but were dismissed due to the complications they caused many years ago when lymphoedema services were not yet established. Now, technology has allowed for them to work better than previously and this continues to be developed. They are getting closer to mimicking MLD but still are not able to fill the lymphatics, just disperse the fluid to somewhere it can drain better and particularly in the veins.

Ensure that you don’t get addicted to your pump if you purchase your own, there is little evidence to show that it is more effective than wearing your garment and walking! Personally, I love the pumps I have been involved with. They offer the therapist (and patients alike) a tool for altering firm and thickened tissue and reducing limb volume, but please ensure that you are supported by a good lymphoedema therapist. I can’t wait for the next new generation as technology is assisting us.

Next article: Imaging and screening for lymphoedema

Useful Articles