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Wednesday, October 14, 2009

Lymphedema and the Use of Diuretics

Lymphedema and the Use of Diuretics

Because of the incredible lack of awareness and/or knowledge of lymphedema in the medical community, it is very common to hear of lymphedema patients speak of being prescribed diuretics (water pils) by their physcians in attempting to treat this condition.

It is important to understand not only that diuretics are not for lymphedema, but to understand why.

The long term use of diuretics will eventually lead to a serious worsening of lymphedema and will help set the stage for increased complications such as tissue fibrosis.

Hopefully, this page will clear up questions regarding this and will help patients better manage their lymphedema.

Pat

Diuretics Definition

A class of drugs or other substance that promotes the formation and release of urine. Diuretics are used to decease the fluid volume in the treatment of many underlying medical conditions. Most people commonly call diuretics a “water pill.”

Anything that promotes the formation of urine by the kidney. (The word “diuretic” comes from a combination of the Greek “dia-”, thoroughly + “ourein”, to urinate = to urinate thoroughly).

Diuresis may be due to a huge number of causes including metabolic conditions such as diabetes mellitus (in which the increased glucose level in the blood causes water to be lost in the urine); substances in food and drink (such as coffee, tea, and alcoholic beverages); and specific diuretic drugs.

All diuretic drugs – which are usually called, more simply, diuretics – cause a person to “lose water” but they do so by diverse means, including:

Inhibiting the kidney's ability to reabsorb sodium, thus enhancing the loss of sodium in the urine. And when sodium is lost in the urine, water goes with it. (This type of diuretic is called a high-ceiling diuretic or a loop diuretic).

Enhancing the excretion of both sodium and chloride in the urine so that water is excreted with them. This is how the thiazide diuretics work. Blocking the exchange of sodium for potassium, resulting in excretion of sodium and potassium but relatively little loss of potassium. These diuretics are therefore termed potassium sparing diuretics. Some diuretics work by still other mechanisms. And some diuretics have other effects and uses such as in treating hypertension. (3)

Lymphedema or Edema?

To understand why these agents are not recommended for the treatment of lymphedema we must first start with a basic definition of edema and lymphedema.

Edema: Abnormal pooling or build up of fluid in tissues. Generally caused by underlying medical conditions such as hypertension, varicose veins, thrombophlebitis, congestive heart failure, kidney failure, steroid therapy, inflammatory reactions, or injury or trauma.

Diuretics are used to assist in the correction of the base problem causing the edema.

Lymphedema: A disorder in which “lymph” collects usually in a limb as a result of a congenital, hereditary malformation of the lymphatic system, or is a result secondary conditions such as node removal for biopsies, damage to the lymphatics from radiation, injury or trauma or by parasitic infection. Diuretics cannot help the underlying condition of lymphedema.

Why not use diuretics for lymphedema?

Perhaps the single most important consideration is in the composition of the lymph fluid caused by lymphedema. The fluid i a protein-rich substance that provides a breeding and nourishment center for bacteria. This has to be removed to lesson the risks of cellulitis and lymphangitis.

This fluid also has to be removed so as to prevent the formation and progression of fibrosis as lymphedema advances through the various stages.

Diuretics remove none of this waste fluid as it is a heavier molecule fluid then just water itself..

Diuretics and Lymphedema

A question that came up is whether diuretics should be used in the treatment of lymphedema. In my opinion, the answer is usually no. There are some exceptions and I will explain.

Diuretics are one of the best treatments for patients suffering from edema of the legs due to congestive heart failure. When the right side of the heart does not work efficiently, the pressure in the venous system increases and this, in turn, results in increased pressure in the tissues and edema results. The edema is not from the lymphatic system and is not lymphedema.

Diuretics, such as lasix, cause the kidney to eliminate water from the blood. This in turn reduces the pressure in the venous system and allows the edema to drain into the venous system. Unfortunately, when someone drinks additional water the fluid and edema returns and so many patients require fluid and salt restriction to have the best results. Diuretics must be given regularly to eliminate as much water from the blood system as possible and control the edema. In some case, even when high doses of diuretics are given, the edema cannot be controlled by drugs alone and compression garments can be of additional benefit for these patients. The lymphatic system can be completely normal and patients will still develop edema due to congestive heart failure.

The lymphatic system drains through the lymph nodes and lymphedema generally arises due to an obstruction in the lymphatic system. This can occur due to surgery, radiation or trauma. Decreasing the pressure in the venous system by removing water from the venous system does not help reduce lymphedema. In fact, patients with normal cardiac function do not have excess tissue edema. As a result, fluid removed by diuretics must be replaced by oral intake to maintain a normal fluid balance and any reduction in fluid due to diuretics in normal people is temporary. Diuretics have no value for the treatment of lymphedema in patients who do not have edema due to congestive heart failure or other similar conditions.

A patient could have a mixed condition where lymphedema is complicated by edema due to congestive heart failure. These patients may benefit from treatment with diuretics because of the mixed condition. Check with your doctor to see if you have some component of edema.

Dr. Mortimer addressed this question in a recent publication in Angiology 48:87-91, 1997. He said,

“Lymphedema, regardless of etiology, is essentially incurable but different therapy approaches exist which serve to contain swelling. The objectives of treatment are to reduce swelling, restore shape, and prevent inflammatory episodes, eg, recurrent cellulitis. There are essentially three main approaches to lymphedema treatment: physical therapy, drug therapy, and surgery. Any edema arises from an imbalance between capillary filtration and lymph drainage. The principle of physical therapy is to a) reduce excessive capillary filtration and b) improve drainage of interstitial fluid and macromolecules from congested regions to normally draining lymph node sites. This is achieved through a combination of compression, exercise, and if possible, massage. Control of recurrent inflammatory episodes can only be achieved through diabetic type skin care, a reduction in swelling, and if necessary, prophylactic antibiotics. Drug therapy comprises diuretics or the coumarin/flavonoid group of drugs. The use of diuretics for pure lymphedema is physiologically unsound but may be of use in edema of mixed origin and in palliative (cancer) circumstances.”

Tony Reid MD Ph.D

Penninsula Medical Diuretics Page

Acknowledgment

Penninsula Medical - “The Reidsleeve People”


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