Edema is basically a physical observation when body tissues swell because of fluid build-up within the interstitial spaces. It can be an indication that something is wrong either locally or systemically, so, it is important to seek medical work-up with the clinician to determine any underlying causes of edema. Clinically, when an observable edematous part of the body is measured, a finger is pressed on the affected area which can either leave an indentation for a moment, or the skin will just spring back to its original level. Because of this description, edema is classified as pitting or non-pitting edema and pitting happens because the fluids that fill the interstitial spaces are poor in protein and lymphatic drainage is not obstructed. The amount of excess body fluid that the body will collect in the tissue before pits on edematous area appear is at least 10 lb and that is 4.5 kg of body fluids.
So, what other symptoms accompany a pitting edema? One is, if it is near a joint, then it may be difficult to move the joint because of the swelling, and another is the extremity may feel tight and sometimes numb with a tingling sensation. Cases also happen when an extremity is constricted by a cast or any tight object, the edematous part will eventually have poor blood circulation and can cause even more serious problems, locally. If there is a serious systemic medical condition, accompanying symptoms may range from difficulty breathing, chest pains, rales on the lungs upon auscultation and to heart murmurs. When these things happen, then a person must seek medical attention without delay.
In pregnant women, pitting edema can also happen as a clinical manifestation especially in the later trimester of pregnancy. If it is that harmless type (the one that doesn’t really show any concern) it may be because of the growing weight of the uterus that results to slight swelling of the lower extremities. Or, if it is in the later stage of pregnancy, it can be because during the last trimester the woman’s body will have to increase body fluids in preparation for a bigger loss of blood during delivery. However, if it is caused by a serious underlying condition, pregnant women have pitting edemas as a result of a pregnancy-induced hypertension such as pre-eclampsia and this has to be religiously managed as pregnancy-induced complication can put both the mother and the baby, at risk.
Pitting edema is measured by a certain grade based on its depth and duration. This is of course done to have initial data on the extent of the edema. The following information details how pitting edema is assessed:
- If pitting is equal, or less than 2mm and disappears rapidly then it is 1+
- If pitting is 2-4 mm and disappears in about 10-15 seconds, then it is 2+
- If pitting is 4-6 mm and disappears after more than 1 minute and dependent extremity look full then it is a 3+
- Lastly, if it is 6-8 mm and pitting may last more than 20 minutes and there is gross distortion on the extremity, then it is a 4+
It can also be graded according to the severity of the pitting manifested by both extremity (bilateral pitting edema)
- If both feet or ankles are edematous then it’s a 1+ (mild)
- If both feet are affected, lower legs, and hands, then it is a 2+ (moderate)
- If there is overall pitting edema which includes both feet, legs, arms and face then it is a 3 + (severe)
We may sometimes wonder (although, not at all times) on the types of fluids found inside an edematous tissue. These are categorized into three types: transudate, exudate, lymph. For transudate, it is usually poor in protein and barely without any distinguishable cells noted. In contrast to that, exudates are protein rich and have an amount of cellular structure present. For the lymphatic fluid it is usually protein rich. Both exudates and lymphatics do not cause pitting edema, only the transudates.
The questions on the causes of pitting edema will still lead us to the bigger umbrella on the causes of edema itself. People may have pitting edema and the risk factor is mostly because of diet and lifestyle such as eating too much salt, inactive lifestyle and extremity is immobile. But then again, it may be a result of a more serious health condition which includes cardiac failure, low levels of protein in the blood, insufficient venous circulation, liver illnesses, and drugs such as vasodilators and adnrogenic.
Furthermore, if it is a local edema it can probably cause obstruction of the vein, infection such as gout, and local trauma or injury such as bruise, sprain, fracture, insect bite, snake bite, frost bite, and burn. The most reliable measure of improvement when it comes to edema is body weight measurement, every day, and at the same time of the day, preferably done first thing in the morning. General management of edema includes bed rest, limiting of sodium intake, and administration of medications that allows excretion of excess body fluids through urination. With regards to skin care it is mostly focused on preventing further breakdown of the skin and preventing venous ulcers.
Author: Sarah Catina RN