Those spaces in between!
Interstitial spaces are small narrow spaces in between tissues of the body. Flowing along those spaces are fluids that are responsible for bathing those cells and tissues with nutrients and other chemicals. The volume of fluid in the interstitial spaces are basically regulated by pressure exerted by the body fluid at equilibrium at a certain point within the fluid (hydrostatic pressure) and the pressure exerted by proteins specifically albumins found in the plasma of blood (oncotic pressure). The fluid is constantly in motion and continuously refreshed by the blood capillaries and collected back through the lymphatic capillaries. In an average a 70 kg male, the volume of fluid in the interstitial space is 10.5 liters.
When balance is disturbed
However, there are some instances or body conditions that disrupts the equilibrium between collection and or replenishment of these interstitial fluids and this results to the increased hydrostatic pressure in the capillaries, increase volume of the plasma, decreased oncotic pressure in cases of decreased protein molecules in the body, and or obstruction in the lymphatic system. This condition is characterized by the swelling within or under the skin. It can be described as pitting edema, where there is indentation when a finger is pressed down on the edematous area, or there is the non-pitting edema, when skin springs back after finger is pressed down.
Depending on its location and anatomical structure, edematous areas may become tense but more often, edema is soft and can easily be compressed when palpated. If the edematous area is red and warm, then infection should be suspected. The areas where this condition is mostly observable are on the lips, eye area and the areas in the cheekbone. Sometimes superficial products place beneath the skin can cause edema like when injected with specific medications or when fillers are in placed. There are delayed facial edema that may develop several days to weeks after certain procedure, which can cause allergic reaction (type IV hypersensitivity reaction).
Furthermore, edema can either be systemic or localized. Systemic edema is caused by cardiac disease, hepatic disease and allergic reaction, while localized edema may be caused by long term insufficiency of venous circulation, deep vein thrombosis and lymphedema. When there is edema caused by venous insufficiency, (dependent edema) which is very observable on the lower extremities, this is more likely to improve when the extremity is elevated. Edema, however, that is caused by liver failure, nephrotic syndrome, etc. does not change whether the legs are elevated or dependent.
When pitting edema occurs due to a deep vein thrombosis (DVT), it is usually painful upon palpation. In contrast to that, lymphedema usually does not elicit pain when palpated. Color changes on the skin, and temperature changes most of the time provide data on the cause of edema. In DVT and cellulitis, the affected area is usually warm. In chronic venous insufficiency the skin color is usually reddish and brawny. The most common cause of leg edema in individuals above 50 years of age is venous insufficiency and it affects approximately half of the population among the age group, while heart failure only affects 1%. Among women, the most common is idiopathic edema when under the age of 50 years old.
Proper assessment and physical examination is essential
History taking is very important when understanding the case. It should include the time duration of edema and time it started. It should be determined if changes in position will also change the characteristic of the edematous areas, as well as medication history of the individual. Sudden swelling of an extremity less than 72 hours can be more characterized as a result of a deep vein thrombosis, cellulitis, ruptured popliteal cyst, acute compartment syndrome from an injury, or initiation of medications such calcium channel blockers. However, the long-term development of a generalized edema might probably due to the flaring of chronic system conditions, such as congestive heart failure, kidney conditions, or liver diseases.
How is edema managed?
Edema occurring less than 2 weeks can be managed as expected. Although ice packs have not been accepted to reduce the swelling, many leading practitioners continue to encourage these in addition to warm compresses to decrease redness, edema, and pain. Gentle massage is also good to encourage lymphatic drainage. Appropriate follow-up and close observation may be enough.
When edema is more than 2 weeks long, it is very important to determine the cause of the swelling rather than treating the swelling itself. Allergic reaction for example can cause edematous conditions in cases like fillers and implants. Cases such as this may not respond well to antihistamines only, but has to be managed with oral steroids. However, since long term use of steroids can also bring harm to the body, the best course of action then is to remove the underlying cause, such as in cases with fillers. If there are no remaining options in treating edema, medications will have to be administered like diuretics. Diuretics allows elimination of excess fluids through urination.
An individual should bear in mind that in any cases of edema, medical attention should be sought. There are a lot of reasons why edema occurs. Some may not be harmful as seen but it can be caused a serious underlying health condition.
Author: Sarah Catina RN