One of the key manifestations of physical or biochemical insult to the human body is edema (swelling within and around its tissues). During wound care, edema should be taken seriously as it usually indicates a negative pathological state. As untreated edema can slow tissue healing, wound care experts must recognize the risk factors and institute appropriate management plans. 

Defining Edema

Edema can be defined as the presence of excess body fluid within or around body cells or tissues which manifests physically as swelling. Edema occurs due to the movement of excess interstitial fluid to the space between the cells that compose various body tissues. Failure of the body’s natural fluid drainage mechanism to clear the excess fluid will result in worsening body swelling. 

While edema can affect almost anyone, people who experience trauma, burn wounds, or have chronic medical conditions, such as hypertension, are more susceptible to developing significant body swelling. Additionally, pregnancy can cause edema which usually resolves after childbirth.

Types of Edema?

Edema can be categorized according to the part of the body which it affects.

• Peripheral edema
• Pleural edema
• Pulmonary edema
• Cerebral edema
• Anasarca (massive and widespread edema)

Depending on the presence or absence of an underlying medical condition, patients with acute or chronic wounds will develop edema around or within the wound site which can inhibit optimal healing. Wound site edema is a form of peripheral edema as the extremities (upper and lower limbs) are the most commonly affected areas. 

Risk Factors

Edema can be caused by any intrinsic or extrinsic factors that alter the equilibrium between the production and drainage of interstitial fluids. Burns, surgical and other sources of tissue trauma, chronic medical diseases can all alter interstitial fluid dynamics and result in edema. 

The risk factors for edema include:

• Trauma
• Surgery
• Chronic wounds
• Persistently elevated blood pressure levels
• Heart failure
• Kidney disease
• Chronic venous insufficiency
• Severe protein deficiency
• Lymphatic system defects
• Insect bites and stings
• Drugs (e.g., steroids, anti-hypertensive medication, estrogen, and oral hypoglycemic agents)

Clinical Signs and Symptoms

Edema will manifest physically as swelling or enlargement of the affected body area. Listed below are common presentations of tissue edema.

• Puffy and swollen skin
• Taut skin with a shiny appearance
• Shortness of breath
• Chest pain  
• Breathing difficulties
• Rapid and significant weight gain
• Increased difficulty in moving about
• Retention of depressions on skin indentation

Diagnosis of Edema

The diagnosis of edema is usually done clinically. The presence of suggestive clinical signs, and symptoms, coupled with an exhaustive history, and physical examination is usually sufficient to clinch the diagnosis. However, the use of radiological investigative approaches such as MRI or CT scanning, X-rays, ultrasonography, and lymphangiography will boost diagnostic accuracy. 

Effects of Edema on Wound Healing

Persistent tissue swelling within and around a healing wound is detrimental to a smooth repair process. Edema can cause significant pain at the wound site, discouraging limb mobility that improves circulation to the site. Edema fluid can also serve as a medium for the proliferation of bacteria and other microorganisms leading to wound infection, and tissue breakdown. Further, the seepage of excess fluid into the spaces between cells can increase the pressure on small blood vessels in that area destroying them and causing local tissue necrosis.

Treatment of Edema

Different treatment approaches exist in the management of edema. The most effective strategies include:

• Medication use
• Exercise and ambulation
• Elevation of edematous area
• Compression wear
• Control of chronic medical conditions

Medication Use

The pharmacological properties of the following drug classes can be harnessed to treat different forms of edema.

• Analgesia
• Anti-inflammatory drugs
• Anti-histamines
• Diuretics

Analgesia

Pain presents an immediate concern in patients with edema and the use of mild opioid analgesia or Non-steroidal anti-inflammatory drugs (NSAIDs), will help address this symptom.

Antihistamines

Antihistamines can be used to treat edema resulting from allergies. These medications will stabilize the affected cells, preventing further release of pro-inflammatory chemical mediators. 

Diuretics

Diuretics are medications that can reduce edema by pulling excess fluid from the affected tissues and excreting it as urine. These drugs are particularly beneficial in patients with underlying medical conditions like a cardiac failure or renal disease.

Exercise and Ambulation

Patients with edema should be encouraged to do mild to moderate workouts and ambulate as often as possible. Regular exercise and ambulation will improve venous circulation in affected areas and allow the improved lymphatic drainage of excess fluids. 

Elevation of Edematous Area

Limb elevation can reduce pressure on dependent body areas like the lower limbs where fluid can easily pool. Wound care professionals should counsel patients on the benefits of intermittent limb elevation and rest as a treatment strategy for edema.

Compression Wear

Wound care providers can provide affected patients with compression socks, sleeves, or gloves which help to limit the development of further edema. These devices can be used at an advanced stage of treatment to prevent re-accumulation of fluid within dependent areas.

Control of Chronic Medical Conditions

Adequate management of chronic medical conditions that predispose patients to edema is a crucial aspect of treatment. Medical control of underlying diseases like diabetes, hypertension, and arterial or venous disease will significantly reduce tissue edema.