From the Guidelines
Edema is the swelling of body tissues caused by excess fluid accumulation, which can result from various conditions including heart failure, kidney disease, liver problems, venous insufficiency, medication side effects, or prolonged sitting or standing. It occurs when fluid leaks from blood vessels into surrounding tissues, often appearing in the feet, ankles, legs, hands, or face. According to the study by 1, in patients with heart failure, peripheral oedema is usually associated with a high right atrial pressure that is most commonly due to left-sided heart failure.
Causes and Risk Factors
The causes of edema can be diverse, including:
- Heart failure
- Kidney disease
- Liver problems
- Venous insufficiency
- Medication side effects
- Prolonged sitting or standing As noted in the study by 1, risk factors for heart failure in patients treated with thiazolidinediones (TZDs) include history of heart failure, prior myocardial infarction, hypertension, left ventricular hypertrophy, significant aortic or mitral valve heart disease, advanced age, long-standing diabetes, preexisting edema, and current treatment with loop diuretics.
Treatment and Management
Treatment depends on the underlying cause but may include:
- Diuretics like furosemide (20-80mg daily) or hydrochlorothiazide (12.5-50mg daily) to remove excess fluid
- Reducing salt intake to less than 2,000mg daily
- Elevating affected limbs
- Wearing compression stockings
- Treating the primary condition For mild edema, lifestyle changes such as limiting salt, regular exercise, and avoiding long periods of immobility can help, as suggested by the study by 1.
Pathophysiology
Edema occurs because of increased hydrostatic pressure in blood vessels, decreased protein levels in blood (hypoalbuminemia), or increased vessel permeability, all of which disrupt the normal balance of forces that keep fluid within the bloodstream. The study by 1 highlights the importance of considering the risk of congestive heart failure in patients with diabetes who are treated with TZDs, as edema can be a sign of underlying heart disease.
Monitoring and Prevention
Monitoring patients on TZD therapy for weight gain or the presence of pedal edema is crucial, as edema can be a manifestation of congestive heart failure even in the absence of a prior history of heart disease, as noted in the study by 1. A noninvasive cardiac evaluation, including an ECG and echocardiogram, may be necessary to determine the underlying cause of edema.
From the Research
Definition of Edema
- Edema is defined as the abnormal collection of fluid in the tissues, which can occur in the interstitial or intracellular spaces 2.
- It results from excess accumulation of interstitial fluid, which may be due to increased transfer of fluid across the capillary membranes or excess retention of salt and water 3.
Causes of Edema
- Edema can arise as the result of an injury, acute illness or chronic condition 2.
- It can be caused by increased transfer of fluid across the capillary membranes or excess retention of salt and water, with the kidneys playing a significant role in promoting salt and water homeostasis 3.
- Congestive heart failure, liver cirrhosis, nephrotic syndrome, and renal failure are common underlying diseases that can cause edema 4.
Types of Edema
- Edema can be classified into different types, including generalized edema and localized edema, such as limb edema 5, 2.
- Refractory edema is a type of edema that is resistant to treatment, and may require combination therapy with diuretics and compression 6, 5.
Treatment of Edema
- The treatment of edema includes primarily the treatment of the underlying disease as well as sodium restriction 4.
- Diuretics are commonly used for the treatment of chronic heart failure, liver cirrhosis, nephrotic syndrome, and renal failure, and are effective in reducing edema 3, 4.
- Combination therapy with diuretics and compression may be effective in treating refractory edema 5.