What is Anasarca?
Anasarca is a severe, generalized form of edema characterized by profound swelling throughout the entire body, including the trunk, extremities, and face, resulting from excessive fluid accumulation in the interstitial spaces. 1
Clinical Features and Presentation
Anasarca presents with:
- Massive, generalized swelling affecting the entire body
- Significant weight gain (often 30+ pounds) over a short period 2
- Pitting edema when pressure is applied to swollen areas
- Skin stretching that may lead to blistering or desquamation in severe cases 3
- Respiratory distress due to fluid accumulation in lungs and pleural spaces 4, 5
- Scrotal and abdominal wall edema 5
- Functional limitations due to the extreme swelling
Pathophysiology
Anasarca develops when the normal fluid balance mechanisms fail, resulting in:
- Increased hydrostatic pressure - commonly from heart failure with fluid backing up in the venous system
- Decreased oncotic pressure - typically from hypoalbuminemia due to liver disease, malnutrition, or protein-losing conditions
- Increased capillary permeability - seen in inflammatory conditions
- Lymphatic obstruction - preventing normal fluid drainage
Underlying Causes
Anasarca is always a manifestation of an underlying condition:
Cardiac Causes
- Severe heart failure with reduced ejection fraction
- Right-sided heart failure
- Constrictive pericarditis
Renal Causes
- Nephrotic syndrome
- Severe renal failure
- Acute kidney injury
Hepatic Causes
- Cirrhosis with portal hypertension
- Severe hypoalbuminemia from liver dysfunction
Other Causes
- Severe protein malnutrition
- Protein-losing enteropathy
- Severe systemic inflammatory conditions
- Vasculitis 1
- Certain medications
- Advanced malignancy
Diagnostic Evaluation
Evaluation should focus on identifying the underlying cause:
- Comprehensive metabolic panel (liver and kidney function)
- Serum albumin levels
- Brain natriuretic peptide (BNP) for heart failure assessment
- Urinalysis for proteinuria
- Echocardiogram to assess cardiac function
- Abdominal ultrasound for liver assessment
- Chest imaging for pleural effusions 5
Clinical Significance and Complications
Anasarca is associated with:
- Respiratory compromise due to pleural effusions and pulmonary edema 4
- Impaired wound healing and skin breakdown
- Increased risk of infection in edematous tissues
- Reduced mobility and quality of life
- Higher postoperative complications after major surgeries 2
- Potential electrocardiographic changes due to altered electrical impedance 6
Management Approach
Treatment must address both the underlying cause and the fluid overload:
Treat the underlying condition:
- Heart failure management
- Renal replacement therapy if indicated
- Albumin replacement in severe hypoalbuminemia
- Immunosuppression for inflammatory conditions
Fluid removal strategies:
- Diuretic therapy (loop diuretics often at high doses)
- Salt restriction (<2g sodium daily)
- Fluid restriction when appropriate
- Dialysis or ultrafiltration in refractory cases
- Continuous flow peritoneal dialysis in severe pediatric cases 4
Supportive care:
- Elevation of extremities
- Compression garments when edema improves
- Skin care to prevent breakdown
- Respiratory support if needed
Prognosis
The prognosis of anasarca depends primarily on the underlying cause and the patient's response to treatment. Without intervention, anasarca can lead to significant morbidity including respiratory failure, skin breakdown, and reduced quality of life. In postoperative patients, anasarca is associated with higher complication rates and mortality 2.
Clinical Pearls
- Anasarca is always a sign of severe underlying disease, not a diagnosis itself
- The presence of elevated JVP improves the specificity of edema as a sign of congestion 1
- Patients should be at "target" or lower body weight compared to admission before discharge 1
- Anasarca can mask or alter other clinical findings, including electrocardiographic patterns 6
- Daily weight monitoring provides the most reliable measure of fluid status changes