Edema

Definition

Edema is an abnormal accumulation of interstitial fluid causing tissue swelling. It may be localized or generalized and has diverse etiologies.

Types

• Pitting edema: Indentation remains after pressure; graded 1+ (slight) to 4+ (deep, >2 cm, persistent).
• Non-pitting: Lymphedema, myxedema.
• Dependent: Lower extremities in ambulatory patients, sacrum in bedridden.
• Generalized (anasarca): Severe systemic fluid overload.

Mechanisms

Increased hydrostatic pressure (CHF, venous insufficiency), decreased oncotic pressure (hypoalbuminemia from cirrhosis or nephrotic syndrome), lymphatic obstruction (cancer, post-mastectomy), and increased capillary permeability (burns, sepsis, allergy).

Nursing Interventions

Assess location, severity (grade), and symmetry. Elevate extremities, apply compression stockings, restrict sodium and fluid as ordered, administer diuretics, monitor daily weight and I&O, protect skin. Measure abdominal girth for ascites.

NCLEX Relevance

Pitting edema scale is high-yield. Daily weight is the most accurate fluid measure.