Generalized edema

Rationale

Generalized edema is systemic palpable soft tissue swelling produced by expansion of the interstitial fluid volume. This condition may be caused by serious underlying disease and can be life-threatening.

Causal Conditions

(list not exhaustive)

1. Increased capillary hydrostatic pressure
   1. Increased plasma volume due to renal sodium retention
      1. Heart failure
      2. Reduced systemic vascular resistance (e.g., cirrhosis)
      3. Primary renal sodium retention (e.g., renal disease, drugs)
      4. Pregnancy
      5. Premenstrual edema
   2. Decreased arteriolar resistance (e.g., calcium channel blockers, idiopathic)
2. Decreased oncotic pressure (hypoalbuminemia)
   1. Protein loss (e.g., nephrotic syndrome)
   2. Reduced albumin synthesis (e.g., liver disease, malnutrition)
3. Increased capillary permeability (e.g., burns, inflammation)
4. Increased interstitial oncotic pressure (e.g., myxedema)

Key Objectives

Given a patient with generalized edema, the candidate will diagnose the cause, severity, and complications, and will initiate an appropriate management plan. In particular, it is important to differentiate systemic edema from local edema and categorize the general mechanism of edema, since management may be affected.

Enabling Objectives

Given a patient with generalized edema, the candidate will

1. list and interpret critical clinical findings, including those derived from an appropriate history and physical examination;
2. list and interpret critical investigations (e.g., creatinine level, urinalysis, chest radiography);
3. construct an effective initial management plan, including
   1. nonpharmacologic measures (e.g., dietary salt restriction),
   2. pharmacological measures, and
   3. determination as to whether the patient requires specialized care and/or consultation (e.g., patient with advanced renal, cardiac, or hepatic disease).