The document outlines edema as a condition characterized by swelling due to the accumulation of interstitial fluid, triggered by factors such as increased capillary pressure or permeability, and lymphatic obstruction. Treatment focuses on addressing the underlying causes, dietary restrictions, supportive measures, and appropriate use of diuretics while monitoring for potential complications. Key points include careful management of fluid intake, especially in cases of severe hyponatremia, and the risks associated with overdiuresis in congestive heart failure.

1. APPROACH TO EDEMA
Presented by: Muhammad Wasil Khan
2018/066

3. Definition of Edema
• Soft tissue swelling due to abnormal
expansion of interstitial fluid volume.
• Edema fluid is a plasma transudate that
accumulates when movement of fluid from
vascular to interstitial space is favored.
• Since detectable generalized edema in the
adult reflects a gain of 3L, renal retention of
salt and water is necessary for edema to
occur.
• Distribution of edema can be an important
guide to cause.

7. Edema formation occurs when?
• An increase in capillary hydrostatic pressure (for example, increased
plasma volume due to renal sodium retention).
• An increase in capillary permeability (for example, burns,
angioedema).
• An increase in interstitial oncotic pressure (for example, myxedema).
• A decrease in plasma oncotic pressure (for example,
hypoalbuminemia).
• Lymphatic obstruction.

24. Treatment
• Primary management is to identify and treat the underlying cause of edema
• Dietary Na restriction (500 mg/d) may prevent further edema formation.
• Bed rest enhances response to salt restriction in CHF and cirrhosis. Supportive stockings
and elevation of edematous lower extremities will help mobilize interstitial fluid.
• If severe hyponatremia (132 mmol/L) is present,water intake should also be reduced
(1500 mL/d).
• Diuretics are indicated for marked peripheral edema, pulmonary edema, CHF, inadequate
dietary salt restriction.
• Weight loss by diuretics shouldbe limited to 1–1.5 kg/d. Distal (“potassium sparing”)
diuretics or metolazone may be added to loop diuretics for enhanced effect.
• Note that intestinal edema may impair absorption of oral diuretics and reduce
effectiveness. When desired weight is achieved, diuretic doses should be reduced.
• In CHF,avoid overdiuresis because it may bring a fall in cardiac output and prerenal
azotemia. Avoid diuretic-induced hypokalemia, which predisposes to digitalis toxicity.