Approach to a patient with edema

Pathogenesis of Edema in malnourished

Exactly not known but it has been proposed that there is the diversion of fluid from capillary bed to interstitial space due to
1) Hypoalbuminemia ( Decreased oncotic pressure)
2) Increased capillary permeability
3) Increased hydrostatic pressure
3) Sodium and water retention
4) Lymphatic obstruction

Pathogenesis of Edema in hereditary angioedema

• The defect in the synthesis of normally functioning C1 inhibitor
• Uncontrolled C1 activity with the breakdown of C2 and C4 releasing vasoactive peptide (kinins)
• Vasodilation (increased hydrostatic pressure) leading to edema.

Differential Diagnosis

History

• Age – congenital lymphoedema
• Address/ traveling history- filariasis
• Site and distribution of edema
• Duration of the symptom

Associated symptoms should be asked-

• lethargy, dyspnoea,  PND, orthopnoea, cough, abdominal distention, edema first noticed over legs (cardiac disease)
• Jaundice, pruritus, abdominal distention, hematemesis, confusion (liver disease)
•  Generalized edema with peri-orbital puffiness, decreased urine output, frothy urine, cola-colored urine (renal disease)
• H/o sore throat, skin infection, joint pain to r/o RHD, Nephritic syndrome.
• H/o abdominal lump, swellings with weight loss may be associated with venous obstruction or lymphatic obstruction
• H/o chronic diarrhea, weight loss, and Steatorrhoea may be associated with malnutrition and protein-losing enteropathy.
• H/o fever may be associated with local or systemic infection.
• Dietary history- inquiry about breastfeeding, weaning time, type of food giving, weight gaining or not if inadequate associated with malnutrition
• Past h/o surgery and radiation may suggest lymphatic obstruction. Any past h/o jaundice, heart disease (including congenital) exclude known liver, heart disease.
• Family h/o recurrent angioedema may suggest hereditary angioedema.
• Treatment history– some drugs also cause edema e.g., nifedipine. Some drugs cause renal impairment and edema.
• H/o allergy to drug and other allergens.

Examination

General appearance- puffiness of the face, cachexic, toxic look.
R/o localized or generalized edema

Vital signs

Pallor, icterus, edema (site and distribution/ pitting or nonpitting), enlarged lymph node, cyanosis, clubbing.
Tenderness over edema site– DVT, Trauma, local infection
Anthropometric measurement – height, weight, MUAC-important for malabsorption and malnutrition
Daily abdominal girth (with pt’s with ascites) and weight measurement is important for monitoring of the patient
Engorged neck vein and jugular pressure, shifted apex beat, crepitations in the lung field, murmur and muffled heart sound on auscultation all show heart disease.
Dilated superficial abdominal veins, hepatomegaly and ascites are signs of liver disease.
Also look for abdominal mass that is obstructing the lymphatics or inferior vena cava.

Investigation

Urine analysis

CBC

Urea creatinine in renal failure
LFTs: Abnormal in liver disease
Serum albumin: with nephrotic syndrome, liver disease, malabsorption and malnutrition
Chest X-ray: cardiomegaly, pulmonary edema, pleural effusion

Specific investigation

• 24-hour urine collection> 40mg/m2/hour of protein with nephrotic syndrome
• Renal biopsy to determine the cause of nephrotic syndrome
• Echocardiography for ventricular dilation and impaired function with cardiac failure, valvular incompetence or stenosis, pericardial effusion can be seen
• Fecal fat estimation for malabsorption
• Doppler study of deep veins of legs to diagnose DV
• Venography to r/o IVC obstruction
• Lymphangiography to r/o lymphoedema

General Management

Basic approaches to the treatment of edema

1. Identify and treat the underlying disease. This is the mainstay of treatment of edema.
2. Decrease sodium and water intake, either dietary or intravenous. It will help not to worsen the disease rather than cure the disease.
3. Increase excretion of sodium and water
4. Diuretics – only some cases of generalized edema can be treated with diuretics and caution should be taken while using them. remember, these are palliative, not curative.
5. Bed rest, limb elevation local pressure
6. Do not make the disease worse treating vigorously with diuretics. treatment of edema is not usually an emergency