Dr. Kaitlin Brooke presented an interesting global health case from her rotation in Botswana. The case was a middle age female who presented with subacute bilateral lower extremity edema and generalized weakness, who was found to have anasarca on exam with work up including labs and CXR concerning for nephrotic syndrome presumed secondary to secondary amyloidosis from chronic pulmonary TB. She was empirically treated for tuberculosis and received steroids for her nephrotic syndrome. Dr. Brooke shared many interesting facts about practicing medicine in a resource limited setting like Botswana!
We discussed the differential diagnosis of lower extremity edema by primary mechanism including:
- Increased plasma volume due to renal sodium retention (heart failure, nephrotic syndrome, drugs, pregnancy, etc.)
- Venous obstruction or insufficiency (cirrhosis or hepatic venous obstruction, acute pulmonary edema, local venous obstruction, etc.)
- Hypoalbuminemia (protein loss through nephrotic syndrome or protein-losing enteropathy or reduced albumin synthesis through liver disease or malnutrition)
- Increased capillary permeability (burns, trauma, inflammation or sepsis, allergic reactions, ARDS, diabetes, etc.)
Nephrotic syndrome is defined as proteinuria >3.5 g/d, hypoalbuminemia < 3.5 mg/dL, edema, and increased cholesterol. Etiology can be primary glomerular disease (FSGS, membranous nephropathy, minimal change disease, membranoproliferative GN) or due to systemic diseases (DM2, amyloidosis, SLE, cryoglobulinemia).
Dr. Brooke shared her workup of hypoalbuminemia in a resource limited setting detailed below.