A patient with nephrotic syndrome has massive edemata of his face and limbs. What is the leading pathogenetic mechanism of edemata development?

Answer options

1. Increase of lymph outflow
2. Lymphostasis
3. Rise of hydrodynamic blood pressure
4. Drop of oncotic blood pressure
5. Increase of vascular permeability

Explanation

Nephrotic syndrome is characterized by large amounts of proteinuria (>3.5g/l), hypoalbuminemia (< 2,5 g/dl), hyperlipidemia, and edema that begins in the face. Lipiduria (lipids in urine) can also occur. The oncotic pressure is mainly controlled by plasma proteins and the major protein in plasma is albumin. Therefore, reduced protein content leads to edema due to its excretion. Reduced proteins mean a drop in oncotic pressure.