A patient with autoimmune hepatitis develops ascites. Laboratory workup shows serum albumin 2.2 g/dL. Which Starling force alteration predominantly drives hepatic ascites formation in hypoalbuminemia?
- A Increased hepatic sinusoidal hydrostatic pressure
- B Decreased plasma oncotic pressure reducing net capillary absorption ✓
- C Increased hepatic lymphatic flow exceeding thoracic duct capacity
- D Sodium and water retention from secondary hyperaldosteronism
Correct answer: B. Decreased plasma oncotic pressure reducing net capillary absorption
Explanation
Hypoalbuminemia (albumin < 2.5 g/dL) lowers plasma oncotic pressure (COP), reducing the absorptive Starling force at the capillary. Fluid accumulates in the interstitium and body cavities. While portal hypertension (option A) and secondary hyperaldosteronism (option D) also contribute to ascites in cirrhosis, the question specifies hypoalbuminemia as the primary driver. Option C is a consequence of altered Starling forces rather than a primary cause.
Reference: Guyton & Hall, Textbook of Medical Physiology, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.