A 45-year-old man with severe acute necrotising pancreatitis becomes hypotensive despite receiving 4 litres of crystalloid in 6 hours. His haematocrit rises from 38 to 50 percent. The physiological process responsible for his refractory hypotension is:

• A Renal sodium wasting caused by pancreatic kallikrein release
• B Sequestration of protein-rich fluid into the retroperitoneum and peritoneal cavity due to capillary leak ✓
• C Transcapillary refill pulling interstitial fluid into the vascular compartment
• D Excessive insensible losses through hyperventilation alone

Explanation

Pancreatic inflammation releases proteolytic enzymes and kinins that damage capillary endothelium, increasing permeability so that protein-rich exudate escapes into the retroperitoneum, peritoneum, and pleura. This 'third spacing' removes both volume and oncotic protein from the circulation, and rising haematocrit signals haemoconcentration from plasma loss. Transcapillary refill (option C) is the compensatory movement in haemorrhage, not the pathological process here.

Reference: Guyton and Hall Textbook of Medical Physiology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.