๐Ÿงช Chapter 396: Pancreatic Function Tests

Nelson Textbook of Pediatrics 22nd Edition โ€” Pancreatic function tests assess exocrine pancreatic function. Direct tests: Secretin-CCK stimulation (gold standard) with duodenal aspirate for bicarbonate and enzymes; endoscopic collection. Indirect tests: Fecal elastase-1 (most common screening, unaffected by PERT), fecal fat (72-hour quantitative), serum trypsinogen, breath tests (13C-mixed triglyceride). Indicated for suspected pancreatic insufficiency (cystic fibrosis, Shwachman-Diamond, chronic pancreatitis).

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๐Ÿ“‹ 30 Clinical Scenarios โ€” Pancreatic Function Tests

๐Ÿ“‡ Highโ€‘Yield Review Cards (Pancreatic Function Tests)

๐Ÿฉบ Clinical Presentations: Pancreatic Insufficiency

Select a presentation for diagnostic clues and test selection.

๐Ÿ“‹ Stepwise Evaluation of Exocrine Pancreatic Function

๐Ÿ”‘ Key Principles โ€” Pancreatic Function Tests (Nelson Ch.396)
โ€ข Fecal elastase-1: Indirect test, not affected by PERT. Normal >200 ฮผg/g. 100-200 = moderate insufficiency, <100 = severe insufficiency. False-positive with watery stools.
โ€ข Fecal fat (72-hour): Gold standard for steatorrhea. Coefficient of fat absorption <93% = malabsorption. Requires diet record.
โ€ข Serum trypsinogen: Low in pancreatic insufficiency (CF, Shwachman-Diamond). Elevated in acute pancreatitis.
โ€ข Direct testing (secretin-CCK stimulation): Gold standard but invasive. Bicarbonate (<80 mEq/L) and enzyme output. Endoscopic pancreatic function test (ePFT).
โ€ข Breath tests: 13C-mixed triglyceride breath test (non-invasive, measures lipase activity).

    โšก Reflex Prompts โ€” Pancreatic Function Testing

    ๐Ÿ“– Pancreatic Function Tests โ€” Core Summary