Recognizing and diagnosing pancreatic insufficiency in infants.

Abstract

1. Peter Francis Belamarich, MD 1. Einstein College of Medicine-Children’s Hospital at Montefiore Bronx, NY 1. Exocrine Pancreatic Dysfunction. Cystic Fibrosis. Gaskin K. In: Walker WA, Durie PR, Hamilton JR, Walker-Smith JA, Watkins JB, eds.Pediatric Gastrointestinal Disease, Hamilton, Ontario, Canada: BC Decker Inc;.2000;:1353–1369 2. Pancreatic Function Tests. Huynh H, Couper R. In: Walker WA, Durie PR, Hamilton JR, Walker-Smith JA, Watkins JB, eds.Pediatric Gastrointestinal Disease, Hamilton, Ontario, Canada: BC Decker Inc.2000;:1515–1528 3. Hereditary and Childhood Disorders of the Pancreas. Lopez MJ, Grand RJ. In: Feldman MH, Sleisenger MH, Scharschmidt BF, eds.Sleisenger and Fordtran’s Gastrointestinal and Liver Disease Philadelphia, Pa: WB Saunders.1998;:782–808 Pancreatic insufficiency (PI) is uncommon among infants, but it is important to recognize. Early diagnosis followed by oral enzyme replacement therapy can avert the significant morbidity that follows upon severe malnutrition in infancy. In addition, for the majority of infants who have PI and subsequently are found to have cystic fibrosis, early diagnosis allows genetic counseling to be offered and can help prevent progression of associated pulmonary disease. The pathophysiology of pancreatic insufficiency is complex. Malabsorption results from inadequate secretion of the approximately 20 enzymes and cofactors derived from the pancreatic acini as well as from insufficient bicarbonate secretion from the ductal epithelium. Without adequate bicarbonate to neutralize gastric acid, whatever limited pancreatic lipase is available cannot function optimally, and bile salt micellization of dietary fat droplets also is impaired. Thus, fat digestion takes a “double hit,” and fat malabsorption becomes a prominent clinical feature of PI. Protein maldigestion and malabsorption are also substantial, but they are more commonly subclinical. Quantitative studies of pancreatic enzyme secretion have shown that the pancreas has a tremendous functional reserve. Significant fat malabsorption does not occur until lipase secretion is below 2% of normal values. Thus, clinically apparent PI represents not mild or …