A 2-day-old boy develops abdominal distension and refuses to breastfeed. He was born via normal spontaneous vaginal delivery at 39 weeks gestation to a primigravid mother. Examination shows significant abdominal distension with palpable intestinal loops. The rectum has no stool and rectal tone is normal. During the examination, the infant has several episodes of dark green emesis. Plain films of the abdomen show air-fluid levels and small bowel dilation. Contrast enema fails to relieve the obstruction, and the patient is taken for emergency laparotomy, which shows an inspissated, green fecal mass obstructing the distal ileum. The infant recovers from the surgery uneventfully. Which of the following will be the most likely cause of mortality in this patient?

Question

A 2-day-old boy develops abdominal distension and refuses to breastfeed.  He was born via normal spontaneous vaginal delivery at 39 weeks gestation to a primigravid mother.  Examination shows significant abdominal distension with palpable intestinal loops.  The rectum has no stool and rectal tone is normal.  During the examination, the infant has several episodes of dark green emesis.  Plain films of the abdomen show air-fluid levels and small bowel dilation.  Contrast enema fails to relieve the obstruction, and the patient is taken for emergency laparotomy, which shows an inspissated, green fecal mass obstructing the distal ileum.  The infant recovers from the surgery uneventfully.  Which of the following will be the most likely cause of mortality in this patient?

Quizplus · Accepted Answer

11ec160b_3a0b_40da_9249_ad9ec38591bb_MD0001_00 This patient's abdominal distension, bilious emesis, and x-ray findings (air-fluid levels, small bowel dilation) are consistent with bowel obstruction. The intraoperative finding of a green inspissated mass (dehydrated meconium) in the distal ileum points to the diagnosis of meconium ileus as the source of obstruction. Meconium ileus is a very specific finding for cystic fibrosis (CF). Although only 10%-20% of infants with CF will have meconium ileus at birth, almost all full-term infants with meconium ileus are eventually diagnosed with CF. Abnormalities in chloride, sodium, and water transport by the ductal epithelium of intestinal mucous glands cause isotonic dehydration of the lumen contents. This results in secretion of abnormally viscous mucus into the small bowel. In the United States, pneumonia, bronchiectasis, and cor pulmonale account for most deaths due to CF. (Choice A) Patients with Hirschsprung disease (HD) typically present with signs of intestinal obstruction in the newborn period that are similar to meconium ileus. However, HD typically presents with increased rectal tone, "squirt sign" (forceful expulsion of stool after rectal examination), and obstruction at the rectosigmoid region with a transition zone between the aganglionic rectum and proximal dilated colon. Enterocolitis (diarrhea, abdominal pain/distension, and fever) is the most common cause of mortality in patients with HD. (Choice B) Focal biliary or multilobular cirrhosis due to plugging of bile canaliculi by dehydrated mucinous material develops in approximately 5% of CF patients. Death from cirrhotic liver failure is much less likely than terminal pneumonia. (Choice C) Most patients with CF have exocrine pancreatic insufficiency, which causes malabsorption and steatorrhea. Infants often have large foul-smelling stools, abdominal distention, and poor weight gain. Consequences include deficiencies of fat-soluble vitamins, hypoproteinemia with generalized edema, and persistent diarrhea with rectal prolapse. However, pancreatic involvement is rarely fatal with pancreatic enzyme supplementation. (Choice E) Although the CFTR protein is expressed in nephrons, patients with CF usually do not manifest serious renal dysfunction or failure. Patients with CF, however, are at elevated risk for nephrolithiasis and renal damage from nephrotoxic medications (eg, aminoglycosides). Educational objective: Meconium ileus is a distal small bowel obstruction due to abnormally dehydrated meconium in a patient with cystic fibrosis (CF). Persistent, treatment-resistant infectious pneumonias, bronchiectasis, and cor pulmonale account for most deaths due to CF. __________ References: Gastrointestinal Manifestations of Cystic Fibrosis. (http://www.ncbi.nlm.nih.gov/pubmed/25648641) Cystic fibrosis. (http://www.ncbi.nlm.nih.gov/pubmed/19403164) Neonatal bowel obstruction. (http://www.ncbi.nlm.nih.gov/pubmed/22595716)

A 2-Day-Old Boy Develops Abdominal Distension and Refuses to Breastfeed