A 3-day-old boy is seen in the nursery due to vomiting. He has had 2 episodes of nonprojectile vomiting of green fluid and has developed abdominal distension over the last hour. The patient is breastfed and initially nursed every 2 hours but is now nursing less frequently. The infant passed a small amount of meconium immediately after delivery but has passed no other stool. He is voiding adequately. The patient was delivered vaginally at 38 weeks gestation without complications. Apgars were 8 and 9 at 1 and 5 minutes, respectively. Temperature is 36.7 C (98 F). On examination, the infant is asleep but easily roused. The anterior fontanelle is open and flat, and the mucous membranes are moist. Cardiac examination is normal. The lungs are clear to auscultation bilaterally. The abdomen is distended with hypoactive bowel sounds. The liver and spleen are not palpable. Abdominal x-ray findings include dilated, gas-filled loops of small bowel; absent air-fluid levels; and a "ground-glass" mass in the right side of the abdomen. Further history-taking should focus on which of the following factors?

Question

A 3-day-old boy is seen in the nursery due to vomiting.  He has had 2 episodes of nonprojectile vomiting of green fluid and has developed abdominal distension over the last hour.  The patient is breastfed and initially nursed every 2 hours but is now nursing less frequently.  The infant passed a small amount of meconium immediately after delivery but has passed no other stool.  He is voiding adequately.  The patient was delivered vaginally at 38 weeks gestation without complications.  Apgars were 8 and 9 at 1 and 5 minutes, respectively.  Temperature is 36.7 C (98 F).  On examination, the infant is asleep but easily roused.  The anterior fontanelle is open and flat, and the mucous membranes are moist.  Cardiac examination is normal.  The lungs are clear to auscultation bilaterally.  The abdomen is distended with hypoactive bowel sounds.  The liver and spleen are not palpable.  Abdominal x-ray findings include dilated, gas-filled loops of small bowel; absent air-fluid levels; and a "ground-glass" mass in the right side of the abdomen.  Further history-taking should focus on which of the following factors?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c183_e63b_8f63_55a0aeaf554e_MD0005_00 Meconium ileus (MI) refers to intestinal obstruction of the distal ileum, classically seen in the neonatal period. It may be the earliest manifestation of cystic fibrosis (CF) and is virtually pathognomonic for the disorder. A mutation in the CF transmembrane conductance regulator results in inspissated gastrointestinal secretions that obstruct meconium excretion. Bilious emesis and abdominal distension may occur, and abdominal x-ray findings of dilated loops of small bowel, absent air-fluid levels, and a right-sided "ground-glass" mass (due to the mixing of air bubbles and meconium in the ileum) are suggestive of the diagnosis. abdominal x-ray Because CF is inherited in an autosomal recessive pattern, inquiring about a family history of recurrent sinus infections (or other manifestations of CF) is important to the diagnosis. Any infant with suspected MI should undergo sweat chloride or genetic testing. (Choice A) Family history of congenital cataracts would be expected with galactosemia, an autosomal recessive disorder caused by galactose-1-phosphate uridyltransferase deficiency. Dysfunctional galactose metabolism can cause vomiting and poor feeding, but lethargy, jaundice, and hepatomegaly would also be expected. (Choice C) In utero opioid exposure causes neonatal abstinence syndrome, defined by signs such as irritability, sleep disturbance, tremors, poor feeding, yawning, and diarrhea. Delayed passage of meconium is not associated. (Choice D) Advanced maternal age (≥35) increases the risk for Down syndrome, which is associated with duodenal atresia and Hirschsprung disease. Duodenal atresia is characterized by a double bubble (stomach and proximal duodenum) on abdominal x-ray and Hirschsprung disease by a markedly dilated descending colon. This patient's "ground-glass" mass is typical of MI. Duodenal atresia Hirschsprung disease (Choice E) Maternal macrolide use during pregnancy is a risk factor for pyloric stenosis, which typically presents around age 1 month with nonbilious, projectile vomiting. A palpable, "olive-shaped" abdominal mass is classic, and diagnostic ultrasound reveals a "target" sign (pyloric muscle hypertrophy), not a right-sided mass. Educational objective: Meconium ileus, characterized by intestinal obstruction of the distal ileum with meconium, is virtually pathognomonic for cystic fibrosis. A family history of recurrent sinus infections may be a clue for diagnosis. References: Prevalence of meconium ileus marks the severity of mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. (http://www.ncbi.nlm.nih.gov/pubmed/26087176)

A 3-Day-Old Boy Is Seen in the Nursery Due to Vomiting