Master the board step 3

Master the Boards: USMLE Step 3
Diaphragmatic Hernia
This presents as respiratory distress and scaphoid abdomen (distress related
to pulmonary hypoplasia).
Diagnostic Testing
Perform a chest x-ray to look for loops of bowel visible in the chest.
Treatment
Perform immediate intubation (may require extracorporeal membrane oxygenation),
followed by surgical correction.
Gastrointestinal and Hepatobiliary Disorders
Meconium Plugs (Lower Colon) and Meconium Ileus (Lower Ileum)
This presents initially with an intestinal obstruction. Associated conditions are
the following:
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Plugs:
--
Small left colon in IODM
--
Hirschsprung disease
--
Cystic fibrosis
--
Maternal drug abuse
··
Ileus: Cystic fibrosis
Diagnostic Testing
The best initial diagnostic test is an abdominal x-ray.
Treatment
Ileus with Gastografin enema.
Upper Gastrointestinal Malformation
VACTERL abnormalities are
the following:
• Vertebral defects
• Anal atresia
• Cardiac abnormalities
• Tracheoesophageal
fistula with Esophageal
atresia
• Radial and Renal
anomalies
• Limb syndrome
A newborn is born by normal vaginal delivery without complication. There is no
respiratory distress. Upon his first feed, he is noted to have prominent drooling;
he gags and develops respiratory distress. Chest x-ray reveals an infiltrate in the
lung. Which of the following will confirm the diagnosis?
a. Arterial blood gas
b. Blood cultures
c. CT scan of chest
d. Nasogastric tube placement
e. Gastrografin enema
Answer: D. This patient has a tracheoesophageal fistula (TEF). Classically, there is
choking and gagging with the first feeding and then respiratory distress develops due
to aspiration pneumonia. The feeding tube will be coiled in the chest. Don’t forget to
look for other abnormalities associated with VACTERL syndrome.
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