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Difficulty: Very hardPediatric Gastrointestinal Disorders

A 2-day-old male neonate is evaluated in the neonatal intensive care unit after two episodes of bilious emesis. He was born at 38 weeks gestation via uncomplicated spontaneous vaginal delivery to a 29-year-old primigravida. Prenatal ultrasonography at 32 weeks revealed polyhydramnios. His temperature is 37.1°C (98.8°F), heart rate is 145/min, blood pressure is 65/40 mm Hg, and respiratory rate is 42/min. Physical examination reveals a soft, non-distended abdomen without guarding, rigidity, or erythema of the abdominal wall. Bowel sounds are decreased. A nasogastric tube is placed, returning 25 mL of dark green fluid. An anteroposterior abdominal radiograph demonstrates a distended stomach and proximal duodenum (double bubble sign), along with a small amount of scattered gas in the distal small and large bowels. There is no pneumatosis intestinalis or free intraperitoneal air. Which of the following is the most appropriate next step in management?

  1. A
    Echocardiography
  2. B
    Emergent exploratory laparotomy
  3. Upper gastrointestinal contrast seriesAnswer
  4. D
    Water-soluble contrast enema
  5. E
    Abdominal ultrasonography

Answer

The most appropriate next step in management is an upper gastrointestinal contrast series.
The neonate presents with bilious emesis, a cardinal sign of neonatal bowel obstruction. The initial abdominal radiograph demonstrates a distended stomach and proximal duodenum, often referred to as a 'double bubble' sign. Crucially, there is a small amount of gas in the distal bowel. A double bubble sign WITHOUT distal gas is the classic presentation of complete duodenal obstruction, most commonly duodenal atresia. However, the presence of distal gas indicates a partial obstruction. In this scenario, malrotation with midgut volvulus is the most life-threatening diagnosis and must be ruled out immediately. Because the patient is hemodynamically stable with a benign abdominal examination, the most appropriate next step is an upper gastrointestinal (UGI) contrast series. The UGI series is the gold standard for diagnosing malrotation, classically demonstrating an abnormally positioned ligament of Treitz on the right side of the abdomen and a 'corkscrew' appearance of the duodenum if volvulus is present.

Step-by-Step Solution

1
Analyze the patient's primary symptom and immediate initial management.
The neonate has bilious emesis, a critical red flag for neonatal intestinal obstruction. The team correctly initiated stabilization with nasogastric tube decompression.
Bilious emesis in a neonate must be considered a surgical emergency until proven otherwise, specifically mandating evaluation for midgut volvulus.
2
Interpret the specific findings on the abdominal radiograph.
The X-ray shows a 'double bubble' sign WITH scattered distal gas. It lacks free air or pneumatosis intestinalis.
A classic double bubble WITHOUT distal gas indicates complete duodenal obstruction (e.g., duodenal atresia). The presence of any distal gas indicates a partial obstruction, keeping malrotation as a highly probable differential.
3
Determine the optimal diagnostic pathway based on the imaging and clinical stability.
Because the obstruction is partial and the patient is hemodynamically stable, emergent definitive imaging is required to rule out malrotation with midgut volvulus.
An upper gastrointestinal (UGI) contrast series is the gold standard. It will demonstrate the abnormal position of the ligament of Treitz and a potential 'corkscrew' sign if volvulus has occurred.
4
Exclude premature or incorrect interventions.
Immediate laparotomy is bypassed due to patient stability. Echocardiography is bypassed because ruling out volvulus takes precedence over syndromic workup.
Proper sequencing prevents unnecessary surgeries and ensures life-threatening conditions are excluded before focusing on congenital associations.

Key Concept

In a neonate with bilious emesis, an abdominal radiograph showing a double bubble WITH distal gas indicates a partial obstruction, requiring an emergent upper GI series to definitively rule out malrotation with midgut volvulus.
Estimated Time:1m 30s
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Topics

Pediatric Gastrointestinal Disorders

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