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Difficulty: HardNeonatal Disorders

A 14-day-old male infant is evaluated in the neonatal intensive care unit for acute clinical deterioration. He was born at 26 weeks gestation via emergency cesarean delivery for maternal severe preeclampsia. Birth weight was 850 g (1 lb 14 oz). Apgar scores were 4 and 6 at 1 and 5 minutes, respectively. Two days ago, the infant developed feeding intolerance, abdominal distension, and grossly bloody stools. An abdominal radiograph demonstrated pneumatosis intestinalis. He was made nil per os (NPO) and started on gastric decompression, intravenous fluids, and broad-spectrum antibiotics (ampicillin, gentamicin, and metronidazole).

Over the past 2 hours, the infant has become increasingly lethargic. His temperature is 35.4°C (95.7°F), heart rate is 190/min, respiratory rate is 70/min, and blood pressure is 38/20 mmHg. He requires endotracheal intubation for escalating apneic episodes and hypoxia. Physical examination reveals a tense, rigid abdomen with marked erythema of the abdominal wall. A stat anteroposterior supine abdominal radiograph demonstrates prominent linear radiolucencies within the bowel wall and a new, large, continuous radiolucent shadow centrally that outlines the falciform ligament.

Which of the following is the most appropriate next step in the management of this patient?

  1. Exploratory laparotomyAnswer
  2. B
    Continuation of current medical management and serial abdominal radiographs
  3. C
    Escalation of antimicrobial therapy to include intravenous vancomycin and fluconazole
  4. D
    Computed tomography scan of the abdomen without contrast
  5. E
    Reassurance and observation for a presumed transient neonatal skin eruption

Answer

Exploratory laparotomy
The correct answer is exploratory laparotomy. This premature infant initially presented with medical necrotizing enterocolitis (NEC), characterized by bloody stools and pneumatosis intestinalis. His acute deterioration, marked by septic shock (hypotension, hypothermia) and abdominal wall erythema, signals progression to severe necrotic bowel. Crucially, the new radiographic finding—a central continuous radiolucent shadow outlining the falciform ligament—is known as the 'football sign.' In a supine neonate, air rises to the anterior abdomen, and massive free air (pneumoperitoneum) outlines the falciform ligament. Pneumoperitoneum indicates a full-thickness bowel perforation, which is an absolute indication for immediate surgical intervention (exploratory laparotomy or primary peritoneal drainage).

Step-by-Step Solution

1
Identify the primary diagnosis based on the initial presentation.
The history of prematurity, feeding intolerance, bloody stools, and pneumatosis intestinalis confirms a baseline diagnosis of necrotizing enterocolitis (NEC).
Establishing the underlying pathophysiology is necessary to contextualize the patient's acute deterioration.
2
Analyze the acute clinical changes and vital signs.
The infant has developed hypothermia, severe hypotension, tachycardia, and respiratory failure requiring intubation, indicating the onset of septic shock.
Hemodynamic instability strongly suggests disease progression and failure of the initial medical management.
3
Interpret the physical exam findings and the repeat abdominal radiograph.
Abdominal wall erythema suggests severely necrotic bowel. The distinct radiolucent outline of the falciform ligament (the 'football sign') is diagnostic of massive pneumoperitoneum.
Accurate interpretation of this specific imaging sign establishes the presence of a full-thickness bowel perforation.
4
Determine the appropriate management protocol.
Bowel perforation in the setting of NEC is an absolute indication for immediate surgical intervention.
Medical management cannot treat a free intestinal perforation; surgical source control via laparotomy (or primary peritoneal drainage) is required to prevent death.

Key Concept

Surgical indications in Neonatal Necrotizing Enterocolitis (NEC)
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Topics

Neonatal Disorders

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