Immediate Pediatric Surgical Referral
The most appropriate next step is B - Refer to pediatric surgery immediately, as this newborn presents with peritoneal signs (tenderness and absent bowel sounds) indicating a potential surgical emergency that requires urgent evaluation before any diagnostic procedures. 1
Clinical Rationale
This presentation represents a surgical emergency requiring immediate action:
The combination of absent bowel sounds with abdominal tenderness suggests peritonitis or bowel compromise, mandating immediate surgical evaluation before any diagnostic imaging. 1
The American College of Radiology explicitly recommends immediate pediatric surgical consultation for newborns with suspected intestinal obstruction, as 20% of neonates with bilious vomiting in the first 72 hours have midgut volvulus requiring urgent surgery. 1
Delayed meconium passage beyond 48 hours with abdominal distention is typical for distal bowel obstruction, which may require urgent surgical intervention. 1
Why Not the Other Options First?
Barium/Contrast Enema (Option A)
While contrast enema is the diagnostic imaging procedure of choice for suspected distal obstruction and can demonstrate microcolon in cases of distal atresia or meconium plug syndrome, imaging should not precede surgical consultation when peritoneal signs are present. 1
The American College of Radiology suggests that contrast enema may be appropriate after surgical evaluation and stabilization, not as the immediate next step. 1
Rectal Suction Biopsy (Option C)
- Rectal suction biopsy is indicated for diagnosing Hirschsprung disease, but this diagnostic procedure should not be performed before surgical evaluation in a neonate with acute peritoneal signs, as the clinical presentation suggests a more urgent surgical emergency requiring immediate intervention. 1
Critical Management Sequence
While awaiting surgical consultation, initiate supportive measures:
Nil per os (NPO) and intravenous fluid resuscitation to correct dehydration and electrolyte abnormalities should be initiated immediately. 1
Nasogastric tube decompression should be performed to decompress the stomach. 1, 2
Broad-spectrum antibiotics should be administered if peritonitis or necrotizing enterocolitis is suspected. 1
Blood gas and lactate levels should be assessed to evaluate for bowel ischemia, along with complete blood count, electrolytes, and renal function. 1
Critical Pitfall to Avoid
Never delay surgical consultation for imaging studies in a neonate with peritoneal signs, such as tenderness and absent bowel sounds, as this can lead to significant morbidity and mortality. 1 The absence of peritonitis does not exclude bowel ischemia, with physical examination having only 48% sensitivity for detecting strangulation. 1
Differential Considerations
This presentation is consistent with multiple surgical emergencies:
Midgut volvulus requires urgent surgery and can present identically to this case. 1
Jejunoileal atresia presents with failure to pass meconium, abdominal distension, and bilious vomiting. 3
Hirschsprung disease can present with delayed meconium passage and obstruction. 1
Necrotizing enterocolitis must be considered with peritoneal signs. 2
All of these conditions require surgical evaluation as the priority, with diagnostic studies performed after or in conjunction with surgical assessment based on the surgeon's judgment and the patient's stability.