Delayed Meconium Passage (Case 26)

Chapter 63 Delayed Meconium Passage (Case 26)

Jody Ross, MD

Case

A full-term infant at 36 hours of age who has not yet passed meconium develops difficulty feeding and abdominal distention.

Differential Diagnosis

Meconium ileus/meconium plug syndrome Hirschsprung disease
Small left colon syndrome Intestinal/anal malformations

Speaking Intelligently

Almost 99% of healthy infants pass meconium within 24 hours after birth, and 100% of healthy infants pass meconium by 48 hours of age. Therefore meconium retention past 24 hours may signal intestinal obstruction and necessitates a prompt evaluation. The evaluation must include the infant’s history and clinical examination as well as the maternal history, including drugs administered before and during labor. Radiographic studies, starting with plain abdominal radiographs, and consultation with a pediatric surgeon will usually be required.

Patient Care

Clinical Thinking

• Review the prenatal, peripartum, and family history.
• Provide prompt stabilization for the distressed infant.
• Evaluate the infant for signs of intestinal obstruction.
• Place a nasogastric tube in the vomiting infant.
• Review the most likely differential diagnoses given the patient’s history and physical examination.
• Consult with the pediatric surgeon, and systematically order radiographic studies.

History

• Review the infant’s prenatal course, maternal history, and family history.
• Inquire about drugs taken during pregnancy or labor, because illicit drugs and magnesium sulfate can interfere with meconium passage.
• Review the infant’s feeding history, especially the presence or absence of bilious vomiting.

Physical Examination

• Check vital signs: Tachycardia or bradycardia, weak pulses, and respiratory distress all indicate a distressed infant and the need for possible emergency surgery.
• Examine the infant with attention to the abdomen: Distention, visible dilated bowel loops, bowel sounds, position and patency of anus.
• Assess for dysmorphic features: 8% of patients with Hirschsprung disease have Down syndrome, and 70% of patients with anorectal malformations have other associated anomalies (vertebral defects, anorectal anomalies, cardiac defects, tracheoesophageal fistulas, renal defects, and radial upper limb hypoplasia, the VACTRL association).

Tests for Consideration

• Complete blood count (CBC): If concern for sepsis $116
• C-reactive protein: If concern for sepsis $69
• Blood culture: Sepsis can complicate neonatal bowel obstruction and cause delayed meconium passage $152
• Newborn screen for hypothyroidism and cystic fibrosis $227
• Electrolytes: Hypercalcemia and hypokalemia can cause ileus and delayed meconium passage. Electrolyte derangement and acidosis may also signal a surgical emergency (e.g., malrotation with volvulus) $174
• Anorectal manometry: If considering Hirschsprung disease $555
• Rectal suction biopsy: Demonstrates lack of ganglion cells for diagnostic confirmation of Hirschsprung disease $606

Imaging Considerations

→ Plain abdominal radiographs: A screen for obstruction—dilated loops, air fluid levels, stool retention $219

→ Contrast enema: To identify transition zone in Hirschsprung disease $530

→ Ultrasound: To delineate genitourinary anomalies associated with imperforate anus/anorectal atresia $563

→ Magnetic resonance imaging (MRI): Adjunct to evaluate spinal and genitourinary malformations associated with anorectal anomalies $1838

Related posts:

  1. The Special Needs Child
  2. Diarrhea (Case 6)
  3. Pediatric Poisonings (Case 54)
  4. Note Writing

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Jul 18, 2016 | Posted by in PEDIATRICS | Comments Off on Delayed Meconium Passage (Case 26)

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