Chapter 38: Gastrointestinal Obstruction

SCOPE

DISEASE/CONDITION(S)

Diagnosis and treatment of neonates with symptoms of gastrointestinal obstruction.

GUIDELINE OBJECTIVE(S)

The objectives of this chapter are to review the symptoms of neonatal gastrointestinal obstruction, describe diagnostic approaches to the neonate with symptoms of gastrointestinal obstruction, and identify treatment options for infants with gastrointestinal obstruction.

BRIEF BACKGROUND

Gastrointestinal obstruction is a common reason for neonatal intensive care. The overall incidence of gastrointestinal obstruction is approximately 1:2000. Early symptoms of gastrointestinal obstruction include nonbilious or bilious emesis, abdominal distention, and failure to pass meconium. Left unrecognized, the sequelae of gastrointestinal obstruction can be life threatening and include sepsis, shock, and necrosis of significant portions of bowel. Early recognition and treatment can prevent lifelong complications and death.

SCOPE

DISEASE/CONDITION(S)

Pyloric stenosis.

GUIDELINE OBJECTIVE(S)

To identify and review diagnostic approaches to and pre- and postoperative management of pyloric stenosis.

BRIEF BACKGROUND

Epidemiology

The incidence of pyloric stenosis varies based on geographic location with rates of 2–5/1000 live births in the Western world and decreased incidence in Asian and African populations. There is a male predominance with a male:female ratio of 4–5:1.

Pathophysiology

The etiology of pyloric stenosis is poorly understood and considered to be multifactorial, with a combination of environmental and genetic factors playing a role.

There appears to be abnormal innervation of the pylorus making the muscle unable to relax, leading to increased synthesis of growth factors and hypertrophy of the muscle.

Bottle-fed infants have an increased risk of developing pyloric stenosis compared to breastfed infants, with the theory that breast milk contains vasoactive intestinal peptide which serves to relax the pylorus.

Macrolide antibiotics, specifically erythromycin, have been associated with the development of pyloric stenosis by serving as motilin agonists.

The genetic etiology behind the development of pyloric stenosis is poorly understood but may involve single-nucleotide polymorphisms (SNPs) regulating the production of nitric oxide, as well as other SNPs which have been identified in genome-wide association studies.

Presentation

Infants usually present between 3 weeks and 3 months of age with non-bilious, projectile vomiting.

Because the hypertrophied pylorus will prevent bile reflux into the stomach, bilious emesis should prompt urgent evaluation for other intestinal obstruction.

Pathognomonic acid-base and electrolyte abnormalities include a hypochloremic, hypokalemic metabolic alkalosis; however, many infants may present with normal laboratory values.

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Diagnosis

History of vomiting and physical examination ...