What is the best next step in managing a 2-week-old premature girl with increasing episodes of apnea and bradycardia, lethargy, mild abdominal distension, and normal vital signs, aside from tachycardia and tachypnea?

From the Guidelines

The best next step in management for this 2-week-old premature infant with increasing apnea and bradycardia episodes is an abdominal x-ray (option A). This infant presents with concerning symptoms including lethargy and mild abdominal distension, which in a premature infant receiving enteral feeds raises suspicion for necrotizing enterocolitis (NEC). NEC is a serious gastrointestinal emergency in premature infants that can present with apnea, bradycardia, lethargy, and abdominal distension.

• Key symptoms that point towards NEC include:
  • Apnea
  • Bradycardia
  • Lethargy
  • Abdominal distension An abdominal x-ray would help identify pneumatosis intestinalis (air in the bowel wall), portal venous gas, or pneumoperitoneum, which are radiographic findings consistent with NEC.
• The importance of early diagnosis is highlighted by the potential for serious complications such as intestinal perforation, sepsis, and death if left untreated 1. The infant's clinical presentation doesn't suggest primary cardiac or respiratory failure requiring immediate intubation or echocardiography.
• According to the 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care, medications such as epinephrine are rarely indicated in the resuscitation of newly born infants, and the focus should be on establishing adequate ventilation 1. Metoclopramide would not address the underlying concern for NEC, and simple observation would be inappropriate given the concerning symptoms in this high-risk patient.
• Early diagnosis of NEC through appropriate imaging is crucial as it allows for prompt intervention, including bowel rest, antibiotics, and surgical consultation if needed.

From the Research

Clinical Presentation

The patient is a 2-week-old girl in the neonatal intensive care unit for prematurity, presenting with increasing episodes of apnea and bradycardia over the past 3 hours. She was born at 29 weeks gestation via vaginal delivery, with a birth weight of 1.02 kg (2 lb 4 oz). The patient has been receiving enteral feeds via nasogastric tube with premature formula.

Key Findings

• Temperature: 36.1 C (97 F)
• Blood pressure: 76/42 mm Hg
• Pulse: 150/min
• Respirations: 44/min
• Pulse oximetry: 96% on room air
• The patient appears lethargic, with mild abdominal distension
• Laboratory results show:
  • Leukocytes: 6,300/mm3
  • Hemoglobin: 12 g/dL
  • Platelets: 134,000/mm3
  • Sodium: 133 mEq/L
  • Potassium: 4.0 mEq/L

Differential Diagnosis

Considering the patient's symptoms and laboratory results, necrotizing enterocolitis (NEC) is a possible diagnosis. NEC is an inflammatory bowel necrosis that affects preterm infants, with a mortality rate that is higher after perforation 2.

Imaging Modalities

Several imaging modalities can be used to evaluate NEC, including:

• Plain abdominal radiography: shows characteristic features such as pneumatosis intestinalis, portal venous gas, and pneumoperitoneum 3, 4
• Abdominal ultrasound (AUS): allows real-time assessment of vascular perfusion, bowel wall thickness, and can detect pneumatosis, altered peristalsis, and characteristics of the peritoneal fluid 3, 4, 5
• Contrast-enhanced ultrasound (CEUS): emerging modality that may provide additional insights into bowel health 5

Best Next Step in Management

Given the patient's symptoms and laboratory results, the best next step in management would be to perform an abdominal x-ray to evaluate for signs of NEC, such as pneumatosis intestinalis or portal venous gas 3, 4, 6. This is because abdominal x-ray is the current standard imaging modality for evaluating NEC, and it can provide valuable information for diagnosis and management.

Rationale

The rationale for choosing abdominal x-ray as the best next step is based on the fact that it is a widely available and non-invasive imaging modality that can provide rapid results. Additionally, abdominal x-ray is the first-line imaging modality recommended by several studies for evaluating NEC 3, 4, 6. While abdominal ultrasound is also a useful modality for evaluating NEC, it may not be as readily available or widely accepted as abdominal x-ray 6. Therefore, abdominal x-ray is the most appropriate choice for the initial evaluation of NEC in this patient.