What is the initial management of a 2-month-old infant presenting to the emergency department (ED) with vomiting?

Emergency Department Management of a 2-Month-Old Infant with Vomiting

The initial management of a 2-month-old infant presenting to the emergency department with vomiting should prioritize assessment for red flag signs, evaluation of hydration status, and appropriate diagnostic workup based on the nature of vomiting. 1

Initial Assessment

• Perform rapid assessment of airway, breathing, and circulation to identify any immediate life-threatening conditions 2
• Carefully evaluate the nature of vomiting - bilious vomiting is a surgical emergency until proven otherwise and requires immediate attention 1, 3
• Assess for red flag signs including:
  • Bilious or bloody vomiting 1, 2
  • Altered mental status or neurological signs 1
  • Abdominal distention or signs of obstruction 1
  • Excessive irritability or inconsolable crying 2
  • Severe dehydration 2

History Elements to Obtain

• Timing and frequency of vomiting episodes 1
• Associated symptoms (fever, diarrhea, irritability, lethargy) 1
• Feeding patterns and recent changes 1
• Stool characteristics (bloody, "currant jelly" appearance) 1
• Recent illness exposure or sick contacts 2

Physical Examination

• Complete assessment of hydration status (skin turgor, mucous membranes, fontanelle, urine output) 1, 2
• Abdominal examination for distention, tenderness, and palpable masses 1
• Neurological assessment including fontanelle examination and mental status 1
• Vital signs including temperature, heart rate, respiratory rate, and blood pressure 2, 4

Diagnostic Workup

• For non-bilious vomiting without red flags:

  • Laboratory tests may not be necessary if the infant appears well-hydrated and has no concerning features 1
  • Consider ultrasound of the abdomen if pyloric stenosis is suspected (especially in infants 2 weeks to 3 months of age) 5, 1

• For infants with concerning features:

  • Obtain serum electrolytes, blood gases, renal and liver function tests if dehydration or red flag signs are present 2
  • Abdominal radiography is appropriate for suspected obstruction 5, 1
  • For bilious vomiting, upper GI series is the appropriate next step after initial assessment 5, 1

Management Based on Presentation

For Non-Bilious Vomiting Without Red Flags:

• Begin oral rehydration therapy with small, frequent volumes (e.g., 5 mL every minute) 5, 1
• For breastfed infants, continue breastfeeding 5
• For formula-fed infants, consider full-strength, lactose-containing formulas under supervision 5
• Monitor response to rehydration and feeding 5

For Bilious Vomiting or Red Flags Present:

• Immediate surgical consultation 1, 3
• NPO (nothing by mouth) status 2
• Consider nasogastric tube for stomach decompression 2
• Obtain abdominal radiography followed by upper GI series 5, 1
• Administer IV fluids for rehydration if needed 2

For Persistent Vomiting Affecting Oral Intake:

• Consider ondansetron (0.15 mg/kg IV or 0.2 mg/kg oral; maximum 4 mg) if the infant is unable to tolerate oral rehydration due to persistent vomiting 2

Common Pitfalls to Avoid

• Delaying evaluation of bilious vomiting - this is a surgical emergency until proven otherwise 1, 3
• Failing to recognize signs of increased intracranial pressure, such as bulging fontanelle 1
• Overlooking hypertrophic pyloric stenosis in infants 2 weeks to 3 months of age 5, 1
• Administering antiemetics before determining the underlying cause, which may mask important diagnostic clues 4

Follow-up and Disposition

• For infants with no red flags who respond well to rehydration, discharge with clear instructions to parents about warning signs that should prompt return 5
• For infants with concerning features or poor response to initial management, admission for further evaluation and treatment 4
• Parents should be instructed to return if the infant becomes irritable or lethargic, has decreased urine output, develops intractable vomiting, or has persistent symptoms 5