What is the management approach for a pediatric patient presenting with vomiting and fever?

Management of Pediatric Vomiting with Fever

Assess hydration status immediately and initiate oral rehydration therapy with small, frequent volumes of ORS (5 mL every minute initially), as this is the cornerstone of management for most children with vomiting and fever, regardless of the underlying cause. 1

Initial Assessment and Risk Stratification

Determine the severity of dehydration first, as this drives all subsequent management decisions:

• Mild dehydration (3-5% fluid deficit): Increased thirst, slightly dry mucous membranes 2, 3
• Moderate dehydration (6-9% fluid deficit): Loss of skin turgor, skin tenting when pinched, dry mucous membranes 2, 3
• Severe dehydration (≥10% fluid deficit): Severe lethargy, prolonged skin tenting, cool extremities, decreased capillary refill, rapid deep breathing, signs of shock 2, 3

Identify red flags requiring urgent evaluation:

• Bilious (green) vomiting suggests intestinal obstruction and requires emergency surgical evaluation 1
• Projectile vomiting may indicate pyloric stenosis or increased intracranial pressure 1
• Age <3 months with fever requires careful evaluation for serious bacterial infection 3
• Altered mental status, severe lethargy, or signs of sepsis 3

Consider the differential diagnosis based on age and presentation:

• Neonates and young infants: May present with non-specific signs of sepsis (pallor, floppiness, poor feeding, apnea), with fever potentially being the only feature 2
• Infants and toddlers (<2 years): Gastroenteritis is most common, but also consider febrile seizures, otitis media, and urinary tract infection 2
• Older children: Consider influenza (especially with cough, headache, pharyngitis triad), bacterial gastroenteritis if diarrhea is bloody or persistent, and appendicitis if abdominal pain is prominent 2, 3

Rehydration Strategy Based on Severity

Mild Dehydration (No Shock, Minimal Dehydration)

Start oral rehydration immediately with 50 mL/kg ORS over 2-4 hours 2:

• Begin with very small volumes (5 mL or one teaspoon) every minute using a spoon, syringe, or medicine dropper 1
• Gradually increase volume as tolerated 2, 1
• Replace each vomiting episode with an additional 2 mL/kg of ORS 2
• Reassess hydration status after 2-4 hours 2

Consider ondansetron to facilitate oral rehydration if vomiting is persistent and the child is >4 years old:

• Dose: 0.2 mg/kg orally (maximum 4 mg) 1
• This improves tolerance of oral fluids and reduces need for IV therapy 4, 5
• Caution: Some emergency pediatricians use ondansetron in younger children, but evidence is strongest for children >4 years 1

Moderate Dehydration (6-9% Deficit)

Administer 100 mL/kg ORS over 2-4 hours using the same gradual approach 2:

• Continue replacing ongoing losses (10 mL/kg for each watery stool, 2 mL/kg for each vomiting episode) 2, 3
• If the child cannot tolerate oral fluids despite ondansetron, consider nasogastric tube rehydration before resorting to IV therapy 6
• Alternative approach: Rapid IV rehydration (20-30 mL/kg isotonic crystalloid over 1-2 hours) followed by oral challenge may be effective, especially if serum bicarbonate >13 mEq/L 7

Severe Dehydration (≥10% Deficit, Shock)

This is a medical emergency requiring immediate IV access and aggressive fluid resuscitation 2:

• Administer 20 mL/kg boluses of Ringer's lactate or normal saline until pulse, perfusion, and mental status normalize 2, 3
• May require two IV lines or alternate access (venous cutdown, femoral vein, intraosseous) 2
• Once mental status improves, transition to oral rehydration for remaining deficit 2

Nutritional Management During Illness

Continue feeding as soon as rehydration is achieved—do not withhold nutrition 2, 1:

• Breastfed infants: Continue nursing on demand throughout the illness 2, 1, 3
• Formula-fed infants: Resume full-strength formula immediately after rehydration; use lactose-free or lactose-reduced formula only if lactose intolerance is clinically evident (worsening diarrhea with formula reintroduction) 2, 1
• Older children on solid foods: Continue usual diet with emphasis on starches, cereals, yogurt, fruits, and vegetables 2, 1
• Avoid: Foods high in simple sugars and fats 2, 1

When to Consider Antibiotics

Antibiotics are NOT routinely indicated for vomiting with fever unless specific criteria are met 3:

• High fever (>39°C) with bloody diarrhea or mucus in stool suggests bacterial enteritis 3
• Persistent symptoms >5 days with worsening clinical status 3
• Marked leukocytosis with signs of systemic bacterial infection 3
• First-line antibiotic: Azithromycin for suspected bacterial gastroenteritis 3
• Critical caveat: Do NOT give antibiotics if Shiga toxin-producing E. coli (STEC) is suspected, as this can precipitate hemolytic uremic syndrome 3

Disposition Decisions

Admit to hospital if:

• Severe dehydration or failed oral rehydration therapy despite ondansetron 3
• Age <3 months with fever and suspected bacterial infection 3
• Altered mental status, signs of sepsis, or hemodynamic instability 3
• Bilious vomiting or signs of surgical abdomen 1
• Caregiver unable to provide adequate monitoring at home 3

Discharge home with close follow-up if:

• Successfully rehydrated and tolerating oral fluids 3
• Reliable caregiver with clear return precautions 3
• No red flag features requiring admission 1, 3

Provide explicit return precautions: Return immediately for decreased urine output, increasing lethargy, intractable vomiting, bloody stools, or worsening clinical status 1

Common Pitfalls to Avoid

• Do not wait for laboratory confirmation before starting rehydration—clinical assessment drives initial management 2, 3
• Do not use antimotility agents (loperamide) in children <18 years, as they increase risk of complications 1
• Do not routinely use antiemetics without attempting oral rehydration first—ondansetron is an adjunct, not a replacement for proper hydration 1
• Do not assume all vomiting with fever is viral gastroenteritis—maintain vigilance for serious bacterial infections, especially in young infants 2, 3
• Waiting room oral rehydration can be highly effective and reduces need for IV therapy and admission rates significantly (from 56% to 28% in one study) 8