What is the best approach to manage nausea in a child?

Management of Nausea in Children

The cornerstone of managing nausea in children is oral rehydration with small, frequent volumes (5 mL every 1-2 minutes) of oral rehydration solution (ORS), with ondansetron reserved for children ≥4 years with persistent vomiting that impedes oral intake. 1, 2

Immediate Red Flag Assessment

Before initiating treatment, rapidly assess for conditions requiring emergency intervention:

• Bilious (green) vomiting indicates possible intestinal obstruction or malrotation with volvulus and requires immediate surgical consultation 2, 3
• Projectile vomiting that persists may indicate pyloric stenosis or other obstructive pathology requiring urgent evaluation 2, 3
• Abdominal distension or tenderness necessitates emergency care 3
• Signs of severe dehydration (severe lethargy, prolonged skin tenting, cool extremities, minimal urine output) require immediate intravenous rehydration 3

Hydration Status Determination

Physical examination is the most reliable method to assess dehydration severity 4:

• Mild dehydration: Slightly dry mucous membranes, normal mental status, normal urine output 3
• Moderate dehydration: Sunken eyes, decreased skin turgor, reduced urine output, increased thirst 3
• Severe dehydration: Severe lethargy, prolonged skin tenting, cool extremities, minimal urine output, signs of shock 3

Rehydration Protocol

For Mild to Moderate Dehydration

The critical technique is administering small volumes frequently—not allowing the child to drink large amounts at once, which triggers more vomiting 1, 3:

• Start with 5 mL of ORS every 1-2 minutes using a spoon or syringe under close supervision 1, 2
• Gradually increase volume as tolerated 2
• Target 50-100 mL/kg of ORS over 2-4 hours for moderate dehydration 3
• Replace each vomiting episode with an additional 2 mL/kg of ORS 3
• Over 90% of children with vomiting can be successfully rehydrated orally when this technique is properly applied 1, 2

For Severe Dehydration

• Initiate immediate intravenous rehydration with 20 mL/kg boluses of Ringer's lactate or normal saline until vital signs normalize 3
• Transition to oral rehydration as soon as the patient is stable 5

Ondansetron Use

Ondansetron should only be considered after attempting oral rehydration, not as first-line therapy 1, 3:

• Indicated for children ≥4 years with persistent vomiting that impedes oral rehydration 1, 2, 6
• Dose: 0.2 mg/kg orally (maximum 4 mg) or 0.15 mg/kg parenterally 2, 6
• For children 4-11 years: 4 mg administered 30 minutes before chemotherapy (if applicable), with subsequent doses 6
• For children 12-17 years: 8 mg with subsequent dosing 6
• Do NOT use routinely in children <4 years—no recommendation can be made for this age group 1
• Ondansetron may increase stool volume as a side effect 1
• Monitor for QT prolongation in patients with electrolyte abnormalities, congestive heart failure, or bradyarrhythmias 6

Nutritional Management During Illness

Continue normal feeding—do not withhold food for 24 hours 1:

• Breastfed infants: Continue nursing on demand throughout the illness 1, 2
• Formula-fed infants: Continue full-strength formula if tolerated; only consider lactose-free formula if true intolerance is suspected (worsening diarrhea upon reintroduction) 1, 2
• Older children on solid foods: Continue usual diet with starches, cereals, yogurt, fruits, and vegetables 1, 2
• Avoid foods high in simple sugars and fats 1, 2
• The BRAT diet (bananas, rice, applesauce, toast) has limited supporting data and is not necessary 1

Critical Medications to AVOID

Never administer antimotility drugs (loperamide) to children <18 years with nausea, vomiting, or diarrhea 1, 3:

• Loperamide can cause serious complications including ileus, abdominal distension, lethargy, and toxic megacolon 1
• Deaths have been reported in 0.54% of children given loperamide, all occurring in children <3 years old 1

Common Pitfalls to Avoid

• Do not give large volumes of ORS at once—this is the most common mistake and will trigger more vomiting; small, frequent volumes are essential 1, 3
• Do not use apple juice, Gatorade, or soft drinks for rehydration—these have inappropriate osmolarity and electrolyte composition 3
• Do not routinely use antiemetics before attempting proper oral rehydration—most children respond to correct ORS administration alone 1, 3
• Do not withhold solid food for 24 hours—early refeeding improves outcomes 1

When to Return for Emergency Care

Instruct parents to return immediately if 1, 3:

• Vomiting becomes bilious (green) or bloody 3
• Child becomes increasingly lethargic or difficult to arouse 3
• No urine output for >8 hours 3
• Signs of severe dehydration develop despite oral rehydration attempts 3
• Persistent symptoms beyond 5 days, especially with high fever 3

Antibiotics

Antibiotics are generally NOT indicated unless there is evidence of bacterial infection 1:

• Consider only when dysentery or high fever is present, watery diarrhea lasts >5 days, or stool cultures indicate a treatable pathogen 1