What is the management approach for pediatric patients presenting with vomiting?

Management of Vomiting in Pediatric Patients

For children with vomiting, oral rehydration therapy (ORS) using small, frequent volumes (5 mL every minute) is the first-line treatment, with simultaneous correction of dehydration often reducing vomiting frequency. 1, 2

Initial Assessment

Immediately evaluate for life-threatening conditions and assess hydration status by examining:

• Red flag signs requiring urgent intervention: bilious or bloody vomiting, altered mental status, severe dehydration, toxic/septic appearance, inconsolable crying, or bent-over posture 3
• Skin turgor, mucous membrane moisture, mental status, pulse, capillary refill, and urine output 2, 4
• Degree of dehydration: mild (3-5% fluid deficit), moderate (6-9% fluid deficit), or severe (≥10% fluid deficit) 2, 4

If bilious vomiting is present, immediately stop oral intake and place a nasogastric tube for gastric decompression while evaluating for surgical causes such as malrotation with volvulus or intestinal obstruction. 3

Oral Rehydration Technique for Vomiting Children

The key to successful oral rehydration in vomiting children is administering small volumes frequently rather than allowing ad libitum drinking: 1, 4

• Start with 5 mL of ORS every 1-2 minutes using a spoon or syringe under close supervision 1
• Gradually increase the amount as tolerated 1
• Over 90% of vomiting children can be successfully rehydrated orally using this technique 4
• For intractable vomiting despite small-volume technique, consider continuous nasogastric ORS infusion 1, 4

Common pitfall: Allowing a thirsty child to drink large volumes rapidly from a cup or bottle will perpetuate vomiting and lead to oral rehydration failure. 1

Rehydration Volumes

Based on dehydration severity:

• Mild dehydration (3-5%): 50 mL/kg ORS over 2-4 hours 2, 4
• Moderate dehydration (6-9%): 100 mL/kg ORS over 2-4 hours 2, 4
• Ongoing losses: Replace each vomiting episode with 2 mL/kg ORS 2, 4

Antiemetic Use

Ondansetron may be considered for children over 4 years old when vomiting is severe enough to prevent oral rehydration: 2

• Dose: 0.15 mg/kg IV (maximum 4 mg) or 0.2 mg/kg oral (maximum 4 mg) 5, 3
• Indications: Persistent vomiting preventing oral intake, post-operative vomiting, chemotherapy-induced vomiting, cyclic vomiting syndrome 3
• The FDA label notes safety and effectiveness are established in pediatric patients 4 years and older for chemotherapy-induced nausea/vomiting 5

Important caveat: While ondansetron can facilitate oral rehydration, the primary strategy remains small-volume frequent ORS administration, as this succeeds in over 90% of cases without medication. 1, 4

Dietary Management

• Breastfed infants: Continue nursing on demand throughout the illness 2, 4
• Bottle-fed infants: Resume full-strength formula immediately after rehydration 2, 4
• Older children: Resume normal age-appropriate diet immediately after rehydration or during the rehydration process 2, 6
• Do not withhold food once rehydration is achieved 2

Medications to Avoid

Antimotility drugs (loperamide) should never be given to children under 18 years with acute diarrhea due to risks of toxic megacolon and serious cardiac adverse events. 2, 6

Indications for IV Rehydration

Children requiring IV fluids rather than oral rehydration include those with: 1, 3

• Severe dehydration or shock
• Altered mental status preventing safe oral intake
• Intestinal ileus (absent bowel sounds)
• True intractable vomiting despite proper small-volume ORS technique
• Large urinary ketones combined with altered mental status (these predict IV rehydration need) 7

A serum bicarbonate ≤13 mEq/L predicts failure of oral rehydration after rapid IV correction and typically requires hospital admission for continued IV therapy. 8

When to Seek Immediate Medical Attention

Instruct parents to return or call if the child develops: 1, 2

• Inability to tolerate any oral fluids
• Decreased urine output
• Increased lethargy or irritability
• Persistent or worsening vomiting
• Bloody vomit or stool
• High fever

Children with ≥10 vomiting episodes in the 24 hours before presentation or persistent tachycardia at discharge are at higher risk for return visits and warrant closer follow-up. 7