What is the best approach for managing vomiting in a pediatric patient?

Management of Vomiting in Pediatric Patients

For children with vomiting, initiate oral rehydration solution (ORS) using small, frequent volumes (5 mL every 1-2 minutes) administered via spoon or syringe, with gradual progression as tolerated—this approach achieves >90% success in overcoming vomiting and preventing dehydration. 1

Initial Assessment and Red Flag Identification

Immediately assess for life-threatening conditions requiring urgent intervention:

• Bilious or bloody vomiting indicates potential surgical emergency (malrotation with volvulus, intussusception, intestinal obstruction) and mandates immediate surgical consultation and NPO status with nasogastric decompression 2, 3
• Altered mental status, severe lethargy, or inconsolable irritability suggests intracranial pathology, metabolic derangement, or severe dehydration requiring immediate evaluation 2, 3
• Signs of shock (prolonged capillary refill >3 seconds, cool extremities, weak pulse) indicate severe dehydration (≥10% fluid deficit) requiring immediate IV resuscitation 1, 4

Dehydration Assessment

Classify dehydration severity using clinical examination to guide all subsequent management:

• Mild dehydration (3-5% deficit): Slightly dry mucous membranes, increased thirst, normal vital signs 1
• Moderate dehydration (6-9% deficit): Decreased skin turgor with tenting when pinched, sunken eyes, dry mucous membranes, decreased urine output, mild tachycardia 1, 4
• Severe dehydration (≥10% deficit): Markedly decreased skin turgor with prolonged tenting (>2 seconds), severe lethargy or altered consciousness, cool and poorly perfused extremities, rapid deep breathing indicating acidosis 1, 4

Capillary refill time is the most reliable predictor of dehydration in children and should be prioritized over less reliable signs like sunken fontanelle or absent tears 4

Rehydration Protocol Based on Severity

For Mild Dehydration (3-5% deficit):

• Administer 50 mL/kg of ORS over 2-4 hours 1, 5
• Use small volumes (5-10 mL) every 1-2 minutes initially to overcome vomiting 1, 5
• Critical technique: Administer via spoon or syringe with close supervision—never allow ad libitum drinking as this worsens vomiting 5

For Moderate Dehydration (6-9% deficit):

• Administer 100 mL/kg of ORS over 2-4 hours using the same small-volume technique 1, 5
• Consider nasogastric administration if oral intake is not tolerated 4

For Severe Dehydration (≥10% deficit):

• Immediate IV resuscitation with 20 mL/kg boluses of Ringer's lactate or normal saline until pulse, perfusion, and mental status normalize 5, 4
• Once circulation is restored, transition to ORS for remaining deficit replacement 4

Ongoing Loss Replacement

After initial rehydration:

• Replace 10 mL/kg of ORS for each watery stool 1, 5
• Replace 2 mL/kg of ORS for each vomiting episode 1, 5
• Continue maintenance fluids until vomiting and diarrhea resolve 5

Nutritional Management During Illness

Do not withhold feeding—there is no justification for "bowel rest":

• Breastfed infants: Continue nursing on demand without any interruption throughout the entire episode 1, 5
• Bottle-fed infants: Resume full-strength formula immediately upon rehydration (lactose-free or lactose-reduced formula acceptable) 1, 5
• Older children: Resume age-appropriate diet immediately upon rehydration including starches, cereals, yogurt, fruits, and vegetables; avoid foods high in simple sugars and fats 1, 5

Antiemetic Medication: When and What to Use

Ondansetron is the only antiemetic with sufficient evidence for use in pediatric vomiting:

• Indication: Consider ondansetron when vomiting prevents adequate oral intake and hinders oral rehydration therapy 1, 5, 6, 7
• Dosing: 0.15 mg/kg IV/IM or 0.2 mg/kg oral (maximum 4 mg per dose) 2
• Age restriction: FDA-approved for children ≥4 years of age 8
• Evidence: Single oral dose reduces recurrent vomiting, need for IV fluids, and hospital admissions without significant adverse events 6, 7

Contraindicated medications:

• Metoclopramide and other antimotility agents are absolutely contraindicated in all children <18 years due to risk of extrapyramidal reactions, respiratory depression, and serious cardiac adverse reactions 5, 4, 9
• Loperamide has been associated with severe abdominal distention and death in children 10

Hospitalization Criteria

Admit patients with:

• Severe dehydration (≥10% deficit) or signs of shock 1
• Intractable vomiting despite ondansetron and small-volume ORS trial 1
• Altered mental status or severe lethargy 1
• High stool output (>10 mL/kg/hour) 5
• Bilious vomiting requiring surgical evaluation 2

Antibiotic Considerations

Antibiotics are NOT routinely indicated for acute gastroenteritis with vomiting:

• Consider antibiotics only when dysentery (bloody diarrhea) is present, high fever accompanies diarrhea, or watery diarrhea persists >5 days 1, 5
• Stool cultures should guide specific antimicrobial therapy when indicated 10

Critical Pitfalls to Avoid

• Never allow a thirsty child to drink large volumes of ORS ad libitum—this common mistake worsens vomiting; always use small, frequent volumes 5
• Do not use cola drinks or soft drinks for rehydration—they contain inadequate sodium and excessive osmolality that worsens diarrhea 4
• Do not rely solely on sunken fontanelle or absent tears for dehydration assessment—these are less reliable than capillary refill time and skin turgor 4
• Do not prescribe antimotility agents (loperamide, metoclopramide) in children—they are contraindicated and potentially dangerous 10, 5, 4

Parent Education and Home Management

Instruct caregivers to return immediately if:

• Decreased urine output, lethargy, or increased irritability develops 1, 5
• Intractable vomiting continues despite small-volume ORS 1
• Bloody diarrhea or bilious vomiting occurs 5
• High fever or persistent diarrhea >5 days develops 1

Provide a 24-hour supply of ORS at discharge and emphasize that ORS should be a household staple like acetaminophen 1