What is the recommended IV fluid choice for a pediatric patient with vomiting, considering their age, weight, and medical history?

IV Fluid Choice for Pediatric Patients with Vomiting

For pediatric patients with vomiting and dehydration, oral rehydration solution (ORS) is first-line therapy for mild-to-moderate dehydration, while isotonic crystalloids (normal saline or lactated Ringer's) are indicated for severe dehydration with shock. 1

Initial Assessment

Assess dehydration severity using clinical examination:

• Mild dehydration (3-5% fluid deficit): Increased thirst, slightly dry mucous membranes 1
• Moderate dehydration (6-9% fluid deficit): Loss of skin turgor, dry mucous membranes, decreased urine output 1
• Severe dehydration (≥10% fluid deficit): Altered mental status, prolonged capillary refill (>2 seconds), cool extremities, poor perfusion, rapid deep breathing 1

Capillary refill time is the most reliable predictor of dehydration in children, more so than sunken fontanelle or absent tears. 1, 2

Obtain accurate body weight to calculate fluid deficit and guide therapy. 1

Treatment Algorithm by Dehydration Severity

Mild Dehydration (3-5% deficit)

Administer 50 mL/kg of ORS over 2-4 hours. 1

• Use small, frequent volumes initially (5 mL every 1-2 minutes) via teaspoon, syringe, or medicine dropper 1
• Gradually increase volume as tolerated 1
• Common pitfall: Allowing thirsty children to drink large volumes ad libitum worsens vomiting 1, 3

Moderate Dehydration (6-9% deficit)

Administer 100 mL/kg of ORS over 2-4 hours using the same small-volume technique. 1

If oral intake fails despite proper technique, consider nasogastric administration of ORS. 1

Severe Dehydration (≥10% deficit, shock, or near-shock)

This is a medical emergency requiring immediate IV resuscitation. 1

Administer 20 mL/kg boluses of isotonic crystalloid (normal saline or lactated Ringer's) IV until pulse, perfusion, and mental status normalize. 1, 4

• Special consideration for malnourished infants: Use smaller-volume, frequent boluses of 10 mL/kg due to reduced cardiac capacity 1, 4
• May require two IV lines or alternate access sites (venous cutdown, femoral vein, intraosseous) 1
• Once consciousness returns to normal, transition to ORS for remaining deficit 1, 4

Reassess after 2-4 hours: If rehydrated, progress to maintenance phase; if still dehydrated, reestimate deficit and continue therapy. 1

Ongoing Loss Replacement

Replace continuing losses throughout treatment:

• 10 mL/kg of ORS for each watery/loose stool 1, 2, 4, 3
• 2 mL/kg of ORS for each vomiting episode 1, 2, 4

Continue replacement until diarrhea and vomiting resolve. 1

Maintenance IV Fluids (When Oral Route Unavailable)

If unable to tolerate oral intake after initial resuscitation, use 5% dextrose in 0.25 normal saline with 20 mEq/L potassium chloride IV for maintenance. 1

For general maintenance IV therapy in hospitalized children, isotonic fluids are safer than hypotonic fluids to prevent iatrogenic hyponatremia. 1, 5, 6

• Consider restricting maintenance fluid volume to 65-80% of Holliday-Segar formula in children at risk of increased ADH secretion (common with vomiting/nausea) 1
• Reassess fluid balance and electrolytes at least daily 1

Nutritional Management

Resume age-appropriate diet immediately upon rehydration—do not delay feeding. 1, 2

• Breastfed infants: Continue nursing on demand throughout illness without interruption 1, 2, 3
• Bottle-fed infants: Resume full-strength formula immediately upon rehydration 1, 2, 3
• Older children: Starches, cereals, yogurt, fruits, vegetables; avoid foods high in simple sugars and fats 1, 2

Critical Pitfalls to Avoid

Never use hypotonic solutions for initial resuscitation in severe dehydration—they worsen hyponatremia in states of elevated ADH. 6

Do not use popular beverages (apple juice, Gatorade, soft drinks) for rehydration—they contain inadequate sodium and excessive osmolality. 1, 2

Antimotility drugs (loperamide) are absolutely contraindicated in all children <18 years due to risks of respiratory depression and serious cardiac adverse reactions. 2, 3

Do not routinely order laboratory tests for mild-moderate dehydration unless specific clinical indications exist. 2

When to Hospitalize

• Severe dehydration (≥10% deficit) or signs of shock 4
• Failure of oral rehydration therapy despite proper technique 1
• Altered mental status or ileus 1
• Serum bicarbonate ≤13 mEq/L predicts higher likelihood of requiring hospitalization 7

Monitoring Parameters

• Pulse quality and rate, capillary refill time, mental status, perfusion 4
• Urine output 3
• Hydration status reassessment after 2-4 hours 1, 2, 3
• Electrolytes (especially sodium) if receiving IV fluids 1