What is the recommended dose of Pedialyte (oral rehydration solution) for a 5-month-old infant with dehydration?

Pedialyte Dosing for a 5-Month-Old Infant

For a 5-month-old infant with mild to moderate dehydration, administer 50-100 mL/kg of Pedialyte over 3-4 hours (approximately 350-700 mL total for an average 7 kg infant), then replace ongoing losses with 60-120 mL for each diarrheal stool or vomiting episode. 1, 2

Initial Rehydration Phase

Dosing by Weight and Severity

• Mild dehydration: Give 50 mL/kg over 2-4 hours 2
• Moderate dehydration: Give 100 mL/kg over 2-4 hours 2
• For an average 5-month-old weighing 7 kg, this translates to 350 mL for mild or 700 mL for moderate dehydration 1

Practical Administration Technique

• Start with 5 mL every 5 minutes for the first 30 minutes, especially if vomiting is present 1, 2
• If tolerated, increase to 10-15 mL every 10-15 minutes 1
• Use a teaspoon, syringe, or medicine dropper for precise small-volume administration 2
• The gradual approach minimizes vomiting and maximizes retention 1

Ongoing Loss Replacement

After the initial 3-4 hour rehydration period:

• Give 60-120 mL of Pedialyte for each diarrheal stool 1, 2
• Give 60-120 mL for each vomiting episode 2
• Alternative calculation: 10 mL/kg per watery stool and 2 mL/kg per vomiting episode 1, 2
• Continue replacement as long as diarrhea or vomiting persists 2

Feeding Considerations

• If breastfeeding, continue nursing throughout the illness in addition to Pedialyte 1, 2
• If formula-fed, resume regular formula after the initial 3-4 hour rehydration period 1
• Do not delay feeding until diarrhea stops 3

Severe Dehydration Warning

If the infant shows signs of severe dehydration (>10% weight loss, lethargy, sunken eyes, no tears, prolonged capillary refill >3 seconds), immediate IV rehydration with 20 mL/kg isotonic crystalloid boluses is required 1, 2, 4

• Oral rehydration is contraindicated in severe dehydration or shock 1, 2
• Once stabilized with IV fluids, transition to oral Pedialyte 2

Critical Pitfalls to Avoid

• Never use apple juice, Gatorade, sports drinks, or soft drinks - these have inappropriate electrolyte content and high osmolality that can worsen diarrhea 1, 2, 3
• Do not restrict fluids or delay feeding 1
• Do not use anti-diarrheal medications in infants 1, 2, 3
• Do not give plain water alone, as it lacks necessary electrolytes 5

Monitoring Response

Reassess hydration status after 2-4 hours by checking: 2

• Skin turgor and mucous membrane moisture
• Urine output (goal >1 mL/kg/hour)
• Mental status and activity level
• Capillary refill time (goal ≤2 seconds)

If dehydration persists or worsens despite oral rehydration, or if the infant cannot keep down Pedialyte, seek immediate medical attention for IV therapy 1, 2

Special Considerations for Young Infants

Infants under 6 months are at particularly high risk for complications from dehydration 4

• They have limited physiologic reserves and can deteriorate rapidly
• Close monitoring is essential, with reassessment every 2-4 hours 2
• Consider nasogastric administration at 15 mL/kg/hour if the infant cannot drink but is not in shock 2, 3