Treatment of Diarrhea in an 8-Month-Old Infant
Oral rehydration solution (ORS) is the cornerstone of treatment for an 8-month-old with diarrhea, combined with continued breastfeeding or formula feeding and zinc supplementation. 1, 2
Immediate Assessment
Rapidly assess hydration status by examining:
- Skin turgor, mucous membranes, mental status, pulse, and capillary refill time 1
- Weight loss (most reliable clinical indicator) 1
Classify dehydration severity:
- Mild (3-5% fluid deficit): Administer 50 mL/kg of ORS over 2-4 hours 1, 2
- Moderate (6-9% fluid deficit): Administer 100 mL/kg of ORS over 2-4 hours 1, 2
- Severe (≥10% fluid deficit, shock): Immediately initiate IV rehydration with 20 mL/kg boluses of Ringer's lactate or normal saline until pulse, perfusion, and mental status normalize, then transition to ORS 1, 3
Managing Concurrent Vomiting
If the infant is vomiting, administer small, frequent volumes of ORS (5 mL every 1-2 minutes) using a spoon or syringe, gradually increasing the amount. 1 A common pitfall is allowing a thirsty infant to drink large volumes of ORS ad libitum, which worsens vomiting. 3
Replacing Ongoing Losses
After initial rehydration, replace ongoing losses with:
- 10 mL/kg of ORS for each liquid stool 1, 2
- 2 mL/kg of ORS for each vomiting episode 1, 2
- Continue until diarrhea and vomiting resolve 4, 3
Nutritional Management
Continue breastfeeding on demand throughout the entire diarrheal episode without interruption. 1, 3 This is a strong recommendation from the World Health Organization and should never be stopped. 4
If formula-fed, resume full-strength formula immediately upon rehydration. 1 Consider lactose-free or lactose-reduced formula as lactose intolerance may temporarily develop. 1
Resume age-appropriate solid foods during or immediately after rehydration is completed. 4, 2 Recommended foods include starches, cereals, yogurt, fruits, and vegetables; avoid foods high in simple sugars and fats. 3
Zinc Supplementation
Administer oral zinc supplementation, as it reduces the duration of diarrhea in children aged 6 months to 5 years. 4, 1, 2 This is particularly important for infants with signs of malnutrition or those in areas with high zinc deficiency prevalence. 4, 3
Medications to AVOID
Do not use antimotility drugs (loperamide) in this 8-month-old infant—they are absolutely contraindicated in all children under 18 years of age. 4, 2, 3 This is a strong recommendation with moderate-quality evidence. 4
Do not use antiemetics (ondansetron) in this age group, as they are only recommended for children >4 years of age. 4, 2, 3
Do not routinely use antibiotics unless bloody diarrhea (dysentery), high fever, or watery diarrhea persisting >5 days is present. 1, 3
Adjunctive Therapy
Probiotic preparations may be offered to reduce symptom severity and duration in immunocompetent infants with infectious diarrhea. 4, 2, 3 However, this is a weak recommendation with moderate-quality evidence. 4
Monitoring and Red Flags
Reassess hydration status after 2-4 hours of rehydration. 1, 3 If the infant remains dehydrated, reassess the fluid deficit and restart the rehydration protocol. 1
Seek immediate medical attention if:
- Bloody diarrhea (dysentery) develops 3
- Severe dehydration with shock persists 3
- Intractable vomiting prevents successful oral rehydration 3
- High stool output (>10 mL/kg/hour) occurs 3
- Decreased urine output, lethargy, or irritability develops 3
Prevention
Hand hygiene should be performed after diaper changes, before and after food preparation, and before eating to prevent transmission. 4, 3