Recommended Oral Rehydration Solutions for Treating Dehydration
The World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) recommend oral rehydration solutions (ORS) containing sodium (65-70 mEq/L), glucose (75-90 mmol/L), and potassium (20 mEq/L) as the optimal composition for treating dehydration. 1
Optimal ORS Composition
The ideal oral rehydration solution should contain:
- Sodium: 65-90 mEq/L
- Glucose: 75-90 mmol/L (not exceeding 2.5%)
- Potassium: 20 mEq/L
- Chloride: 65-80 mEq/L
- Citrate: 10 mEq/L
Available Commercial Products
In the United States, several commercial ORS products are available with varying compositions 2:
- For Rehydration (75-90 mEq/L sodium): These solutions are recommended by the American Academy of Pediatrics for actual rehydration therapy
- For Maintenance (40-60 mEq/L sodium): Products like Pedialyte (45 mEq/L sodium) and Ricelyte (50 mEq/L sodium) are widely used for maintenance of hydration and prevention of dehydration
Rehydration Protocol
For effective rehydration:
- Mild dehydration (3-5%): 50 mL/kg over 2-4 hours
- Moderate dehydration (6-9%): 100 mL/kg over 2-4 hours
- After initial rehydration: 10 mL/kg after each loose stool and 2 mL/kg after each episode of vomiting 1
Inappropriate Alternatives
The following should NOT be used for rehydration:
- Sports drinks
- Fruit juices
- Soft drinks
- Chicken broth
These beverages have inappropriate sodium and glucose concentrations and may worsen dehydration 3.
Special Considerations
For High-Output Diarrhea
When the rate of purging is very high (>10 mL/kg/hour), solutions with 75-90 mEq/L sodium are specifically recommended for rehydration 2.
For Borderline Dehydration
For patients with borderline dehydration or sodium depletion, isotonic high-sodium oral rehydration solutions are recommended to replace sodium losses 2.
For Patients with Short Bowel Syndrome
Patients with short bowel syndrome should limit intake of both hypotonic (water, tea, coffee) and hypertonic (fruit juices, colas) solutions as these may stimulate fluid secretion and worsen losses 2.
Practical Administration Tips
- Use salt liberally with meals for patients at risk of sodium depletion
- Restrict oral fluids in relation to meals for patients with short bowel syndrome
- For children: 50-100 mL after each stool for children <2 years; 100-200 mL for older children
- For adults: As much as desired according to thirst 1
Common Pitfalls
- Using inappropriate fluids: Sports drinks, juices, and sodas have improper electrolyte compositions and can worsen dehydration
- Improper mixing of ORS packets: When using packets, precise measurement of water is critical to avoid solutions that are too concentrated or too dilute 2
- Neglecting maintenance therapy: After initial rehydration, continued replacement of ongoing losses is essential
- Failing to continue feeding: The American Academy of Pediatrics recommends continuing feeding during rehydration 1
While the CDC guidelines from 1992 2 and more recent evidence 1 both support the use of ORS with sodium concentrations of 65-90 mEq/L, studies have shown that both 90 mEq/L and 75 mEq/L sodium solutions are safe and effective for treating even hypernatremic dehydration 4, 5.