Treatment of Mild Dehydration
For mild dehydration, reduced osmolarity oral rehydration solution (ORS) is the first-line treatment, administered at a volume of 50 mL/kg over 2-4 hours. 1
Assessment of Dehydration
Mild dehydration (3-5% fluid deficit) presents with:
- Increased thirst
- Slightly dry mucous membranes
- Normal mental status
- Normal skin turgor or minimal changes
Treatment Algorithm
Step 1: Rehydration Phase
- For mild dehydration (3-5% fluid deficit):
- Administer ORS containing 50-90 mEq/L of sodium
- Volume: 50 mL/kg over 2-4 hours 1
- Start with small volumes (e.g., one teaspoon) and gradually increase as tolerated
- Commercially available ORS options include Pedialyte, CeraLyte, and Enfalac Lytren 1
- Avoid inappropriate fluids such as apple juice, Gatorade, and commercial soft drinks 1
Step 2: Reassess Hydration Status
- After 2-4 hours, reassess the patient's hydration status
- If rehydrated: Progress to maintenance phase
- If still dehydrated: Re-estimate fluid deficit and restart rehydration therapy 1
Step 3: Maintenance Phase
- Once rehydrated, provide maintenance fluids
- Replace ongoing fluid losses from continued diarrhea or vomiting with additional ORS 1, 2
- Resume age-appropriate diet during or immediately after rehydration 1
- For infants: Continue breastfeeding throughout the illness 1
Special Considerations
Oral Rehydration Technique
- For optimal success with ORS, patients should consume approximately 25 mL/kg during initial rehydration 3
- Patients who tolerate less than 15 mL/kg may be at higher risk for treatment failure
Effectiveness of Oral vs. Intravenous Rehydration
- ORS is as effective as IV fluids for rehydration of moderately dehydrated children 4
- ORS therapy can be initiated more quickly than IV therapy (19.9 vs. 41.2 minutes) 4
- ORS is associated with lower hospitalization rates compared to IV therapy 4
Contraindications to Oral Rehydration
- Severe dehydration (≥10% fluid deficit)
- Shock
- Altered mental status
- Ileus
- Inability to tolerate oral intake 1, 2
Monitoring
- Monitor for signs of worsening dehydration
- Assess urine output and weight gain as indicators of successful rehydration
- Watch for severe emesis (≥5 mL/kg) which may indicate need for alternative therapy 4
Adjunctive Therapies
- Antiemetics (e.g., ondansetron) may be considered for children >4 years with significant vomiting to facilitate ORS tolerance 1
- Antimotility agents should be avoided in children <18 years 1
- Probiotics may reduce symptom severity and duration in immunocompetent individuals 1
ORS therapy has been credited with saving millions of lives in the management of dehydration across all age groups and is recommended by the World Health Organization as first-line therapy for mild to moderate dehydration 1. The approach is both cost-effective and avoids complications associated with intravenous therapy such as phlebitis 1.
Human medical studies, meta-analyses, and clinical practice guidelines consistently support the effectiveness and safety of oral rehydration therapy for mild dehydration, making it the preferred treatment approach in most clinical scenarios.