What is the initial treatment for dehydration in pediatric patients?

Treatment of Dehydration in Pediatric Patients

Oral rehydration solution (ORS) is the initial treatment for all children with mild to moderate dehydration, while severe dehydration requires immediate intravenous fluid resuscitation followed by transition to ORS. 1, 2

Initial Assessment and Stratification

Determine the degree of dehydration through physical examination to guide treatment intensity:

• 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 1
• Severe dehydration (≥10% fluid deficit): Severe lethargy or altered consciousness, prolonged skin tenting 1

The most reliable clinical indicators are prolonged capillary refill time, abnormal skin turgor, and abnormal respiratory pattern—these are more predictive than sunken fontanelle or absent tears 1, 3.

Treatment Algorithm by Severity

Mild Dehydration (3-5% Fluid Deficit)

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

• Use ORS containing 50-90 mEq/L of sodium 1
• The World Health Organization recommends reduced osmolarity ORS (total osmolarity <250 mmol/L) 2
• Replace ongoing losses with 10 mL/kg ORS for each watery stool and 2 mL/kg for each vomiting episode 2, 4

Moderate Dehydration (6-9% Fluid Deficit)

Administer 100 mL/kg of ORS over 2-4 hours 1, 2, 4

• Use the same ORS formulation as for mild dehydration 1
• Continue replacing ongoing losses as above 2
• Reassess hydration status after 2-4 hours; if still dehydrated, reassess fluid deficit and restart rehydration 4

Severe Dehydration (≥10% Fluid Deficit)

This is a medical emergency requiring immediate IV rehydration 1

• Administer 60-100 mL/kg of Ringer's lactate solution or 0.9% normal saline as boluses in the first 2-4 hours to restore circulation 1, 5
• For oliguric patients with severe acidosis, give physiological dose of bicarbonate to correct blood pH to 7.25 5
• Once circulation is restored, transition to ORS given in small quantities over 6-8 hours 5
• If ORS cannot be tolerated, continue IV rehydration for remainder of deficit and maintenance 5

Special Considerations for ORS Administration

ORS can be administered orally in most cases, but nasogastric tube administration is appropriate for children with oral intolerance 6

Key contraindications to ORS include:

• Altered mental status 6
• Inability to tolerate oral or nasogastric fluids 6
• Underlying gastrointestinal problems (ileus, anatomical abnormalities, gut malabsorption) 6

Feeding and Nutrition

Resume normal age-appropriate diet immediately after rehydration—do not withhold food or "rest the bowel" 1, 2

• Breastfed infants should continue nursing on demand throughout the illness 1, 2, 4
• Bottle-fed infants should use full-strength, lactose-free, or lactose-reduced formulas immediately upon rehydration 1
• Begin feeding as soon as appetite returns for children over 4-6 months 1

Critical Pitfalls to Avoid

Do not use soft drinks for rehydration due to high osmolality 1

Do not give antimotility drugs (loperamide) to children under 18 years with acute diarrhea 2

Antiemetics (ondansetron) may be considered only for children over 4 years with severe vomiting to facilitate oral rehydration 2

Maintenance IV Fluids (When ORS Fails)

For isonatremic dehydration: 5% dextrose in 0.45% saline with 20 mEq/L KCl over 24 hours 5

For hyponatremic dehydration: Alternate 0.9% saline and 0.45% saline in 1:1 ratio in 5% dextrose with 20 mEq/L KCl over 24 hours 5

For hypernatremic dehydration: 5% dextrose in 0.2% saline with 20 mEq/L KCl over 2-3 days to avoid cerebral edema 5

When to Seek Immediate Medical Attention

Parents should return immediately if the child becomes unable to tolerate oral fluids, signs of dehydration worsen, diarrhea becomes bloody, or fever increases significantly 2