What are the treatment guidelines for moderate dehydration?

Treatment Guidelines for Moderate Dehydration

For children with moderate dehydration, initiate oral rehydration therapy (ORT) with 100 mL/kg of low-osmolarity oral rehydration solution over 3-4 hours as first-line treatment. 1

Initial Assessment and Fluid Deficit Calculation

• Moderate dehydration represents a 6-9% fluid deficit and is characterized by loss of skin turgor, skin tenting when pinched, and dry mucous membranes 1
• Document baseline weight before initiating treatment, as this serves as the most accurate assessment of fluid status 1
• Calculate total rehydration volume: multiply patient's weight in kg by 100 mL (e.g., for an 8.3 kg child, administer 830 mL total) 1

First-Line Treatment: Oral Rehydration Therapy

Administer low-osmolarity ORS containing 45-75 mEq/L of sodium at 100 mL/kg over 3-4 hours. 1, 2

• Acceptable commercial formulations include Pedialyte, CeraLyte, or Enfalac Lytren 1
• ORT demonstrates equal efficacy to IV therapy for moderate dehydration with lower complication rates and faster initiation time (approximately 20 minutes vs 41 minutes for IV) 3
• If the child refuses to drink adequately or cannot tolerate oral intake, use nasogastric administration at 125 mL/hour (15 mL/kg/hour) 1

Evidence Supporting ORT Over IV Therapy

The American Academy of Pediatrics strongly recommends ORT as first-line therapy based on randomized controlled trials showing 50% success rates for both ORT and IV therapy at 4 hours, but with ORT requiring less time to initiate and resulting in fewer hospitalizations (30.6% vs 48.7%) 3. The failure rate of ORT in moderate dehydration ranges from 17.6% overall, with higher rates only in severely acidotic patients 4.

When to Escalate to IV Therapy

Switch to isotonic IV fluids if any of the following occur: 1

• ORS therapy fails after 3-4 hours
• Signs of severe dehydration develop during treatment
• Persistent severe vomiting prevents oral or NG intake
• Clinical evidence of ileus (contraindication to ORT) 5

IV Rehydration Protocol

• Administer 20 mL/kg bolus of isotonic fluid (lactated Ringer's or 0.9% saline) until pulse, perfusion, and mental status normalize 5, 1
• For children >10 kg with signs of shock, initial boluses of 20 mL/kg may be repeated as needed 5
• Continue IV rehydration until there is no evidence of ileus and vital signs stabilize 5

Maintenance Phase After Rehydration

Reassess hydration status after 3-4 hours by checking weight, clinical signs, and urine output. 1

• Resume age-appropriate normal diet immediately once rehydration is complete, which shortens the duration of diarrhea 1
• Continue breastfeeding throughout the illness if applicable 1
• Continue regular lactose-containing formula if formula-fed 1
• Replace ongoing losses with 60-120 mL ORS for each diarrheal stool or vomiting episode (for children <10 kg body weight), up to approximately 500 mL/day 1

Monitoring Requirements

• Check vital signs every 2-4 hours initially 1
• Maintain strict intake and output documentation 1
• Obtain daily weights 1
• Monitor for signs of worsening dehydration or development of complications 1

Electrolyte Management

• Monitor and replace potassium, sodium, and other electrolytes as needed 5
• Check serum electrolytes if clinical signs suggest abnormalities 5
• Addition of 20 mEq/L potassium to rehydration solutions permits repair of cellular potassium deficits without risk of hyperkalemia 2
• The degree of acidosis is more predictive of ORT failure than other electrolyte disturbances; severely acidotic patients have higher failure rates (38%) and longer rehydration times 4

Critical Medications to AVOID

Never administer antimotility drugs (loperamide) in children <18 years with acute diarrhea, as they are contraindicated and can lead to paralytic ileus and severe complications. 5, 1

• Discontinue anticholinergic, antidiarrheal, and opioid agents, as they aggravate ileus 5

Common Pitfalls to Avoid

• Do not rely solely on sunken fontanelle or absence of tears as indicators of dehydration, as they are less reliable 1
• Do not rush to IV therapy when ORT is appropriate, as ORT is equally effective with lower complication rates 1, 3
• Do not withhold feeding after rehydration is complete, as early refeeding shortens illness duration 1
• Do not use ORT in the presence of ileus, as it fails in this setting and can worsen abdominal distention 5