What is the management for a pediatric patient with Acute Gastroenteritis (AGE) and dehydration?

Management of Pediatric Acute Gastroenteritis with Dehydration

For pediatric patients with AGE and dehydration, oral rehydration solution (ORS) is the first-line treatment for mild-to-moderate dehydration, while severe dehydration requires immediate intravenous resuscitation. 1, 2

Initial Assessment

Assess dehydration severity through physical examination focusing on reliable clinical indicators:

• Mild dehydration (3-5% fluid deficit): Increased thirst and slightly dry mucous membranes 1, 3
• Moderate dehydration (6-9% fluid deficit): Loss of skin turgor, skin tenting when pinched, and dry mucous membranes 1, 2
• Severe dehydration (≥10% fluid deficit): Severe lethargy or altered consciousness, prolonged skin tenting (>2 seconds), cool and poorly perfused extremities, decreased capillary refill 1, 3

The most reliable predictors of significant dehydration are rapid deep breathing (indicating acidosis), prolonged skin retraction time, and decreased perfusion—more so than sunken fontanelle or absent tears. 1, 3

• Obtain accurate body weight and assess capillary refill time, though recognize that fever, ambient temperature, and age can affect this measurement 1, 3
• Laboratory studies are rarely needed; reserve serum electrolytes for clinical signs suggesting abnormal sodium/potassium concentrations 1
• Stool cultures are indicated only for dysentery (bloody diarrhea), not routine watery diarrhea 1

Rehydration Protocol by Severity

Mild Dehydration (3-5% Deficit)

Administer ORS containing 50-90 mEq/L sodium at 50 mL/kg over 2-4 hours: 1, 3

• Start with small volumes (one teaspoon) using a teaspoon, syringe, or medicine dropper 1, 2
• Gradually increase the amount as tolerated 1, 2
• Reassess hydration status after 2-4 hours 1
• If rehydrated, progress to maintenance phase; if still dehydrated, reestimate deficit and restart rehydration 1

Moderate Dehydration (6-9% Deficit)

Administer ORS containing 50-90 mEq/L sodium at 100 mL/kg over 2-4 hours using the same small-volume technique: 1, 2

• Use the same gradual escalation approach as mild dehydration 1, 2
• For infants unable to drink but not in shock, nasogastric tube administration at 15 mL/kg/hour is an effective alternative 2
• Research suggests that children who tolerate at least 25 mL/kg of ORS during the initial 2-4 hour period have an 80% success rate with outpatient oral rehydration 4
• Common pitfall: Children tolerating less than 11-18 mL/kg during the initial ORS trial have higher failure rates and may require closer monitoring or IV therapy 4, 5

Severe Dehydration (≥10% Deficit)

This constitutes a medical emergency requiring immediate IV rehydration: 1, 3

• Administer boluses of 20 mL/kg of Ringer's lactate solution or normal saline until pulse, perfusion, and mental status normalize 1, 3
• May require two IV lines or alternate access sites (venous cutdown, femoral vein, intraosseous infusion) 1
• Once level of consciousness returns to normal, the patient can take remaining estimated deficit by mouth 1
• Critical consideration: Children with serum bicarbonate ≤13 mEq/L are more likely to fail oral rehydration after initial IV stabilization and may require prolonged IV therapy 5

Replacement of Ongoing Losses

During both rehydration and maintenance phases, continuously replace ongoing stool and vomit losses: 1, 2

• For measured losses: 1 mL of ORS for each gram of diarrheal stool 1
• For approximated losses: 10 mL/kg ORS for each watery/loose stool and 2 mL/kg for each vomiting episode 1, 2
• Age-specific volumes:
  • Children <2 years: 50-100 mL ORS after each stool 2
  • Children >2 years: 100-200 mL ORS after each stool 2
  • Infants <10 kg: 60-120 mL ORS per episode, up to ~500 mL/day 2

Dietary Management

Continue feeding throughout illness—do not "rest the bowel": 2, 3

• Breastfed infants: Continue nursing on demand without interruption 1, 2, 3
• Bottle-fed infants: Resume full-strength, lactose-free or lactose-reduced formulas immediately upon rehydration 1, 2, 3
• When lactose-free formulas are unavailable, full-strength lactose-containing formulas can be used under supervision 1
• Children >4-6 months: Offer age-appropriate foods every 3-4 hours as tolerated 2, 3
• Lactose intolerance diagnosis: Only indicated by worsening diarrhea upon lactose introduction, not by stool pH <6.0 or reducing substances >0.5% alone 1

Monitoring and Reassessment

Regularly assess response to therapy: 2

• Monitor skin turgor, mucous membrane moisture, and mental status 2
• Track stool frequency and consistency 2
• Measure weight changes throughout therapy 2
• Monitor urine output 2

Predictors of oral rehydration failure include: 6

• Higher Manchester Triage System urgency level 6
• Abnormal capillary refill time 6
• Higher clinical dehydration scale score 6

When to Switch to IV Therapy

Indications for IV rehydration include: 2

• Progression to severe dehydration with shock or altered mental status 2
• Inability to protect airway 2
• Ileus preventing oral intake 2
• Failed oral rehydration therapy despite adequate trial 2
• Persistent vomiting after initial ORS trial (occurs in approximately 21-28% of cases) 6, 5

Appropriate ORS Selection

Use low-osmolarity ORS containing 50-90 mEq/L sodium for all age groups: 1, 2

• Commercial formulations include Pedialyte, CeraLyte, and Enfalac Lytren 2
• Avoid soft drinks for rehydration due to high osmolality 3
• Do not use anti-diarrheal agents—they are contraindicated 3

Key Clinical Pearls

• Approximately 72-79% of children with moderate dehydration can be successfully managed with oral rehydration alone 5, 7
• ORT results in shorter emergency department stays (225 vs 358 minutes), less staff time (36 vs 65 minutes), and higher parental satisfaction (77% vs 37.5%) compared to IV therapy 7
• The 21% failure rate of oral rehydration emphasizes the importance of early recognition of risk factors 6
• No mortality has been reported in comparative studies of rapid versus slower IV rehydration rates, though most evidence comes from moderate dehydration cases 8