Severity Classification of Acute Gastroenteritis in Pediatric Patients
The severity of acute gastroenteritis (AGE) in children is classified based on the degree of dehydration: mild (3-5% fluid deficit), moderate (6-9% fluid deficit), and severe (≥10% fluid deficit), determined primarily through clinical assessment of specific physical examination findings. 1
Clinical Assessment Framework
The most accurate assessment of fluid status is acute weight change compared to premorbid weight, though this is often unavailable in practice. 1 When premorbid weight is unknown, specific clinical signs provide reliable assessment of dehydration severity. 1
Mild Dehydration (3-5% Fluid Deficit)
Clinical Features:
- Increased thirst 1
- Slightly dry mucous membranes 1
- Normal mental status 2
- Normal skin turgor 2
- Normal vital signs 2
Management Implications:
- Oral rehydration solution (ORS) at 50 mL/kg over 2-4 hours 2
- Can typically be managed at home 3
- Continue age-appropriate diet 2
Moderate Dehydration (6-9% Fluid Deficit)
Clinical Features:
- Loss of skin turgor with tenting when pinched 1
- Dry mucous membranes 1
- Decreased urine output 2
- Mild tachycardia 2
- Normal or slightly altered mental status 1
Management Implications:
- ORS at 100 mL/kg over 2-4 hours 2
- Replace ongoing losses: 10 mL/kg for each watery stool, 2 mL/kg for each vomiting episode 2
- Consider ondansetron (>4 years) to facilitate oral rehydration if vomiting is significant 2
- Reassess after 2-4 hours; if still dehydrated, reestimate deficit and restart rehydration 2
Severe Dehydration (≥10% Fluid Deficit)
Clinical Features:
- Severe lethargy or altered state of consciousness 1
- Prolonged skin tenting with skin retraction time >2 seconds 1
- Cool and poorly perfused extremities 1
- Decreased capillary refill 1
- Rapid, deep breathing (indicating metabolic acidosis) 2
- Tachycardia or hypotension 2
- Absent or minimal urine output 2
Management Implications:
- Immediate intravenous rehydration with isotonic fluids (lactated Ringer's or normal saline) is mandatory 2
- Hospitalization required 2
- Continue IV therapy until pulse, perfusion, and mental status normalize 2
- Transition to ORS once patient improves 2
Most Reliable Clinical Predictors
The following physical findings are most reliably predictive of significant dehydration severity: 1
- Prolonged skin retraction time (>2 seconds) - most reliable single predictor 1, 2
- Rapid, deep breathing - indicates metabolic acidosis 1
- Capillary refill time - good correlation with fluid deficit (though affected by fever, ambient temperature, and age) 1
Less reliable signs include sunken fontanelle or absence of tears. 1
Critical Pitfalls to Avoid
Do not underestimate dehydration in infants, who are more prone to rapid dehydration due to higher body surface-to-weight ratio, higher metabolic rate, and dependence on caregivers for fluid intake. 1
Absent bowel sounds on auscultation is an absolute contraindication to oral rehydration - oral fluids should not be given until bowel sounds return. 2
Do not delay rehydration therapy while awaiting diagnostic testing - rehydration should be initiated promptly based on clinical assessment. 2
Stool output >10 mL/kg/hour is associated with lower success rates of oral rehydration, though ORT should still be attempted before escalating to IV therapy. 2
High-Risk Features Requiring Lower Threshold for Escalation
Even with mild-moderate initial presentation, certain features warrant closer monitoring and lower threshold for intervention: 2
- Infants <3 months of age 2
- Immunocompromised patients 2
- Bloody stools with fever and systemic toxicity (may indicate Salmonella, Shigella, or enterohemorrhagic E. coli) 2
- Persistent vomiting despite small-volume ORS administration (5-10 mL every 1-2 minutes) 2
- Failure to improve after initial 2-4 hour rehydration attempt 2