What is the management of infective acute gastroenteritis?

Management of Infective Acute Gastroenteritis

Oral rehydration solution (ORS) is the first-line treatment for mild to moderate dehydration in both children and adults with acute gastroenteritis, with intravenous fluids reserved only for severe dehydration, shock, or failure of oral therapy. 1, 2

Definition

Acute gastroenteritis is inflammation of the stomach and intestines caused by infectious agents, most commonly viruses, followed by bacteria and parasites. 3 The condition presents with diarrhea, vomiting, and varying degrees of dehydration requiring prompt assessment and rehydration therapy.

Initial Assessment and Hydration Status

Evaluate dehydration severity through specific clinical signs: 1, 2, 4

• Skin turgor - decreased in dehydration
• Mental status - altered with worsening dehydration
• Mucous membrane moisture - dry membranes indicate dehydration
• Capillary refill time - prolonged (>2 seconds) suggests poor perfusion
• Vital signs - tachycardia and hypotension in severe cases
• Urine output - decreased or absent

Categorize dehydration severity: 1, 4

• Mild: 3-5% body weight loss
• Moderate: 6-9% body weight loss
• Severe: ≥10% body weight loss

Rehydration Protocol

Mild to Moderate Dehydration (First-Line)

Use commercially available low-osmolarity ORS (e.g., Pedialyte, CeraLyte) - NOT sports drinks, apple juice, or soft drinks. 2, 1

Dosing: 2, 4

• Children/infants: 50-100 mL/kg over 3-4 hours
• Adolescents/adults: 2-4 L over 3-4 hours
• Alternative for moderate dehydration: 100 mL/kg over 2-4 hours 1

Administration technique for vomiting patients: 1

• Start with small volumes: 5-10 mL every 1-2 minutes using spoon or syringe
• Gradually increase volume as tolerated without triggering vomiting
• This approach successfully rehydrates >90% of children with vomiting and diarrhea without antiemetics 1

Nasogastric ORS administration may be considered for patients who cannot tolerate oral intake or refuse to drink adequately. 1, 2

Replace ongoing losses: 1, 2

• Children <10 kg: 60-120 mL ORS per diarrheal stool/vomiting episode (up to ~500 mL/day)
• Children >10 kg: 120-240 mL ORS per diarrheal stool/vomiting episode (up to ~1 L/day)
• Adolescents/adults: Ad libitum intake up to ~2 L/day

Severe Dehydration (Intravenous Therapy)

Reserve IV fluids for: 1, 2

• Severe dehydration (≥10% body weight loss)
• Shock or altered mental status
• Failure of oral rehydration therapy
• Ileus

IV fluid protocol: 2, 4

• Use isotonic fluids: lactated Ringer's or normal saline
• Administer 20 mL/kg over 30 minutes
• Continue until pulse, perfusion, and mental status normalize (typically 2-4 hours)
• Transition to ORS to replace remaining deficit once patient improves 1

Nutritional Management

Resume feeding early - do not fast or restrict diet: 1, 2, 4

• Continue breastfeeding throughout the diarrheal episode in infants 1, 2, 4
• Resume age-appropriate diet during or immediately after rehydration 1, 2, 4
• Early refeeding reduces severity and duration of illness 1
• Avoid foods high in simple sugars (soft drinks, undiluted apple juice) as they worsen diarrhea through osmotic effects 1

Pharmacological Management

Antiemetics

Ondansetron may be given to children >4 years and adolescents with significant vomiting to facilitate oral rehydration. 1, 2, 4

• Dose: 0.15 mg/kg per dose 2

Antimotility Agents

Loperamide: 1, 2, 4

• Contraindicated in children <18 years with acute diarrhea
• May be given to immunocompetent adults with acute watery diarrhea once adequately hydrated
• Adult dose: 4 mg initially, then 2 mg after each loose stool 2
• Avoid in: inflammatory diarrhea, bloody diarrhea, fever, or suspected toxic megacolon 2

Probiotics and Zinc

• Probiotics may reduce symptom severity and duration in both adults and children 1
• Zinc supplementation reduces diarrhea duration in children 6 months to 5 years in areas with high zinc deficiency or in malnourished children 1, 4

Antimicrobials

Antimicrobial agents have limited usefulness since viral agents are the predominant cause. 1 Consider antimicrobial therapy only in specific cases: 1, 3

• Bloody diarrhea
• Recent antibiotic use (test for Clostridioides difficile)
• Recent foreign travel
• Immunodeficiency
• Severe bacterial infections with positive cultures

Monitoring and Reassessment

Monitor every 2-4 hours: 1

• Vital signs
• Capillary refill
• Skin turgor
• Mental status
• Mucous membrane moisture
• Daily weights to track rehydration progress

Reassess hydration status after 2-4 hours: If still dehydrated, reestimate deficit and restart rehydration. 1

Infection Control Measures

Practice proper hand hygiene: 1, 2, 4

• After using toilet or changing diapers
• Before and after food preparation
• Before eating
• After handling soiled items or animals

Additional measures: 1, 4

• Use gloves and gowns when caring for people with diarrhea
• Clean and disinfect contaminated surfaces promptly
• Separate ill persons from well persons until at least 2 days after symptom resolution

Critical Pitfalls to Avoid

• Do not delay rehydration while awaiting diagnostic testing - initiate promptly 1
• Do not use inappropriate fluids (apple juice, sports drinks, soft drinks) as primary rehydration for moderate to severe dehydration 1, 2
• Do not give antimotility drugs to children or in cases of bloody diarrhea 1, 2
• Do not restrict diet unnecessarily during or after rehydration 1, 2
• Do not rely on antidiarrheal agents as they shift focus away from appropriate fluid, electrolyte, and nutritional therapy 1

Disposition Planning

Plan discharge when: 1

• Tolerating oral intake
• Producing urine
• Clinically rehydrated
• Afebrile for 24 hours (if bacterial infection confirmed)