What is the appropriate assessment and initial management for a child with suspected food poisoning, including evaluation of severity and red‑flag signs, oral versus intravenous rehydration, use of antidiarrheals and antibiotics, necessary investigations, monitoring, and discharge criteria?

Assessment and Management of Pediatric Food Poisoning

Initial Assessment of Dehydration Severity

Classify dehydration immediately using clinical signs, as this determines all subsequent management decisions. 1

Dehydration Categories

• Mild dehydration (3–5% fluid deficit): increased thirst and slightly dry mucous membranes 1
• Moderate dehydration (6–9% fluid deficit): loss of skin turgor with tenting when pinched, dry mucous membranes, reduced urine output 1
• Severe dehydration (≥10% fluid deficit): severe lethargy or altered consciousness, prolonged skin tenting >2 seconds, cool poorly perfused extremities with delayed capillary refill, rapid deep breathing indicating acidosis 1

Most Reliable Clinical Predictors

• Capillary refill time, prolonged skin retraction, and rapid deep breathing are more reliable than sunken fontanelle or absent tears 1
• Obtain accurate body weight immediately to calculate fluid deficit and monitor response 1

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Red-Flag Signs Requiring Immediate Escalation

Seek emergency care immediately if any of the following are present:

• Bilious (green) vomiting → possible intestinal obstruction requiring urgent surgical evaluation 2
• Bloody stools with high fever and systemic toxicity → bacterial dysentery (Salmonella, Shigella, enterohemorrhagic E. coli); obtain stool culture before antibiotics 2
• Severe dehydration signs (≥10% deficit) → medical emergency requiring immediate IV rehydration 1
• Altered mental status or severe lethargy → indicates severe dehydration or metabolic derangement 1
• Absent bowel sounds → absolute contraindication to oral rehydration 2
• Persistent vomiting despite small-volume ORS → failure of oral rehydration therapy 2

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Rehydration Management

Mild Dehydration (3–5% deficit)

• Administer 50 mL/kg of oral rehydration solution (ORS) containing 50–90 mEq/L sodium over 2–4 hours 1
• Begin with very small volumes (5 mL, one teaspoon) every 1–2 minutes using a spoon, syringe, or medicine dropper 1
• Gradually increase volume as tolerated to prevent triggering vomiting 1

Moderate Dehydration (6–9% deficit)

• Administer 100 mL/kg of ORS over 2–4 hours using the same small-volume technique 1
• If oral intake is not tolerated, consider nasogastric administration at 15 mL/kg/hour 3
• Success rates exceed 90% when proper slow administration technique is used 2

Severe Dehydration (≥10% deficit)

This is a medical emergency requiring immediate hospitalization. 2

• Administer 20 mL/kg boluses of Ringer's lactate or normal saline IV immediately until pulse, perfusion, and mental status normalize 3, 1
• Repeat boluses as needed; may require two IV lines or alternative access (intra-osseous, femoral) 2
• After circulatory stabilization, transition to ORS to replace remaining fluid deficit 1

Ongoing Loss Replacement

• Replace each watery stool with 10 mL/kg of ORS 1
• Replace each vomiting episode with 2 mL/kg of ORS 1
• Continue replacement until diarrhea and vomiting resolve 3

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Reassessment and Monitoring

• Reassess hydration status after 2–4 hours of rehydration therapy 1
• If still dehydrated, recalculate deficit and restart appropriate rehydration 1
• If rehydrated, transition to maintenance phase with ongoing loss replacement 1
• Monitor vital signs, capillary refill, skin turgor, mental status, and urine output 4

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Nutritional Management

Resume age-appropriate diet immediately during or after rehydration is completed—do not withhold food. 3, 2

• Continue breastfeeding without interruption throughout the illness 3, 1
• Resume full-strength formula immediately after rehydration in formula-fed infants 1
• Offer starches (rice, potatoes, noodles), cereals, yogurt, fruits, and vegetables 2
• Avoid foods high in simple sugars (soft drinks, undiluted apple juice, gelatin), high-fat foods, and caffeinated beverages 2
• Early refeeding reduces illness duration and improves nutritional outcomes 2

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Pharmacological Management

Antiemetics

• Ondansetron may be given to children >4 years and adolescents with significant vomiting to facilitate oral rehydration 3
• Dose: 0.15 mg/kg (maximum 16 mg) orally or IV 3
• Reduces vomiting rate, improves ORS tolerance, and decreases need for IV rehydration 3, 5

Antimotility Agents

Loperamide is absolutely contraindicated in all children <18 years of age. 3, 6

• Risk of respiratory depression, serious cardiac adverse reactions, ileus, and death 3, 6
• Serious adverse events occurred in 6 of 28 children in controlled studies 2

Antibiotics

Routine antibiotics are NOT indicated for typical viral gastroenteritis. 2

• Most cases are viral and self-limited 2
• Consider antibiotics ONLY when:
  • Bloody diarrhea with high fever and systemic toxicity 2
  • Watery diarrhea persisting >5 days 2
  • Stool culture identifies treatable bacterial pathogen (Shigella, Salmonella, Campylobacter) 2
  • Immunocompromised patient 3
• Obtain stool culture before starting antibiotics in dysentery cases 2
• Avoid antibiotics if Shiga-toxin-producing E. coli (STEC) O157 is suspected due to risk of hemolytic-uremic syndrome 3

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Laboratory Investigations

Laboratory tests are NOT routinely required for typical gastroenteritis. 7

• Most cases do not require testing as results rarely change management 7
• Consider testing only in:
  • Severe dehydration requiring IV fluids 1
  • Bloody diarrhea with fever 2
  • Immunocompromised patients 3
  • Symptoms persisting >5 days 2
• If indicated, obtain: serum electrolytes, blood gases, renal function, stool culture 8

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Hospitalization Criteria

Admit patients with any of the following:

• Severe dehydration (≥10% deficit) or clinical shock 2
• Failure of oral rehydration therapy despite proper technique 2
• Altered mental status or severe lethargy 2
• Intractable vomiting despite ondansetron 2
• Infants <3 months (lower threshold for complications) 2
• Bloody diarrhea with fever and systemic toxicity (monitor for hemolytic-uremic syndrome) 2
• Significant comorbidities or immunocompromised state 2

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Discharge Criteria

Discharge when the following are met:

• Tolerating oral intake without vomiting 4
• Producing adequate urine output 4
• Clinically rehydrated with normal vital signs 4
• Caregivers demonstrate proper ORS administration technique 2
• No red-flag signs present 1

Discharge Instructions

Provide caregivers with:

• Supply of ORS packets to keep at home 2
• Clear instructions on small-volume (5–10 mL every 1–2 minutes) administration technique 2
• Warning signs requiring immediate return:
  • Bloody diarrhea 1
  • Bilious vomiting 2
  • Decreased urine output (<3 wet diapers in 24 hours) 1
  • Increased lethargy or altered mental status 1
  • High fever 1
  • Worsening dehydration signs 1

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Common Pitfalls to Avoid

• Do NOT delay rehydration while awaiting diagnostic tests 2
• Do NOT use sports drinks, apple juice, or soft drinks as primary rehydration fluids—they lack appropriate electrolyte balance and may worsen diarrhea 2
• Do NOT withhold food or enforce "bowel rest"—this delays recovery and worsens nutritional status 2
• Do NOT rely solely on sunken fontanelle or absent tears for dehydration assessment 1
• Do NOT give antimotility agents (loperamide) to any child <18 years 3, 6
• Do NOT prescribe empiric antibiotics for uncomplicated watery diarrhea—this promotes resistance without benefit 4
• Do NOT allow large-volume rapid drinking from a cup—this triggers vomiting and gives false impression of ORS failure 2