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PE23.{4,6-8} | Acute Gastroenteritis — SDL Guide (Part 3)

Self-Assessment: Clinical Application

Apply the complete clinical framework — assessment, investigation, and management — to these scenarios.

Scenario 1 — Stool Examination: A community cholera outbreak has been reported. A 6-year-old girl presents with 12 hours of profuse watery diarrhoea, described as pale and watery with some whitish flecks. She is lethargic, cannot drink, and her skin pinch tents for >2 seconds. You have received a fresh stool specimen.
Stool examination plan: Perform a Hanging Drop Preparation — place a drop of fresh stool and a drop of normal saline on a slide, cover, and examine under high power immediately. Look for comma-shaped curved rods with rapid 'shooting star' darting motility, confirming V. cholerae. Send for culture and sensitivity.
Management: This child has SEVERE dehydration → Plan C. IV Ringer's Lactate: 30 mL/kg in 30 minutes (≥12 months), then 70 mL/kg in 2.5 hours. Start ORS as soon as she can drink (5 mL/kg/hour alongside IV). Single-dose azithromycin 20 mg/kg once cholera confirmed or strongly suspected. Zinc 20 mg/day × 14 days.

Scenario 2 — Dysentery with HUS: A 3-year-old boy has had 5 days of bloody diarrhoea. He is now pale, jaundiced, and has reduced urine output. His RFT shows urea 48 mg/dL, creatinine 2.1 mg/dL (elevated for age). Blood film shows fragmented red cells. Platelet count 45,000/mm³.
Discussion: This is haemolytic uraemic syndrome (HUS) — the classic triad of microangiopathic haemolytic anaemia + thrombocytopenia + AKI, here following bloody diarrhoea consistent with EHEC O157:H7. CRITICALLY: do NOT give antibiotics — in EHEC, antibiotics increase Shiga toxin release and worsen HUS. Refer urgently to paediatric nephrology. Management: supportive — IV fluids, blood transfusion for anaemia, dialysis if renal failure persists.

Scenario 3 — Zinc question: A mother was given zinc tablets for her 8-month-old who had diarrhoea. The diarrhoea resolved after 3 days. She stops the zinc, thinking it is no longer needed. Is she correct?
Discussion: No — zinc should be continued for the full 14 days even after diarrhoea resolves. The 14-day course replenishes body zinc stores and reduces the risk of future diarrhoeal episodes and respiratory infections. The dose for an 8-month-old (>6 months) is 20 mg elemental zinc per day. Stopping early at symptom resolution is the most common error in zinc supplementation.