PE23.{4,6-8} | Acute Gastroenteritis — Summary & Reflection

KEY TAKEAWAYS

Acute gastroenteritis is the most important diarrhoeal syndrome in paediatric practice. Mastering its management requires integrating four clinical domains:

• Define and classify: Diarrhoea = ≥3 loose stools/24h; acute <14 days; watery vs dysentery (blood/mucus); classify dehydration by IMNCI (None/Some/Severe)

• Aetiology and key pathogens:
• Rotavirus = most common severe AGE under 5 (preventable by NIS vaccine)
• V. cholerae = rice-water stools, rapid dehydration, Hanging Drop shows shooting-star motility
• Shigella = dysentery, systemic toxicity, treat with azithromycin
• EHEC O157:H7 = HUS — antibiotics CONTRAINDICATED

• Dehydration assessment (IMNCI): Eyes, skin pinch, drinking, consciousness → None (Plan A) / Some (Plan B: 75 mL/kg/4h) / Severe (Plan C: IV RL 100 mL/kg)

• ORS physiology: Reduced-osmolarity ORS 245 mOsm/L (Na 75, K 20, glucose 75); SGLT1 preserved in secretory diarrhoea → glucose drives Na absorption → ORS works even in cholera

• Zinc: Universal, 20 mg/day (>6 mo) or 10 mg/day (<6 mo) × 14 days full course

• Antibiotics: ONLY for dysentery (azithromycin) or confirmed cholera — NOT routine watery AGE

• Drugs contraindicated: Loperamide (<2 years), antispasmodics (<6 months), routine antiemetics as sole treatment

• Stool investigations: Hanging Drop (fresh stool + saline → V. cholerae shooting-star motility, Giardia tumbling); microscopy (pus cells = invasive; RBCs + trophozoites = amoeba); stool culture for persistent/outbreak; RFT + electrolytes for prerenal AKI pattern

REFLECT

You are deployed as a medical officer to a flood-affected district in India where water supply has been contaminated. There are 12 cases of severe watery diarrhoea presenting to the camp in 24 hours. The IV fluid stock is limited — you have 20 Ringer's Lactate bags and 200 ORS packets.

How would you triage these 12 patients using the IMNCI dehydration criteria to allocate IV fluids only to those who truly need them (Plan C), while managing the others with ORS (Plan B or A)? How would you counsel families on the correct technique for giving ORS — the frequency, the volumes, the importance of not stopping? What public health message about water safety and zinc supplementation would you issue to the community?

Reflect on what it means, in practice, to understand that the most powerful life-saving intervention in this scenario costs less than a cup of tea.