Paediatric Dehydration: Assessment, ORS & WHO Plan A/B/C

Diarrhoea with dehydration is one of the leading causes of death in children under five worldwide — and in India, it remains a major public health emergency. The WHO estimates that diarrhoeal diseases cause approximately 525,000 child deaths per year globally, with South Asia bearing a disproportionate burden. In India, acute diarrhoea accounts for roughly 13% of under-5 mortality.

The good news: most of these deaths are entirely preventable with timely, correct oral rehydration. The WHO-developed approach — assessing dehydration with four clinical signs and matching treatment to severity with Plans A, B, or C — has saved tens of millions of lives since its introduction. Every parent, every frontline health worker, and every doctor needs to know this framework.

Why Children Dehydrate So Rapidly

Children — especially infants and toddlers — are far more vulnerable to dehydration than adults, for several physiological reasons:

• Higher body water percentage: Infants are approximately 75–80% water by body weight (adults ~60%). Even a small absolute fluid loss represents a larger percentage of total body water.
• Higher surface area to weight ratio: Greater insensible water loss through skin and respiration relative to body size.
• Greater daily fluid turnover: Infants turn over approximately 15% of their total body water daily (adults ~4%).
• Cannot communicate thirst: Infants cannot tell you they are thirsty or ask for water, making dehydration easy to miss until advanced.
• Limited physiological reserve: Children compensate less effectively than adults — once compensation fails, deterioration is rapid.

The WHO 4-Sign Dehydration Assessment

The WHO Integrated Management of Childhood Illness (IMCI) guidelines use four clinical signs to classify dehydration severity. These can be assessed in under two minutes at any bedside, health post, or outpatient setting — no laboratory tests required.

Scoring: Each sign is scored 0, 1, or 2. Total score guides the WHO treatment plan:

• Score 0–1: No dehydration → Plan A
• Score 2–4: Some dehydration → Plan B
• Score 5–8: Severe dehydration → Plan C

WHO Rehydration Plans

Plan A — Home Treatment (No / Minimal Dehydration)

• ORS for ongoing losses: Give 10 mL/kg ORS for each loose stool passed. For children under 2 years: 50–100 mL per stool. For children 2–10 years: 100–200 mL per stool.
• Continue breastfeeding throughout — do not stop breast milk for diarrhoea
• Continue age-appropriate feeding — do not withhold food. The old advice of "starving" a child with diarrhoea is wrong and harmful.
• Zinc supplementation — 20 mg/day for children ≥ 6 months, 10 mg/day for infants < 6 months, for 10–14 days
• Return immediately if: child cannot drink, develops bloody stools, high fever, repeated vomiting, or appears more unwell

Plan B — Supervised ORS at Health Facility (Some Dehydration)

• ORS volume: 75 mL/kg over 4 hours — give slowly by spoon or cup, not bottle. If vomiting, reduce to 5 mL every 1–2 minutes by syringe.
• Reassess for dehydration signs every 1–2 hours during rehydration
• If child vomits persistently and cannot retain oral ORS: insert a nasogastric tube and give ORS at 20 mL/kg/hour via NG
• After 4 hours, reassess: if rehydrated → switch to Plan A; if still some dehydration → repeat Plan B; if worsened → Plan C
• Do not give IV fluids in Plan B unless child cannot retain oral/NG ORS or deteriorates
• Give zinc and continue feeding once rehydrated

Plan C — IV Rehydration (Severe Dehydration)

Severe dehydration is a medical emergency. IV access must be established immediately.

• Fluid of choice: Ringer's Lactate (Hartmann's Solution). If unavailable: normal saline (0.9% NaCl). Do NOT use 5% dextrose alone — it provides no electrolyte replacement.
• Total volume: 100 mL/kg, divided as follows:
  • Children ≥ 12 months: 30 mL/kg over 30 minutes, then 70 mL/kg over 2.5 hours
  • Infants < 12 months: 30 mL/kg over 1 hour, then 70 mL/kg over 5 hours
• Reassess every 15–30 minutes. If improving: continue. If not improving after first 30 min: increase rate.
• Start ORS (5 mL/kg/hour) as soon as the child can drink — usually 3–4 hours after IV started
• Once the child can drink freely and dehydration has resolved: switch to Plan B, then Plan A
• Monitor for: hypoglycaemia (check BGL), electrolyte abnormalities (Na, K), and signs of fluid overload

ORS — Oral Rehydration Solution

ORS is one of the greatest medical achievements of the 20th century. The WHO/UNICEF low-osmolarity ORS formula (introduced in 2003) has the following composition per litre of clean water:

Standard ORS sachets (Electral, Pedialyte, WHO-ORS) available throughout India follow this formula. Always prepare ORS with the correct amount of water — too concentrated ORS can worsen dehydration.

Home-Made ORS (Emergency Use Only)

When commercial ORS is not available: dissolve 6 level teaspoons of sugar + ½ teaspoon of salt in 1 litre of clean water. This is a temporary measure — obtain commercial ORS as soon as possible. Home-made ORS is less precise and should not be used long-term.

Zinc Supplementation — Why It Matters

WHO and UNICEF recommend zinc for every child with diarrhoea. The evidence is strong:

• Reduces duration of diarrhoeal episode by approximately 25%
• Reduces stool output and frequency
• Reduces risk of subsequent diarrhoeal episodes for up to 3 months after treatment
• Reduces all-cause child mortality when given with ORS

Dose: 20 mg/day for children ≥ 6 months; 10 mg/day for infants < 6 months. Duration: 10–14 days. Available as dispersible tablets (Zincovit, Zinconia) or syrup throughout India. In India and South Asia, zinc supplementation is part of national diarrhoea management guidelines and available free at government health facilities.

Antibiotics in Acute Diarrhoea — When to Use and When Not To

Most acute diarrhoea in children is viral (rotavirus, norovirus) and does not require antibiotics. Antibiotic overuse in diarrhoea is a major driver of antimicrobial resistance in India.

Antibiotics ARE indicated in:

• Bloody diarrhoea (dysentery) — empirical treatment with azithromycin or ciprofloxacin; send stool culture
• Suspected cholera (rice-water stools in epidemic context) — doxycycline or azithromycin
• Proven Giardia or Entamoeba histolytica on stool microscopy — metronidazole
• Diarrhoea with fever in a child < 3 months — consider sepsis workup and empirical antibiotics

Antibiotics are NOT indicated for watery diarrhoea without blood or proven bacterial cause. Anti-motility agents (loperamide) are contraindicated in children — they cause paralytic ileus and increase risk of systemic infection.

Signs That Require Immediate Hospital Referral

• Lethargy, loss of consciousness, or convulsions
• Unable to drink or retain any fluids despite attempts
• Sunken eyes + not drinking
• Persistent high fever (> 38.5°C in infant < 3 months; > 39°C in any child)
• Bloody diarrhoea or blood in vomit
• Suspected surgical cause (bilious vomiting, severe abdominal distension, no stool passage)
• Signs of severe malnutrition (visible wasting, oedema of feet)

This article is for educational purposes based on WHO IMCI and IAP guidelines. Management of severely dehydrated children requires immediate medical assessment. Always seek professional medical care for a child who is unwell.

Built by an MBBS, AFIH Certified Physician in Punjab, India | RxMedCalc.com