WHO ORS & Dehydration Fluid Calculator for Pakistan
Calculate exact oral rehydration solution (ORS) volumes in mL for the first 4 hours (WHO Plan B: 75 mL/kg), ongoing stool-by-stool replacement (Plan A), and paediatric zinc sulfate dosing.
Clinical Quick Rule · WHO Low-Osmolarity ORS (245 mOsm/L)
For mild-to-moderate dehydration (WHO Plan B), give 75 mL of ORS per kg of body weight over 4 hours (e.g., 750 mL over 4 hours for a 10 kg toddler), plus 50–100 mL (<2 yrs) or 100–200 mL (2–10 yrs) after each loose stool, alongside 10–20 mg daily oral zinc for 14 days.
WHO Plan B — 4-Hour Oral Rehydration Therapy (75 mL/kg)
First 4-Hour Rehydration
900 mL
Range: 600–1200 mL over 4 hrs
After Every Loose Stool
50–100 mL
~300 mL for 4 loose stools
WHO Zinc Adjunct
20 mg / day
Give for 14 days (cuts recurrence)
- • Give small sips from a cup or spoon every 1–2 minutes. If the patient vomits, wait 10 minutes and resume more slowly.
- • Reassess hydration status after 4 hours. Seek medical care immediately if eyes remain sunken, skin pinch goes back slowly, or the child cannot drink.
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Comparison: WHO Low-Osmolarity ORS vs Soft Drinks & Home Fluids
Why standard WHO 245 mOsm/L ORS sachets outperform sodas, packaged juices, and plain water during acute diarrhoea or Pakistani summer heatwaves.
| Fluid Type | Sodium (mmol/L) | Glucose (mmol/L) | Total Osmolarity | Clinical Verdict |
|---|---|---|---|---|
| WHO Low-Osmolarity ORS Sachet | 75 mmol/L | 75 mmol/L | 245 mOsm/L | Gold standard — optimal 1:1 sodium-glucose cotransport |
| Carbonated Soft Drinks (7-Up / Sprite) | 2–4 mmol/L | 550–700 mmol/L | >650 mOsm/L | Avoid — high sugar triggers osmotic diarrhoea & worsens sodium loss |
| Packaged Apple / Mango Juice | <5 mmol/L | 600+ mmol/L | >700 mOsm/L | Avoid in acute diarrhoea — lacks sodium & increases stool output |
| Salted Lassi / Rice Kanji / Yakhni | Variable (30–50) | Starch polymers | ~200–260 mOsm/L | Safe Plan A home adjunct alongside WHO ORS sachets |
Frequently Asked Questions — ORS & Dehydration in Pakistan
How much ORS should I give a child with diarrhoea in Pakistan?
Under WHO/UNICEF Integrated Management of Childhood Illness (IMCI) guidelines, if there is no visible dehydration (Plan A), give 50–100 mL of low-osmolarity ORS after every loose stool for children under 2 years, and 100–200 mL after every loose stool for children aged 2–10 years. If the child has some dehydration (Plan B: restless, thirsty, sunken eyes), give 75 mL per kg of body weight over the first 4 hours in small sips.
How do I mix a standard ORS packet in Pakistan?
A standard Pakistani WHO low-osmolarity ORS sachet (such as Pedialyte/ORS-L/Nimkol standard 1-litre packet) must be dissolved in exactly 1,000 mL (1 litre, or 4 standard 250 mL glasses) of clean, boiled-and-cooled water. Never boil the water after adding the ORS powder, and never mix a 1-litre sachet into a half-litre bottle, as overly concentrated sodium can cause hypernatraemia.
Why does WHO recommend Zinc syrup alongside ORS for children?
Clinical trials across South Asia show that giving oral zinc sulfate or zinc gluconate (10 mg daily for infants under 6 months; 20 mg daily for children 6 months to 10 years) for 10 to 14 days shortens the duration of acute diarrhoea by ~25% and reduces the risk of repeat diarrhoeal episodes over the following 2 to 3 months.
Can I give 7-Up, Sprite, or packaged fruit juice instead of ORS?
No. Carbonated soft drinks and commercial fruit juices contain very high simple sugar (high osmolarity) and almost no sodium or potassium. High sugar pulls water into the gut lumen via osmosis (osmotic diarrhoea), worsening fluid loss and electrolyte imbalance, especially in young children.
When is diarrhoea an emergency requiring hospital IV fluids (WHO Plan C)?
Go to the nearest hospital emergency department immediately if the child or adult is lethargic or unconscious, unable to drink or drinking poorly, vomiting everything, has sunken eyes with absent tears, skin pinch that goes back very slowly (>2 seconds), bloody stools (dysentery), high fever, or no urination for 6+ hours.