Low Osmolarity Oral Rehydration Solution (ORS)
Low osmolarity ORS is the current global gold standard for the management of acute diarrhea in children, as recommended by WHO and UNICEF. It replaces the older, higher-osmolarity formulations to reduce stool volume and the need for IV therapy.
1. Composition (WHO Standard)
| Component | Concentration (mmol/L) |
|---|---|
| Sodium | 75 |
| Glucose | 75 |
| Chloride | 65 |
| Potassium | 20 |
| Citrate | 10 |
| Total Osmolarity | 245 mOsm/L |
2. Why “Low” Osmolarity?
- Reduced Stool Output: Lower salt and sugar concentrations decrease the osmotic load in the gut, reducing water loss.
- Less Vomiting: Facilitates faster gastric emptying.
- Decreased Need for IV Therapy: Superior efficacy in correcting dehydration compared to the original 311 mOsm/L formulation.
NEET PG Hint: Remember the exact total osmolarity: 245 mOsm/L. This is a very frequently tested value. Also, note that the ratio of Sodium to Glucose is **1:1**, which is crucial for optimal Sodium-Glucose cotransport in the enterocytes.