How to Prepare Oral Rehydration Solution (ORS) at Home
Standard WHO-Recommended Recipe
To prepare 1 liter of effective oral rehydration solution, mix the following ingredients in clean water: 3.5 grams sodium chloride (table salt), 2.5 grams sodium bicarbonate (baking soda), 1.5 grams potassium chloride (KCl), and 20 grams glucose (or 40 grams table sugar/sucrose). 1, 2, 3
Practical Measurements for Home Preparation
- ½ teaspoon table salt (provides sodium chloride) 2
- ½ teaspoon baking soda (provides sodium bicarbonate) 2
- ¼ teaspoon salt substitute (provides potassium chloride/KCl) 2
- 4 teaspoons sugar (provides glucose; can use 8 teaspoons table sugar as substitute) 2
- 1 liter clean water (boiled and cooled, or from safe source) 1
For 2 Liters
Double all quantities above to maintain correct electrolyte composition and glucose concentration. 1
Critical Preparation Steps
- Use clean water that has been boiled and cooled, or from a verified safe source to prevent contamination 1
- Measure ingredients accurately - incorrect mixing creates hypertonic solutions that can worsen dehydration and cause hypernatremia 4, 1
- Mix thoroughly until all ingredients completely dissolve 1
- Prepare fresh solution daily and discard any unused portion after 24 hours 1
- Store in a clean, covered container to maintain quality and safety 1
Resulting Electrolyte Composition
This recipe produces a solution with approximately:
- Sodium: 90 mM 1, 2
- Potassium: 20 mM 1, 2
- Chloride: 80 mM 1, 2
- Bicarbonate: 30 mM 1, 2
- Glucose: 111 mM 1, 2
Administration Guidelines
- For mild dehydration (3-5% fluid deficit): Give 50 mL/kg over 2-4 hours 1, 2
- For moderate dehydration (6-9% fluid deficit): Give 100 mL/kg over 2-4 hours 1, 2
- For ongoing losses: Replace 10 mL/kg for each watery stool and 2 mL/kg for each vomiting episode 1, 2
- Provide additional low-sodium fluids (plain water) alongside ORS during maintenance phase to prevent sodium overload 2
Critical Safety Warnings
Never use plain water, tea, or sugar water alone for rehydration - hypotonic fluids worsen fluid losses in high-output diarrhea 1
Severe dehydration (≥10% fluid deficit, shock, altered mental status) requires immediate IV rehydration with Ringer's lactate or normal saline at 20 mL/kg boluses until perfusion normalizes, not oral rehydration 1, 2
Do not add fruit juices to homemade ORS - even small amounts of apple juice or orange juice significantly decrease sodium (-30 to -53 mmol/L) and chloride (-27 to -47 mmol/L) content while increasing osmolality above 311 mOsm/kg, making rehydration less effective 5
Common Pitfalls to Avoid
- Incorrect proportions - the historical experience with commercial preparations in the 1950s showed that incorrect mixing and high carbohydrate concentrations (8%) caused hypernatremia and osmotic diarrhea 4
- Using inappropriate beverages - apple juice, Gatorade, and commercial soft drinks have inappropriate electrolyte content for rehydration 6
- Omitting potassium - potassium replacement is essential for effective rehydration, as demonstrated by Harrison and Darrow in the 1940s 4