From the Guidelines
Oral rehydration solution (ORS) should be administered at 50-100 mL/kg over 3-4 hours for children with mild to moderate dehydration, typically 1-2 mL/kg after each diarrheal stool or vomiting episode for ongoing losses, as recommended by the 2017 Infectious Diseases Society of America clinical practice guidelines 1. For adults, 2-3 liters should be consumed over 24 hours, or approximately 200-400 mL after each loose stool. Standard ORS contains sodium, potassium, chloride, citrate, and glucose to facilitate intestinal absorption of water and electrolytes through the sodium-glucose cotransport mechanism. The glucose component is essential as it enables sodium absorption, which then creates an osmotic gradient for water absorption. For children under 2 years, administer small amounts (1-2 teaspoons) every 1-2 minutes to improve tolerance. Commercially available solutions like Pedialyte, Infalyte, or WHO-formulated ORS are recommended, though homemade solutions can be prepared in emergencies using 6 teaspoons of sugar, 1/2 teaspoon of salt in 1 liter of clean water. Continue regular feeding during rehydration therapy, as maintaining nutrition supports intestinal recovery and immune function.
Key Considerations
- The American Academy of Pediatrics recommends that oral solutions used for rehydration should contain 75-90 mEq/L of sodium 1.
- Reduced osmolarity oral rehydration solution (ORS) is recommended as the first-line therapy of mild to moderate dehydration in infants, children, and adults with acute diarrhea from any cause 1.
- Nasogastric administration of ORS may be considered in infants, children, and adults with moderate dehydration, who cannot tolerate oral intake, or in children with normal mental status who are too weak or refuse to drink adequately 1.
- Isotonic intravenous fluids such as lactated Ringer’s and normal saline solution should be administered when there is severe dehydration, shock, or altered mental status and failure of ORS therapy 1.
Administration Guidelines
- For children with mild to moderate dehydration, administer ORS at 50-100 mL/kg over 3-4 hours 1.
- For adults, consume 2-3 liters over 24 hours, or approximately 200-400 mL after each loose stool.
- Replace ongoing losses in stools with ORS until diarrhea and vomiting are resolved 1.
From the Research
Oral Rehydration Solution Doses for Pediatrics
- The recommended dose of oral rehydration solution (ORS) for children with acute watery diarrhea and moderate dehydration is 24.4 ml/kg, as tolerated by the child 2.
- A study found that children who tolerated a median of 25.8 ml/kg of ORS were more likely to improve and have reduced diarrhea, compared to those who tolerated only 11.1 ml/kg of ORS 2.
- Another study compared the effectiveness of ORT and IVF in moderately dehydrated children and found that ORT was as effective as IVF, with half of the children in both groups being rehydrated successfully at 4 hours 3.
Oral Rehydration Solution Doses for Adults
- There is limited information available on the recommended dose of ORS for adults.
- However, the same principles of ORS treatment can be applied to adults, with the goal of replacing lost fluids and electrolytes 4, 5, 6.
Comparison of Different Oral Rehydration Solutions
- Studies have compared the effectiveness of different ORS solutions, including those with 90 mmol/L of sodium and those with reduced osmolarity (75 mmol/L of sodium) 4, 5, 6.
- The results suggest that reduced osmolarity ORS solutions may be safer and more effective in treating acute diarrhea in children, with reduced stool output and vomiting 5.
- However, more research is needed to determine the optimal ORS solution for adults and children with different types of dehydration and underlying health conditions.