Oral rehydration therapy is effective, safe, convenient, and inexpensive compared with IV therapy. Oral rehydration therapy is recommended by the American Academy of Pediatrics and the World Health Organization (WHO) and should be used for children with mild to moderate dehydration who are accepting fluids orally unless prohibited by copious vomiting or underlying disorders (eg, surgical abdomen, intestinal obstruction) (1). In this situation, oral rehydration therapy has a failure rate of < 5% (2). Since the WHO adopted recommendations for oral rehydration therapy in the 1970s, globally > 1 million deaths per year may have been prevented (3).
(See also Dehydration in Children.)
General references
1. American Academy of Pediatrics, Provisional Committee on Quality Improvement, Subcommittee on Acute Gastroenteritis. Practice parameter: the management of acute gastroenteritis in young children. Pediatrics. 1996;97(3):424-435.
2. Bellemare S, Hartling L, Wiebe N, et al. Oral rehydration versus intravenous therapy for treating dehydration due to gastroenteritis in children: a meta-analysis of randomised controlled trials. BMC Med. 2004;2:11. Published 2004 Apr 15. doi:10.1186/1741-7015-2-11
3. WHO/Unicef. Clinical management of acute diarrhoea: WHO/Unicef joint statement. 2004. Accessed December 17, 2024.
Solutions for Oral Rehydration Therapy
Oral rehydration solution (ORS) should contain a combination of glucose and sodium to take advantage of the sodium-glucose cotransport in the gut and improve absorption. ORS are widely available and come as premixed commercial solutions or as powders that are mixed with tap water. Reduced osmolarity ORS recommended by the WHO since 2002 has the following composition (1):
Glucose 75 mEq/L (75 mmol/L) as either glucose-based or polymer-based (rice, wheat, or corn) solutions
Sodium 75 mEq/L (75 mmol/L)
Total osmolarity 245 mEq/L (245 mmol/L)
Sports drinks, sodas, juices, and similar drinks do not meet these criteria and should not be used. They generally have too little sodium and too much carbohydrate to take advantage of sodium/glucose cotransport, and the osmotic effect of the excess carbohydrate may result in additional fluid loss. The sodium/glucose cotransport in the gut is optimized with a sodium:glucose ratio of 1:1.
Premixed commercial rehydration solutions are readily available in many pharmacies and supermarkets. These solutions are effective despite having a sodium:glucose ratio of approximately 1:3.
Solutions reference
1. Powers KS. Dehydration: Isonatremic, Hyponatremic, and Hypernatremic Recognition and Management [published correction appears in Pediatr Rev. 2015 Sep;36(9):422. doi: 10.1542/pir.36-9-422]. Pediatr Rev. 2015;36(7):274-285. doi:10.1542/pir.36-7-274
Administration of Oral Rehydration Therapy
Generally, 50 mL/kg is given over 4 hours for mild dehydration and 100 mL/kg for moderate dehydration. For each diarrheal stool, an additional 10 mL/kg (up to 240 mL) is given. After 4 hours, the patient is reassessed. If signs of dehydration persist, the same volume is repeated.
Vomiting usually should not deter oral rehydration therapy (unless there is bowel obstruction or other contraindication to taking fluid by mouth) because vomiting typically abates over time. Small, frequent amounts are used, starting with 5 mL every 5 minutes and increasing gradually as tolerated. The calculated volume required over a 4-hour period can be divided into 4 separate aliquots. These 4 aliquots can then be divided into 12 smaller aliquots and given every 5 minutes over the course of an hour with a syringe if needed.
Once the deficit has been replaced, an oral rehydration solution is continued and children should begin eat an age-appropriate diet as soon as possible once they have stopped vomiting. Infants may resume breastfeeding (chestfeeding) or formula (1).
Administration reference
1. Gregorio GV, Dans LF, Silvestre MA. Early versus Delayed Refeeding for Children with Acute Diarrhoea. Cochrane Database Syst Rev. 2011;2011(7):CD007296. Published 2011 Jul 6. doi:10.1002/14651858.CD007296.pub2
