Issue: December 2010
December 01, 2010
6 min read

ORS for dehydration: Are you using it?

Issue: December 2010
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The viral season will usher in not only increases in respiratory tract infections but also viral gastrointestinal infections (acute gastroenteritis), often resulting in diarrhea and the potential for dehydration.

Edward A. Bell, PharmD, BCPS
Edward A. Bell

Diarrheal diseases and dehydration are major causes of pediatric morbidity and mortality throughout the world. More than 2 million deaths are estimated to occur worldwide in young children (younger than 5 years) because of diarrheal diseases. Fortunately, deaths in the United States occur less commonly, although they remain significant. Diarrheal diseases result in 200,000 US hospitalizations and 300 pediatric deaths annually. The use of oral rehydration solutions (ORS) has reduced death caused by dehydration worldwide during the past 25 years, but evidence exists that ORS are underutilized in the United States.

Guidelines on use of ORS

Recently, the AAP updated its guidelines on the treatment of acute gastroenteritis and dehydration. In 2004, the AAP endorsed and adopted treatment recommendations by the CDC, as published in a Morbidity and Mortality Weekly Report in 2003. These guidelines extensively review the physiologic basis for the use of ORS, clinical assessment of dehydration, pharmacologic therapy and nutritional issues.

ORS contain specific concentrations of carbohydrate, sodium, potassium, chloride, base (as citrate, acetate or lactate) with a defined osmolarity (240-300 mOsm/L). ORS function to support the coupled transport of sodium and glucose across the bowel wall (intestinal brush border), along with water, into systemic circulation. Systemic absorption of water and electrolytes is maximized when the ratio of carbohydrate to sodium is approximately 1:1.

The CDC guidelines support and recommend the use of ORS for the treatment of mild to moderate dehydration (3%-9% body weight loss). Therapy with ORS entails a biphasic approach: rehydration and maintenance treatment of ongoing fluid loss from diarrhea and/or vomiting. Rehydration therapy includes administering 50 mL/kg to 100 mL/kg in 2 to 4 hours. Additional losses can be replaced with 60 mL to 120 mL of ORS for each diarrhea stool or vomiting occurrence for children weighing less than 10 kg, and 120 mL to 240 mL of ORS for children weighing more than 10 kg.

Technique of administration includes use of frequent and small (5 mL or less) volumes given orally with an appropriate device (eg, oral syringe or teaspoon). Larger amounts may be given as tolerated, although allowing a child to initially drink larger amounts may result in vomiting and abandonment of ORS therapy in the home. Alternatively, ORS can be administered by nasogastric technique and can be effectively accomplished in an emergency department setting. Recommendations discussed in the 2003 CDC guidelines for the treatment of severe dehydration (.9% body weight loss) include the use of IV fluids for rehydration.

Clinical trials

Several controlled trials have demonstrated that the use of ORS is clinically equivalent to using IV fluids to treat mild to moderate dehydration and ongoing fluid loss due to diarrhea and/or vomiting. These trials have shown that ORS given appropriately is clinically equivalent to the use of IV fluid therapy. In a randomized trial in an ED setting, rehydration by ORS given orally or by nasogastric tube was found to be clinically similar to treatment with IV fluids in 104 children aged 3 to 36 months with mild to moderate dehydration from acute gastroenteritis. Only two of 52 children randomly assigned to oral treatment failed therapy (neither received nasogastric treatment), as compared with children receiving no IV therapy.

In a similar but more recently published trial, 34 children (aged 3 months to 17 years) presenting to a pediatric ED with moderate dehydration due to acute gastroenteritis were randomly assigned to treatment with ORS or IV fluids. The primary outcome measure was length of stay in the ED. The mean length of stay in children receiving ORS was 225 minutes compared with 358 minutes for children receiving IV fluid therapy (P<.05). Mean staff was also less in children receiving ORS (36 minutes vs. 65 minutes for children receiving IV therapy; P<.05).

Three children failed ORS and required IV fluid treatment. Two children receiving ORS required hospital admission (11%) compared with four children who received IV therapy (25%, P>.05). More parents of children receiving ORS reported high satisfaction with treatment (77%) compared with parents of children receiving IV therapy (38%, P<.05).

Barriers to use of ORS

If clinical trials have demonstrated the clinical efficacy of ORS for the treatment of mild to moderate dehydration in children, why is ORS not utilized more? Several surveys of pediatric clinicians have shed some light on this. Synder sought to determine how closely 300 pediatricians from various practice settings followed AAP guidelines on the treatment of dehydration. In this survey, the reported usage rate of ORS was less than 30% and did not differ from the use of nonphysiologic fluids such as juices and soda.

Reis surveyed 104 pediatricians on their knowledge, attitudes and practices of ORS therapy. Thirty percent of these pediatricians reported not using ORS for children with moderate dehydration and vomiting, and they said ORS was not indicated or effective. Only 5% of surveyed pediatricians in this survey recommended using an oral syringe or similar device for small, frequent administration of ORS.

Ozuah surveyed 176 ED physicians and compared physicians familiar with AAP guidelines to physicians unfamiliar with these guidelines. ED physicians in this survey reporting to be familiar with AAP guidelines were threefold more likely to use ORS for children with mild to moderate dehydration compared with physicians reporting less familiarity with AAP guidelines. Reasons for not using ORS expressed by clinicians in these and other surveys include a belief that ORS is not effective for children with moderate dehydration, ORS use is too time-consuming, lack of support from staff for using ORS and financial concerns (less reimbursement for ORS therapy).

ORS products

Several ORS products are available, although most pharmacies and grocery stores will likely only have the Pedialyte brand (Abbott Nutrition), which has the major share of the ORS commercial market. Other products that may be listed in published review articles, such as Infalyte (Ricelyte), Rehydralyte or Equalyte, are no longer available.

Pedialyte is available in several dosage forms, including ready-to-drink liquids (unflavored and flavored — cherry, grape, blue, raspberry, orange), powder packs for reconstitution and freezer pops, all in several flavors. Retail prices for Pedialyte products are approximately $6 to $9. Generic-flavored ORS products are also available in many pharmacies and grocery stores and are less expensive than Pedialyte (approximately $4).

Besides Pedialyte (a glucose-based product), a rice-based product available is CeraLyte, as 50-, 70-, and 90-strength products (referring to 50-90 mEq/L sodium) in flavored powder packets for reconstitution and ready-to-drink liquid. CeraLyte is not as readily available in retail pharmacies as other ORS products but is available online and through many hospital outpatient pharmacies. Some evidence exists that rice-based ORS products may have benefit over glucose-based ORS products by decreasing a need for supplemental IV fluid treatment.

WHO also produces ORS products, although these are not readily available to consumers. These ORS packets are available as standard and hypo-osmolar powders for reconstitution, with osmolarities and sodium content of 311 mOsm/L and 245 mOsm/L, and 90 mEq/L and 75 mEq/L, respectively. WHO ORS products are used throughout the world and in developing countries where diarrheal diseases and dehydration more commonly occur. Hypo-osmolar ORS have been shown to result in less vomiting, less stool output, and less need for supplemental IV fluid therapy when used for non-cholera diarrhea.

It is important to note that common beverages should not be used as rehydration solutions for children. Liquid products such as sport drinks (eg, Gatorade) and juices are hyper-osmolar, with osmolarities of 330 mOsm/L to 730 mOsm/L. These hyper-osmolar solutions may worsen diarrhea and fluid loss. Additionally, these fluids do not contain adequate amounts of electrolytes. For example, ORS and sport drinks contain the following concentrations (mmol/L) of sodium, potassium, chloride and base, respectively: 45-90 vs. 23.5; 20 vs. <1; 35-80 vs. 17; and 30 vs. 3.

Pharmacologic therapy

Pharmacologic anti-diarrheal products, such as anti-motility agents or adsorbents, should not be used in children, as few data are available to support their efficacy, and they can cause significant adverse effects. Infant deaths due to ileus formation have been reported from the use of loperamide. Loperamide is available in pharmacies as an over-the-counter pediatric product, Imodium A-D (McNeil Consumer Healthcare), with pediatric bottle labeling advertising for use in ages 6 years and older. Another commonly available product, Pepto-Bismol (Proctor & Gamble), also should not be given to children with viral acute gastroenteritis. Pepto-Bismol contains bismuth subsalicylate and should not be used in children because of the potential for salicylate toxicity or Reye’s syndrome. A pediatric product is also available, Children’s Pepto, which contains calcium carbonate, an antacid and without anti-diarrheal effects.

Edward A. Bell, PharmD, BCPS, is a Professor of Clinical Sciences at Drake University College of Pharmacy, Blank Children’s Hospital and Clinics in Des Moines, Iowa.

For more information:

  • Atherly-John Y. Arch Pediatr Adolesc Med. 2002;156:1240-1243.
  • Fuchs GJ. J Pediatr Gastroenterol Nutr. 2002;34:252-253.
  • Gregorio GV. Cochrane Database Sys Rev. 2009 Apr 15;(2):CD006519.
  • King CK. MMWR. 2003;52:1-16.
  • Mackenzie A. BMJ. 1991;303:393-396.
  • Ozuah PO. Pediatrics. 2002;109:259-261.
  • Reis EC. Pediatrics. 1994;93:708-711.
  • Synder JD. Pediatrics. 1991;87:28-33.