Pediatric Oral Rehydration

Full update December 2016

Introduction

In children, dehydration due to diarrhea or vomiting from gastroenteritis is a common clinical situation. Early treatment with oral rehydration therapy can prevent worsening dehydration; office, clinic, and emergency department visits; and possibly hospitalizations and deaths. Commercially available electrolyte solutions (e.g., Pedialyte, etc) may be expensive, poorly tolerated, and not immediately or readily available to parents.¹ This leads to questions about other options for rehydration, such as fruit juice, sports drinks, etc. This article will review dehydration in children and its appropriate treatment.

Dehydration in Kids

Dehydration results when a child does not take in enough fluid or they have an increase in fluid losses (e.g., from vomiting or diarrhea).² In the U.S. and Canada dehydration accounts for a significant number of pediatric outpatient visits, hospitalizations, and occasional deaths.³

In children, the most common cause of dehydration is diarrhea from gastroenteritis. Very young children and infants are at an increased risk for dehydration due to a higher metabolic rate which increases fluid requirements, a higher rate of loss from evaporation (i.e., sweat) because of a greater surface area to volume, and their decreased ability to communicate that they are thirsty or to get themselves a drink.²

The following Clinical Dehydration Scale can be used to assess a child’s level of hydration:⁴

Patients receive a score of zero to eight which categorizes their hydration:

0: no dehydration
1 to 4: some dehydration
5 to 8: moderate to severe dehydration

In addition to the clinical signs assessed in the scale above, the loss of body weight is also used to help categorize dehydration.⁵ Dehydration is defined as mild when there is less than 5% loss of total body weight, moderate with a loss of 5% to 10%, and severe with more than 10% loss.⁵ Patients should be weighed on presentation in order to have a baseline hydration measure.

Electrolytes are in all fluids of the body, so vomiting and diarrhea always result in the loss of some amount of electrolytes.² Children with mild dehydration often have normal electrolyte values. Lab testing is usually reserved for patients with severe dehydration when intravenous fluid rehydration is being used.⁶

The World Health Organization, American Academy of Pediatrics, and Canadian Paediatric Society all recommend oral rehydration therapy for mild and moderate dehydration.^2,7

Oral Rehydration Therapy

Managing dehydration in children must include correction of any dehydration, replacement of ongoing fluid losses, as well as maintenance of adequate electrolytes and carbohydrates.^5,8

Oral rehydration therapy (ORT) with a glucose and electrolyte solution has been shown to be a safe, practical, and highly effective treatment for dehydration in both developing and developed countries.⁷ The glucose in these solutions provides calories and helps to increase the absorption of sodium, and therefore water. The recommended glucose to sodium ratio is 1:1.⁷ The osmolality of these solutions is also important to ensure optimal absorption of fluid. Hyperosmolar solutions may increase the risk for hypernatremia or increase stool output with osmotic diarrhea.¹⁰ Different organizations recommend slightly different concentrations and osmolalities for oral replacement fluids.⁷ The current recommendations from the World Health Organization are 75 mmol/L of sodium and an osmolality of 245 mOsm/L.⁸

Commercially Available Hydration Solutions

There are many different commercially available oral electrolyte solutions (Pedialyte, Enfalyte, Equalyte, Oralyte, etc). These solutions contain electrolytes (i.e., sodium, potassium, and chloride) as well as carbohydrates (e.g., dextrose, corn syrup, etc). They are available in a variety of flavors, sizes, and formulations (e.g., solution, powders, freezer pops, etc). There are also formulations available that contain prebiotics (Pedialyte Advanced Care), promoted for rehydration plus digestive health.

Be cautious of electrolyte replacements that are not formulated with fluid. For example, Solves Strips Pediatric Electrolyte are dissolvable strips that each have 15 mg of sodium and 20 mg of potassium but no carbohydrates/sugar.⁹ Nuun Active tablets are an electrolyte replacement described as a “sports drink.” These products are generally not recommended for the treatment of dehydration in children because they do not replace fluids. Patients must still have adequate intake of water or other fluids when taking these electrolyte replacements.

Give parents clear instructions when purchasing rehydration products. They should not add water to the ready-to-use formulations. These products contain a balanced amount of electrolytes and carbohydrates and are designed to maintain fluid and electrolyte balance in infants and children who have excessive losses (i.e., from diarrhea or vomiting).

Powders must be mixed precisely to ensure intended electrolyte concentrations and osmolality. Powders may be easier for parents to store and keep on hand, generally have a longer shelf-life, and may be less expensive. But, premixed solutions are recommended over powders or homemade solutions due to the potential for dilution errors.⁵

Homemade Hydration Fluids

If commercially available oral electrolyte solutions are not available, parents can be instructed on making oral electrolyte solutions at home. However, these solutions should only be used temporarily while patients are seeking commercial solutions or medical attention. It is important for parents to understand that errors in making the solution can lead to serious adverse effects. A solution with a little extra water may not be harmful, but using too much salt can worsen diarrhea or may cause hypernatremia. While there are a number of published formulations, one of the more common formulations recommended by the Rehydration Project (www.rehydrate.org) is:¹¹

• 2.5 mL (1/2 teaspoon)* of salt
• 30 mL (2 tablespoons)* of sugar (artificial sweeteners should NOT be used as they may increase diarrhea and will not provide sufficient carbohydrates).
  *(using measuring spoons to improve accuracy)
• One liter of clean drinking or boiled water

Stir the mixture until the salt and sugar dissolve. Store the liquid in a cool place and discard after 24 hours. Chilling the oral rehydration solution may help mask the taste.¹¹

Alternative Fluids

Oral rehydration solutions can be expensive, unavailable, and have an unpleasant taste. These limitations may prevent children from receiving the needed fluid. This can lead to worsening dehydration and potentially increased visits to their prescriber or emergency room, hospital admissions, and the need for intravenous rehydration.¹

Sports drinks (e.g., Gatorade, etc) should not be used in place of oral rehydration solutions as these solutions contain a lot of sugar and low levels of electrolytes.

Guidelines do not recommend other fluids such as soft drinks, juices, soups, and broths for the correction of dehydration as these also do not have adequate and balanced electrolyte and glucose concentrations. High sugar-containing soft drinks, carbonated drinks, sweetened fruit juice, etc, are discouraged due to their high osmolality. Hyperosmolar solutions can cause osmotic diarrhea when they are ingested in large quantities. Also keep in mind that giving water alone to a child with acute gastroenteritis and dehydration could lead to hyponatremia and hypoglycemia.^5,7

Due to the limitations described above for oral rehydration solutions, a new study compared rehydration with Pedialyte electrolyte solution to half-strength apple juice, followed by preferred liquids (milk, sports drinks, high-sugar content drinks, etc) at home, in children with mild gastroenteritis and minimal dehydration (Clinical Dehydration Scale (CDS) score of less than 5). Children received their assigned rehydration (Pedialyte or diluted apple juice) in the emergency department. On discharge, the apple juice group was instructed to replace vomiting or diarrhea losses with diluted apple juice or, less preferably, with their child’s usual drink, which could be milk, juice, water, sports drinks, etc. The Pedialyte group was instructed to continue to replace losses at home with Pedialyte. In this study, 68.2% of the children randomized did not have clinical evidence of dehydration (i.e., CDS score of 0), 13.6% had a CDS score of 1, 11.9% had a CDS score of 2, and 3.3% had a CDS score of 3, and 3.1% (i.e., 20 patients) had a CDS score of 4. The 644 children included in the study were six months to 60 months old, presenting to the emergency department. Patients in the diluted apple juice group were found to have less treatment failures than those in the Pedialyte group (54 patients [16.7%; 95% CI 12.8 to 21.2] versus 81 patients [25%; 95% CI 20.4 to 30.1] respectively, p<0.001 for inferiority and p=0.006 for superiority). The absolute risk reduction (ARR) was 8.3% and the number needed to treat (NNT) = 12 (i.e., twelve patients would need to be treated with diluted apple juice to prevent one treatment failure). Treatment failure was defined as one of these events within seven days of enrollment into the study: requiring IV rehydration; hospitalization subsequent office, clinic, or emergency room visit; having at least three episodes of vomiting or diarrhea within a
24-hour period; physician request to crossover treatment groups; 3% or more weight loss; or CDS score of 5 or more on follow-up.¹ Of note, the only defined treatment failure that was statistically significant was a decrease in patients requiring IV rehydration (eight vs 29, absolute risk reduction of 6.5%, p=0.001) in the juice group vs the Pedialyte group, respectively.

Volume for Rehydration

The amount of rehydration that is needed depends on the size of the individual and the degree of dehydration. In general, 50 mL/kg is required for mild dehydration while 100 mL/kg may be needed for moderate dehydration. Rehydration should be given slowly over three to four hours.⁵

Ongoing losses (e.g., if the child continues to have diarrhea and/or vomiting) should also be considered and replaced. For children weighing less than 10 kg (or under the age of two years), give 60 to 120 mL of an oral rehydration solution for each episode of vomiting or diarrhea. For children weighing more than 10 kg (or over the age of two years), 120 to 240 mL of solution should be administered for each episode of vomiting or diarrhea.⁵ In hospital, amounts can be more specific as outputs can be measured when necessary. One mL of fluid is recommended for replacement of each gram of output. Stool volumes can be determined in infants by weighing soiled diapers and subtracting the estimated dry weight of the diaper.⁸

A teaspoon, syringe, or medicine dropper can be used to give small amounts of fluid (e.g., one teaspoon or 5 mL). Amounts should gradually be increased, as tolerated.⁵ After three to four hours, the child’s hydration status should be reassessed. If the patient is rehydrated, an age-appropriate diet can be started. If the patient is still dehydrated, the fluid deficit should be recalculated and rehydration therapy should begin again.⁸

An age-appropriate, unrestricted diet can be started as soon as dehydration is corrected. This has been shown to improve clinical and nutritional status. Parents may find some foods are initially better tolerated, for example, starches, cereals, yogurt, fruits, and vegetables.⁵

Breastfeeding should continue throughout the course of the illness and rehydration therapy.^5,8

When to Refer

Although oral rehydration solutions are effective and safe in infants and children with mild to moderate dehydration, it is important to know when a child should be referred to their prescriber. A child with a Clinical Dehydration Scale score of five or more (i.e., moderate to severe dehydration) should be referred. Children with severe dehydration will usually need to be treated initially with intravenous fluids, followed by oral rehydration once they are stable.⁷

Regardless of a child’s Clinical Dehydration Scale score, caregivers should be instructed to contact their prescriber for:⁵

• infants less than six months or 8 kg
  (18 pounds)
• concurrent illness, history of chronic medical conditions, or prematurity
• visible blood in stool
• fever of 38^OC (100.4^OF) or greater for children less than three months
• fever of 39^OC (102.2^OF) or greater for children three months and older
• frequent, high volume stools
• persistent vomiting
• symptoms of more severe dehydration such as sunken eyes, decreased urine output, dry mucous membranes, decreased tears
• changes in mental status, such as irritability, apathy, or lethargy
• lack of response or inability to take oral rehydration solutions

Conclusion

Oral rehydration solutions are preferred for the prevention and treatment of dehydration in children. However, if there are limitations preventing their administration in children who are at least six months old with mild gastroenteritis, mild dehydration, and a Clinical Dehydration Scale score of four or less, half-strength apple juice may be a reasonable alternative for the prevention of progression to clinical dehydration [Evidence Level A; high-quality RCT].¹

Levels of Evidence

In accordance with the trend towards Evidence-Based Medicine, we are citing the LEVEL OF EVIDENCE for the statements we publish.

Adapted from Siwek J, et al. How to write an evidence-based clinical review article. Am Fam Physician 2002;65:251-8.

Project Leader in preparation of this clinical resource (330109): Annette Murray, BScPharm

References

1. Freedman SB, Willan AR, Boutis K, Schuh S. Effect of dilute apple juice and preferred fluids vs electrolyte maintenance solution on treatment failure among children with mild gastroenteritis: a randomized clinical trial. JAMA 2016;315:1966-74.
2. Cellucci MF. Dehydration in Children. November 2014. http://www.merckmanuals.com/professional/pediatrics/dehydration-and-fluid-therapy-in-children/dehydration-in-children. (Accessed June 6, 2016).
3. Schnadower D, Tarr PI, Gorelick MH, et al. Validation of the modified Vesikari score in children with gastroenteritis in 5 U.S. emergency departments. J Pediatr Gastroenterol Nutr 2013;57:514-9.
4. Friedman JN, Goldman RD, Srivastava R, Parkin PC. Development of a clinical dehydration scale for use in children between 1 and 36 months of age. J Pediatr 2004:145:201-7.
5. CDC. Guidelines for the management of acute diarrhea after a disaster. July 2014. https://www.cdc.gov/disasters/disease/diarrheaguidelines.html. (Accessed June 7, 2016).
6. Somers MJ. Clinical assessment and diagnosis of hypovolemia (dehydration) in children. Last updated April 2015. In UpToDate, Post TW (ed), UpToDate, Waltham, MA 02013.
7. Canadian Paediatric Society. Oral rehydration therapy and early refeeding in the management of childhood gastroenteritis. February 2016. http://www.cps.ca/documents/position/oral-rehydration-therapy. (Accessed June 7, 2016).
8. King CK, Glass R, Bresee JJ, et al. Managing acute gastroenteritis among children: oral rehydration, maintenance, and nutritional therapy. MMWR Recomm Rep 2003;52(No. RR-16):1-16.
9. Anon. Solves Strips Pediatric Electrolyte information sheet. https://www.solvesstrips.com/pages/solves-strips-pediatric-electrolyte-information-sheet. (Accessed June 9, 2016).
10. Rehydration Project. Expert consultation on oral rehydration salts (ORS) formulation. April 2014. http://rehydrate.org/ors/expert-consultation.html. (Accessed June 10, 2016).
11. Rehydration Project. Oral Rehydration Solutions: Made at Home. July 2014. http://rehydrate.org/solutions/homemade.htm. (Accessed June 8, 2016).

Cite this document as follows: Clinical Resource, Pediatric Oral Rehydration. Pharmacist’s Letter/Prescriber’s Letter. January 2017.

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