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Every 14 seconds, a child dies of dehydration secondary to diarrhea.¹The problem is not isolated to developing countries: Each year in the United States, diarrhea accounts for 300 deaths, more than 200,000 hospitalizations, and 1.5 million outpatient visits in children younger than 5 years.²This translates into costs exceeding $2 billion per year.²Knowing how to manage pediatric patients who present with diarrhea is key in decreasing the morbidity and mortality associated with diarrhea in American children.

Acute gastroenteritis, a form of diarrheal disease marked by rapid onset, may be accompanied by nausea, vomiting, fever, and abdominal pain.²Most acute gastroenteritis in the pediatric population is infectious and self-limited.

History of oral rehydration therapy

In the 1940s, the use of intravenous fluids (IVF) containing an appropriate balance of sodium, chloride, bicarbonate, and potassium reduced mortality resulting from acute gastroenteritis in hospitalized infants to less than 5%. In 1943, the first oral rehydration solution (ORS), fluids containing specific concentrations of electrolytes, was developed and used to successfully treat patients with dehydration secondary to gastroenteritis in Baltimore City Hospitals in Baltimore, Md. The later development of another ORS by the World Health Organization (WHO) also proved to be an effective remedy to the problem. More readily available and less costly than IVF, ORS came to be widely used in developing countries, and since the 1970s the use of ORS in these nations has resulted in a significant decrease in mortality caused by diarrheal illness. In fact, oral rehydration therapy (ORT), which consists of rehydration, continued feeding of normal diet, and replacement of continuous fluid loss, now saves the lives of more than 1 million children annually.^1,3

Not only is the efficacy of ORS in treating dehydration recognized in developing countries, but the American Academy of Pediatrics (AAP) also has accepted it as the treatment of choice in American children with mild to moderate diarrhea.²Despite this recommendation, many US clinicians still lack confidence in ORS, preferring to use IVF in pediatric patients with dehydration secondary to acute gastroenteritis. In order to ensure that these patients are managed most effectively and to reduce pediatric morbidity and mortality due to diarrheal illness, clinicians must understand ORT and properly assess their pediatric patients with diarrhea.

Anatomy and pathophysiology

Acute gastroenteritis occurs when the absorptive and secretory processes in the small and large bowels are disrupted. Normally these areas of the GI tract absorb 98% of the fluid that passes through them. Since water follows solute, water absorption is made possible by the bowel’s three mechanisms of solute absorption—neutral sodium chloride absorption, electrogenic sodium absorption, and sodium cotransport. In diarrhea due to enteric infection, the sodium cotransport mechanism remains intact, but the electrogenic sodium absorption is disrupted, thereby decreasing water absorption. ORS is effective in treating dehydration secondary to diarrhea because it makes use of the sodium cotransport system and makes available both sodium and glucose that are necessary for this system to transport solute (and ultimately water) across the intestinal wall. Thus, ORS makes rehydration possible by simultaneously replacing fluids as they are being lost through diarrheal infection.^4,5

History and physical exam

The history is significant in determining the etiology of the diarrhea in the pediatric patient presenting with acute gastroenteritis. The clinician should make note of possible causes of acute gastroenteritis such as recent antibiotic use and travel, day-care experiences, or ill family members.⁴Additional risk factors for diarrheal illness include poverty, decreased sanitation, temperate climate, dry conditions, and the onset of cool weather.⁶

Both the history and physical examination are key in assessing the severity of dehydration and deciding on the proper management. The history should determine the composition and amount of fluid intake; the frequency and volume of output through vomiting, diarrhea, and urination; the severity and length of fever; the presence of underlying disease; and the amount of weight loss.⁷The examination will enable further assessment of the severity of dehydration so that the patient can be classified as mildly, moderately, or severely dehydrated (see Table 1*). For example, delayed capillary refill indicates severe dehydration until shown otherwise.²Weight loss, skin changes, hemodynamic indicators, fluid losses, and urine characteristics are other features evaluated for this purpose.⁷

*The last line of the table refers to the concentration of sodium in urine, with <20 mEq/L indicating mild or moderate dehydration.

Assessment and differential diagnosis

Once the degree of dehydration is assessed, children found to be severely dehydrated should begin IVF immediately and be admitted to the hospital as necessary. Those with mild to moderate dehydration can begin ORT, as will be discussed later.

As the rehydration process begins, the clinician should determine whether the gastroenteritis is, in fact, causing the dehydration. Decreased oral consumption when a child is ill, as well as increased fluid requirements during fever, can also produce dehydration. The practitioner should not assume a child is dehydrated solely because he or she has diarrhea; rather, it is important to evaluate intake and fever in addition to output. If diarrhea is causing the dehydration, note the duration; chronic diarrhea, unlike the acute form, has many noninfectious etiologies: antibiotic therapy, malnutrition, disorders such as inflammatory bowel disease and celiac sprue, and genetic and endocrine diseases. The distinction is important because management of chronic diarrhea is more extensive and may require referral to a specialist. If the dehydration is determined to be secondary to acute gastroenteritis, the diarrhea’s etiology is usually viral, although it could be bacterial or parasitic. Clinical and laboratory evaluation will be necessary if the latter two etiologies are suspected. While antimicrobial or antiparasitic medications may be indicated, management of dehydration caused by any of these three etiologies will remain the same.⁷

Laboratory and diagnostic testing

The presenting history and physical examination often enable clinicians to distinguish among likely causes of the diarrhea and thus help in determining the tests that should be ordered. For example, if a mildly dehydrated young child presents in December after 2 days of emesis and watery diarrhea, suspect rotavirus. In this case, no laboratory work is necessary. If a specific etiology must be verified, the virus can be determined from a stool sample. However, if this child were to present with fever as well as diarrhea containing blood and mucus, suspect a bacterial etiology. In this case, evaluation begins with a stool analysis for occult blood, leukocytes, and culture. Finally, if the child has recently traveled to an area with a high prevalence of parasites, stool testing would be indicated.

Electrolyte measurements are not indicated in most patients, regardless of the suspected etiology. Electrolytes should be assessed if a child is moderately dehydrated without the expected course of diarrheal episodes, is severely dehydrated, or is receiving IVF.⁴

Treatment recommendations

In 1996, a subcommittee of the AAP established guidelines for management of acute gastroenteritis in young children living in developed nations.* From its extensive study of ORT, the committee determined that oral rehydration was as effective as IV therapy in correcting dehydration secondary to acute gastroenteritis. It therefore recommended oral rehydration as the treatment of choice for mild to moderate dehydration and IV therapy as the treatment for severe dehydration.²The committee advised specific management of patients with diarrheal illness based upon the severity of their dehydration (see Table 2).

*The guidelines are specific to children 1 month to 5 years of age who live in developed countries and have no previously diagnosed disorders. The guidelines are not to be extended to children with diarrhea persisting longer than 10 days, diarrhea in addition to failure to thrive, or vomiting without diarrhea.

Besides the committee’s recommendations concerning ORT, the practice parameter gave other suggestions for children with acute gastroenteritis. For example, the committee discouraged the replacement of ORS with fluids containing nonphysiologic concentrations of glucose and other electrolytes, such as soft drinks, apple juice, chicken broth, and sports drinks. The hypo-osmolar solutions, such as Pedialyte, have no significant additional benefit over standard (higher osmolality) ORS. Additionally, the committee recommended beginning age-appropriate feeding as soon as the dehydration resolved; examples include breast milk for infants and a balance of complex carbohydrates, lean meats, fruits, vegetables, milk, and yogurt in older children. High-fat foods, highsugar drinks, and lownutritive diets (such as the BRAT diet of bananas, rice, applesauce, and toast) were discouraged. The committee also noted that medications (including loperamide, opioids, anticholinergics, and bismuth subsalicylate) usually are not indicated in acute gastroenteritis. In addition, it found that patients who refuse ORS are usually not sufficiently dehydrated for ORS to be indicated.²

Barriers to treatment recommendations

Despite these findings and recommendations, many clinicians do not manage acute gastroenteritis and dehydration according to the guidelines of the AAP. In one survey, fellowship-training directors in pediatric emergency medicine noted their recommendations in 10 hypothetical scenarios of mild or moderate dehydration secondary to gastroenteritis. While appropriate management was ORT in all scenarios, only 17.2% of the directors surveyed believed ORT was best in every case and only 6.7% actually said they would use ORT in all scenarios.⁸

Another survey of primary care clinicians had similar results. In this survey’s set of clinical scenarios, children had diarrhea and vomiting but could still consume oral fluids and did not require hospital admission. Although the appropriate management in all three scenarios was to begin ORS followed by early refeeding of a normal diet, a number of general practitioners recommended inappropriate treatments including stopping the normal diet, starving the child, and using inappropriate fluids (such as flat cola or juice).⁹

These surveys demonstrate that ORT is not universal practice in the United States. Clinicians cite several barriers to its acceptance: fear of iatrogenic hypernatremia, perception that vomiting contraindicates ORS, patients refusing ORS, decreased parental satisfaction with ORS as compared to IVF, increased staff time required to administer ORS as compared to IVF, increased expense to families, and belief that ORS is simply not as effective as IVF in treating dehydration secondary to acute gastroenteritis.^3,4How many of these barriers are justified?

Iatrogenic hypernatremia In the 1950s, clinicians became wary of using ORT because of the iatrogenic hypernatremia associated with early ORS. At that time the dry ingredients of the commercial packets often were added to inappropriate volumes of water, resulting in hypernatremia. Commercially distributed highcarbohydrate solutions led to the same problem, and clinicians became reluctant to use ORT.³

However, in the 1960s WHO developed an ORS with specific concentrations of sodium, chloride, bicarbonate, potassium, and glucose. The solution was shown to be both safe and effective in treating dehydration.³A more recent study showed that pediatric patients on ORS are at no greater risk for developing iatrogenic hypernatremia or hyponatremia than are those on IVF. In fact, the study determined that all OTC solutions available in this country were appropriate and efficacious in rehydrating wellnourished children. These solutions contained 45 to 70 mEq/L sodium, carbohydrate-to-sodium ratios of less than 3, and osmolalities of 235 to 310.¹⁰Table 3 offers a current list of ORS products available in the United States. With the reformulation of ORS over the past several years, iatrogenic hypernatremia should no longer be a barrier to its use in this country.

Vomiting Another barrier to ORS use is the belief that vomiting is a contraindication to its administration. In reality, however, ORS often leads to decreased emesis as well as faster rehydration than with IVF use. Thus the AAP suggests giving 1 tsp (5 mL) of ORS every 1 or 2 minutes to dehydrated vomiting patients. As vomiting decreases, one can administer increased volumes of ORS. If vomiting is not reduced with these measures, then IVF is appropriate.²

Patient refusal Many clinicians maintain that children do not like the taste of ORS and refuse it. In one survey, 40% of American pediatricians found this to be a barrier to ORS use.¹¹However, the AAP states that children who refuse ORS usually are only slightly dehydrated, if at all, and these children can continue regular diets without ORS.²Dehydrated children, however, usually crave the salt and water ORS provides; they are the children for whom ORT is indicated.³

If a child does refuse ORS and is dehydrated, clinicians or families may offer small volumes of ORS until the child adapts to the taste. Or they may try flavored ORS or ORS popsicles, which may be more acceptable to the dehydrated child.²

Parental dissatisfaction A recent study comparing oral versus IV rehydration in an urban pediatric emergency department (ED) evaluated the validity of many other perceived barriers to ORS. The study found that parents were significantly more satisfied with ORT than with IVF (77% versus 37.5%, P=.01).¹²

Increased staff time In this study the parents administered the ORS.¹²With this approach, instead of finding that hospital staff time was increased with ORT over IVF, the study found mean staff time to be significantly less with ORS than with IVF (35.8 minutes versus 65 minutes, P=.03).

Increased family expense Rather than finding that ORT increased the expense to families, the study found that ORS, as compared to IVF, significantly decreased the length of stay in the ED (P<.01) and did not significantly increase the rate of hospital admissions (P=.20).¹²Both results decreased costs for families. An earlier study published also confirmed the decreased costs of outpatient ORT given in the ED ($272.78) over both outpatient ($379.20) and inpatient ($2,299.50) IV treatment.¹³

Effectiveness of ORT Many clinicians still believe that ORT is less effective than IV rehydration. Does the evidence support this belief? A meta-analysis of studies from developed nations of well-nourished children with mild to moderate dehydration secondary to gastroenteritis examined the efficacy and safety of ORT as opposed to IV rehydration.¹⁰The study found an ORT failure rate of 3.6%, which was not significantly different from failure rates of IV rehydration. In fact, the meta-analysis concluded that patients treated with ORS had a decreased duration of diarrhea, a larger weight gain at hospital discharge, and a shorter hospital stay.

The findings of all of these studies on ORT support the AAP’s recommendation of ORT as the preferred and most efficacious treatment of mild to moderate dehydration in children with acute gastroenteritis.

Contraindications to ORT

ORT is contraindicated in infants with volume losses greater than 10%. It is also contraindicated in children with an inability to drink fluids (possibly because of impaired consciousness or respiration), with suspected acute surgical abdomen, with hemodynamic instability, or with severe sodium imbalances (outside the range of 120160 mEq/L). If ORT has failed because of vomiting or the solution’s inability to replenish losses, IVF should replace ORS.⁷

Indications for IVF

IV rehydration is recommended in children with severe dehydration who are either near or in a state of shock, and in children who are moderately dehydrated but are unable to retain ORS because of constant emesis. It is also indicated in unconscious patients and those with ileus. In addition, if no one is available to administer ORT as required, IVF is recommended as first-line treatment.²

Prevention and education

Education and preventive care will keep many severe situations from occurring. Clinicians should identify patients most at risk for acute gastroenteritis. They must educate the parents, especially those whose children are high risk, about the importance of preventing diarrheal illness with such sanitation measures as hand washing and explain the progression of the condition. Practitioners should educate parents on how to appropriately manage their children should diarrhea occur and how to recognize the signs and symptoms of dehydration.²A survey of American mothers concluded that while most knew the potential seriousness of diarrhea, many used inappropriate methods of managing their children’s problems.

Oral rehydration therapy in children with acute gastroenteritis

Oral rehydration therapy—it’s the treatment of choice for dehydration in young children with diarrhea. Which type works best? Why is ORT so effective? How can you administer it to your patients?

Molly Ulrickson, PA-C

Ms. Ulrickson is a family practice physician assistant with the John Deere Medical Group, Waterloo, Iowa. The author has indicated no relationships to disclose relating to the content of this article.

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