Approach Considerations
Address emergent airway, breathing, and circulatory problems first. Obtain intravenous access, and give a 20 mL/kg isotonic fluid bolus (Ringer lactate or normal saline) to children with severe volume depletion. This should not delay transport to the appropriate facility. Reassessment of perfusion, cardiac function, mentation should take place after each intervention. At times, cardiac failure can mimic volume depletion leading to further deterioration of clinical findings after fluid administration.
Failure to diagnose appendicitis, intussusception, or small bowel obstruction places patients at risk of serious complications (including death).
Antidiarrheal medications have adverse effects and are generally not recommended without medical supervision.
Mild Volume Depletion
Patients with minimal to mild volume depletion should be encouraged to continue an age-appropriate diet and adequate intake of oral fluids. Oral rehydration solution (ORS) should be used. Children should be given sips of ORS (5 mL or 1 teaspoon) every 2 minutes. [11] As an estimate for the amount of fluid to replace, the goal should be to drink 10 mL/kg body weight for each watery stool and estimate volume of emesis for each episode of vomiting. [5, 11, 21]
If commercially prepared ORS is not available, the following recipe may be used:
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In 1 L of water, add 2 level tablespoons of sugar or honey, a quarter teaspoon of table salt (NaCl), and a quarter teaspoon of baking soda (bicarbonate of soda)
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If baking soda is not available, use another quarter teaspoon of salt instead
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If available, add one-half cup of orange juice, coconut water, or a mashed ripe banana to the drink
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Use a safe water source, boil water if source is questioned
Inpatient therapy generally is not indicated for mild volume depletion. However, it is prudent to arrange outpatient follow-up evaluation within 48 hours, with instructions to return sooner if symptoms worsen.
Guidelines from the American Academy of Pediatrics on fruit juice in infants, children and adolescents recommend against the use of fruit juice in the treatment of dehydration or the management of diarrhea. [13]
A study by Freedman et al indicated that in children with mild gastroenteritis and minimal dehydration, better oral rehydration results can be achieved by substituting dilute apple juice (initially) and a preferred fluid (later) for electrolyte maintenance solution. [14]
Moderate Volume Depletion
The literature supports use of oral rehydration for the moderately dehydrated child. Similar outcomes have been achieved in randomized studies comparing ORS with intravenous fluid therapy with fewer complications and higher parent satisfaction in the ORS groups. Moreover, ORS can typically be initiated sooner than IV fluid therapy. However, children must be cooperative and have caregivers available to instruct and administer the oral fluids. [11]
With ORS, patients should receive approximately 50-100 mL/kg body weight over 2-4 hours, again starting with 5 mL every 5 minutes. [5] If the child can tolerate this amount and asks for more fluids, the amount given can gradually be increased. Once the fluid deficit has been corrected, parents should be instructed on how to replace volume losses at home if the child continues to have vomiting or diarrhea.
Children in whom ORS fails should be given a bolus (20 mL/kg) of isotonic fluid intravenously. This may be followed by 1.5-2 times maintenance therapy. Over the next few hours, the patient may be transitioned to oral rehydration as tolerated, at which point the intravenous therapy may be discontinued.
Children with moderate volume depletion may require inpatient treatment if they are unable to tolerate oral fluids despite rehydration. Hospitalization may also be required for treatment of the underlying cause of the fluid deficit.
Severe Volume Depletion
Patients with severe volume depletion should receive intravenous isotonic fluid boluses (20-60 mL/kg). [5] In children with difficult peripheral access, perform intraosseous or central access promptly. Fluid boluses should be repeated until vital signs, perfusion, and capillary refill have normalized.
If a patient reaches 60-80 mL/kg in isotonic crystalloid boluses and is not significantly improved, consider other causes of shock (eg, sepsis, hemorrhage, cardiac disease). In addition, consider administering vasopressors and instituting advanced monitoring, such as a bladder catheter, central venous pressure, and measuring mixed venous oxygen saturation.
Although physicians typically give normal saline for these initial boluses, it is important to remember to check a bedside glucose level for patients who appear lethargic or altered. Treat hypoglycemia promptly. The appropriate dose is 0.25 g/kg IV (2.5 mL/kg of 10% dextrose or 1 mL/kg of 25% dextrose) with reassessment of glucose level after administration of dextrose.
Once vital sign abnormalities are corrected, initiate maintenance fluid therapy plus additional fluid to make up for any continued losses. Daily requirements for maintenance fluids can be approximated as follows:
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If the patient weighs less than 10 kg, give 100 mL/kg/d
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If the patient weighs less than 20 kg, give 1000 mL/d plus 50 mL/kg/d for each kilogram between 10 and 20 kg
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If the patient weighs more than 20 kg, give 1500 mL/d, plus 20 mL/kg/d for each kilogram over 20 kg
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Divide the total by 24 to obtain the hourly rate
Daily fluid requirements may be met using dextrose 5% in half-normal saline solution. For patients with significant hyponatremia or hypernatremia, it is preferable to use dextrose 5% in normal saline. Dextrose is important to include because these patients generally have a notable ketosis.
The emergency physician also should consider daily sodium and potassium requirements as follows:
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Sodium 2-3 mEq/kg/d
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Potassium 2-3 mEq/kg/d
Isonatremic and hyponatremic volume depletion states may be treated with normal saline or other isotonic solutions. The goal for correction rates for either hyponatremic or hypernatremic patients should be no more than 0.5 mEq/L/h or no more than 8mEq/L per 24 hour period to prevent the devastating CNS complications of over-rapid correction (central pontine myelinolysis and cerebral edema). Full correction of severe sodium abnormalities usually should be staged over 24-48 hours or longer. [2]
Although a potassium deficit is present in all cases of volume depletion, it is not usually clinically significant; few patients with moderate dehydration require supplemental potassium. However, failure to correct for hypokalemia during volume repletion may result in clinically significant hypokalemia.
Add potassium to fluids when the patient has documented hypokalemia. For all other patients, avoid adding potassium to fluids until the patient has received resuscitation and has demonstrated adequate urine output.
Children with severe volume depletion, especially those with hypernatremia or hyponatremia, require inpatient therapy. Children with severe hyperosmolar states, severe electrolyte derangements, or associated renal failure may require admission to a critical care unit.
Pharmacologic Therapy
The emergency medicine literature now supports the use of a single dose of oral ondansetron in combination with oral rehydration for patients with dehydration, nausea, and vomiting. [12, 15, 16] However, the use of an antiemetic should not shift the focus away from adequate fluid resuscitation.
Acute gastroenteritis is typically a self-limited condition that does not require antibiotics. [17] Chronic infectious cases of diarrhea may require antimicrobial agents after appropriate stool studies have indicated the etiology. [18] Antidiarrheal agents are not recommended. When dehydration is caused by other disease processes, such as diabetic ketoacidosis or sepsis, appropriate pharmacologic therapy should be initiated as soon as possible.
Consultations
Infants and children who present to the ED with mild to moderate dehydration may respond to fluid boluses and may be discharged home with close follow-up with their primary care provider. Patients who are severely volume depleted or who are unable to tolerate oral fluids must be admitted, with a pediatric consultation.
If the child is in shock, is unable to drink fluids, or does not respond to intravenous bolus therapy, significant abnormalities requiring correction may exist. In such patients, obtain pediatric consultation for admission and further therapy. If renal tubular acidosis or other primary renal or endocrine disorder is suspected, specialty consultation may be indicated.