Dehydration in pediatrics: learning the treatment once and for all


Acute dehydration mainly affects children under 5 years of age. In Brazil, it was the main cause of mortality in children in past decades, with gastrointestinal losses due to acute diarrhea as the main etiology. However, with the improvement of sanitary conditions, the introduction of oral hydration and vaccination against rotavirus, there has been an exponential improvement in this scenario in the country.

To classify dehydration, the intensity of fluid and electrolyte loss is considered . This can be mild (up to 5% fluid losses), moderate (up to 10% fluid losses), or severe (greater than 10% of body weight). 

Furthermore, it is also possible to classify dehydration according to the amount of serum sodium in hypertonic, hypotonic or isotonic. Isotonic is the most common type , in which sodium and water losses are equal, and serum sodium varies between 130 and 150 mEq/L.

Clinical condition

Mild dehydration

Symptoms are mild or absent. Capillary refill is less than 3 seconds, there is thirst and reduced diuresis with concentrated urine. 

Moderate dehydration 

Thirst is intense, the mucous membranes are dry and there is tachycardia. Capillary refill varies between 3 and 5 seconds.

severe dehydration

The thirst is intense. Hemodynamic changes are even more pronounced, and are often associated with decreased tissue perfusion. Capillary refill lasts more than 5 seconds and the extremities are cool, with fast, thin pulses. 

The hypotension is a late signal , and may be present neurological signs such as lethargy, irritability and coma. It is through these signs that it is possible to diagnose the dehydrated patient and start the most appropriate treatment.

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SURCE Intensive

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To carry out the treatment, the child is offered fluids and electrolytes . It is divided into planes A, B and C, according to the severity of the child’s dehydration. Depending on the case, serum is offered with a solution containing 90 mmol/L of sodium, and homemade solutions, despite being widely spread, should only be offered when there is no such serum. 

Plan A

It is done at home, in children without clinical signs of dehydration . It consists of increasing the supply of fluids and offering oral rehydration serum (ORS) according to the patient’s acceptance, after each evacuation or vomiting. The amount of fluid for each age group is shown in the table below.

50 to 100 ml100 to 200 mlWhen the child accepts

Table of the amount of fluid that should be offered for each age group in oral rehydration therapy (ORT). 

If the patient presents alarm signs , which must be explained to the parents, he/she must return to the health unit. These include decreased diuresis, refusal to eat or worsening of diarrhea. Or, excessive thirst , repeated vomiting and blood in the stool .

Plan B or repair phase

Treatment performed in children with mild to moderate dehydration . The patient must be under in-hospital observation to receive 50 to 100 mL/kg of ORS for 4 to 6 hours . During this period, the diet child should be suspended, however, the breastfeeding should be kept . 

It is not necessary to know her previous weight. However, from the beginning of rehydration, the patient should be weighed for evaluation of oral hydration, which should be done every hour. 

It is necessary to observe if the signs of hydration disappear, if there is an increase in weight and the presence of diuresis. If there is improvement in the clinical picture, return to plan A. However, if there is no improvement, gastroclisis (introduction of a nasogastric tube) is indicated.

Plan C

Indicated for patients with severe dehydration or when the oral route is unfeasible . In this case, when the child has an altered state of consciousness, paralytic ileus, seizures and acute abdomen. 

For those who are part of this plan, the serum needs to be administered parenterally . In addition, the Ministry of Health states that the child does not need to be hospitalized , should only remain under observation for at least 6 hours, and may be discharged when he manages to perform oral hydration. 

Finally, it is recommended by the Ministry of Health that the treatment carried out in the plan be divided into two phases: rapid expansion, and maintenance and replacement. As you can see in the table below.  

Less than 5 years old: 20mL/kg of saline solution every 30 minutes. Repeat until child is hydrated.For any age: 5% glucose serum + 0.9% saline solution in a 4:1 ratio.

Up to 10Kg: 100mL/Kg

Weight between 10 and 20Kg: 1000mL + 50mL/Kg of weight that exceeds 10Kg

Weight over 20Kg : 1500mL + 20mL/Kg of weight that exceeds 20Kg
Over 5 years: 30mL/Kg of saline solution in 30 minutes + 70 mL of Ringer Lactate in 2 hours and 30 minutes.Replacement phase: 5% glucose saline + 0.9% saline in equal parts (1:1). Start with 50mL/kg/day. Reassess for evacuation or vomiting losses.

10% KCl in 2mL for every 100mL of maintenance phase solution

Therefore, it is possible to see that understanding how to identify and treat pediatric patients with dehydration makes all the difference in their prognosis. This is because, despite the introduction of oral hydration and vaccination against rotavirus, it can still lead to death.

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