Heatstroke in a child

Heat stroke in a child is a condition that develops as a result of a pronounced disruption of heat transfer processes caused by unfavorable environmental conditions (high temperature and humidity) and is characterized by an extreme degree of overheating of the body with disruption of the functions of the central nervous system, cardiovascular system and pronounced water-electrolyte disorders.

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Epidemiology of heat stroke in children

Children with CNS diseases, as well as those who have suffered a traumatic brain injury, endocrine system pathology and other conditions characterized by a disruption of thermoregulation mechanisms, are more susceptible to heat stroke.

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How does heat stroke develop in children?

Depending on the development mechanism, several pathogenetic forms of heat stroke are distinguished.

Pathogenetic variants of heat stroke:

• The water-deficient variant develops when the child does not receive enough fluid.
• The hyponatremic variant occurs when a profusely sweating child receives a sufficient amount of fresh water in conditions of alimentary salt deficiency. Signs of CNS damage are caused by increasing hypotonic cerebral edema.

Hyperthermia leads to dysfunction of all organs and systems. There is a decrease in cardiac output, tachycardia and hypotension develop, tissue perfusion decreases sharply. Hypovolemia, a decrease in circulating blood volume and kidney damage lead to the development of oliguria or anuria and acute tubular necrosis. Kidney damage can be aggravated by developing acute rhabdomyolysis.

Symptoms of heat stroke in a child

The clinical picture depends on the pathogenetic variant of heat stroke.

Water-deficit variant of heat stroke

The clinical picture is dominated by intense thirst. The child becomes lethargic, and in some cases delirium and hallucinations occur.

Hyponatremic variant of heat stroke

An early clinical sign of this form of the disease is painful spasms of the muscles of the limbs. There is no thirst. Later, the child becomes restless, excitable, complains of headaches, nausea and vomiting may occur. Later, depression of consciousness develops (up to coma), there is a risk of depression of breathing and cardiovascular system activity.

Differential diagnostic measures

Diagnosis of heat stroke in a child is usually not difficult. However, given that a serious condition may not develop immediately, but 4-6 hours after the child has been in unfavorable conditions, it is necessary to collect anamnestic data. The duration of the temperature increase, fluid intake, diuresis, the presence of predisposing factors and concomitant diseases are determined.

During the initial examination of the patient, it is necessary to first assess the level of consciousness, the effectiveness of spontaneous breathing and hemodynamic parameters. Any disturbances of vital functions are indications for urgent hospitalization of the child in the intensive care unit.

Water-deficit variant of heat stroke

Sweating and diuresis are reduced, mucous membranes are dry. Body temperature rises rapidly. This form of heat stroke is characterized by tremors of the extremities, and in the later period, convulsions may occur.

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Hyponatremic variant

Sweating is not impaired, and body temperature may be slightly elevated.

Treatment of heat stroke in children

When the body temperature is elevated, physical cooling methods are used (the child is undressed, ice packs are applied to the head, neck, and groin area, the skin is moistened and blown with a fan).

Water-deficit heat stroke

If the patient is conscious, give him plenty of lightly salted fluids. Infusion therapy is carried out in the mode of treating hypertonic dehydration.

Basic principles of treatment:

• The initial infusion includes predominantly isotonic or hypotonic saline solutions.
• Considering that plasma osmolarity is sharply increased with this mechanism of heat stroke, the administration of colloidal solutions should be avoided.
• It is necessary to refrain from administering glucose solutions until the blood plasma glucose level is normalized.
• The total infusion volume can be 50-60 ml/(kg x day) and higher.
• In case of seizures, anticonvulsant therapy is prescribed, preferably benzodiazepines.

Hyponatremic heat stroke

In case of isolated sodium deficiency, infusion of 0.9% and hypertonic sodium chloride solutions should be performed at a rate of 2 g of dry residue per 1 kg of body weight per day under the control of serum sodium concentration. Infusion therapy is performed until clinical improvement (restoration of consciousness, reduction of hyperthermia, normalization of blood pressure and diuresis).

In case of respiratory, hemodynamic and neurological symptoms disorders, oxygen therapy is prescribed, and, if indicated, artificial ventilation.