Pediatric Heat Stroke and Heat Syndrome
Introduction
Introduction to heat stroke and heat syndrome in children People are warm-blooded animals. No matter how much the outside temperature changes, through the regulation of the hypothalamic body temperature regulation center, the body temperature can be maintained at around 36-37 °C under normal conditions, but the human body has a certain degree of increase and duration of the ambient temperature. Tolerance limit, the body is in a high temperature environment for a long time, the body loses the regulation and compensation function, and the activity time is too long in the high temperature, high humidity environment or under the direct sunlight, which causes the body temperature regulation function to be disordered, causing water and electrolyte metabolism disorder and When a series of symptoms such as nervous system dysfunction, that is, heatillness or summer fever, the patients with acute onset and severe illness are generally referred to as heat stroke. The onset is slow, the symptoms are mild, and the longer duration is called heat syndrome. In recent years, due to the improvement of living standards and the large number of applications of air conditioners, the incidence rate has decreased significantly. basic knowledge Sickness ratio: 0.1% Susceptible people: children Mode of infection: non-infectious Complications: dehydration, metabolic acidosis, high fever in children, brain edema, shock
Cause
Causes of heat stroke and heat syndrome in children
(1) Causes of the disease
The occurrence of this disease is directly related to the high temperature, high humidity and low air pressure.
(two) pathogenesis
In high temperature environment, the convective heat dissipation method of the body surface - radiation and conduction obstacles, can only evaporate and dissipate heat through sweating. When the body exceeds the compensatory ability, the body temperature begins to rise, and at the same time, the liquid in the body is lost a lot; when the temperature is high, the temperature is high. When the wet environment exists at the same time, not only the radiation and conduction heat dissipation will be hindered, but also the evaporation and heat dissipation of the sweat will be affected, so that the residual heat in the body will accumulate in a large amount, the body temperature will rise rapidly, and a large amount of heat will be stored in the skin, and abnormal body temperature may occur in different parts, such as The temperature of the sputum is higher than the temperature of the anus or the temperature of the anus is only slightly higher than the abnormal temperature of less than 0.5 °C. The central nervous system of the infant is underdeveloped, the function of the sweat gland is insufficient, the sweat or sweat is less, and it is not easy to dissipate heat. The heat regulation of the hot weather is invalid, and heatstroke or heat syndrome is prone to occur. When the age is 3 to 4 years old, the regulation function is mature and rare, but the body temperature regulation function of the baby in the first few months is also poor. Why is it very rare to explain? It may be related to less infant activity and less heat production.
High fever causes central nervous system excitement, endocrine system activity, protein and carbohydrate catabolism, etc., which increases heat production and further impairs body temperature regulation.
The most common hazards of heat stroke are systemic tissue congestion, hemorrhage and degeneration, severe cell structure and enzyme function, cerebral vascular congestion can cause brain edema; cardiovascular system can have subendocardial hemorrhage, myocardial cell damage; liver and kidney are also often There is congestion and cell degeneration or necrosis.
Prevention
Child heat stroke and heat prevention
Minimize your child's play in the hot sun or in poorly ventilated areas during the hot summer months; don't wear thick and poorly ventilated clothes; always take a little salty salty water when you sweat for a long time, and use ventilation to keep your skin cool; For primary and secondary school students who participate in agricultural labor under the arduous heat, they should arrange labor time reasonably, wear straw hats when working, and supply cold salt boiled water or mung bean soup in time; when children are found to have a sign of heatstroke, they should leave the scene quickly; Children with medical history migrate to the shaded areas as much as possible in the summer.
Complication
Heat stroke and heat complications in children Complications, dehydration, metabolic acidosis, hyperthermia, cerebral edema, shock
Heat stroke due to high fever, dehydration, acidosis, blood concentration or increased viscosity can induce DIC, so that the condition suddenly deteriorates, or even death, easy secondary breathing, circulatory failure, convulsions, cerebral edema, shock, etc., heat syndrome lasting Can not be retired can be pale, thin and so on.
Symptom
Symptoms of heatstroke and heat syndrome in children Common symptoms High fever, irritability, restlessness, irregular, hot coma, dehydration, drowsiness, startle, loss of appetite, convulsions
1. Heatstroke: Any child who has a high temperature environment or has a history of exposure to the sun in the hot sun, elevated body temperature, sweating, dehydration with irritability, lethargy, muscle twitching or disturbance of consciousness, should consider heat stroke, elevated body temperature is heat stroke One of the main features, the higher the body temperature, the longer the duration, the worse the prognosis, the body temperature of 41 ° C is a dangerous indicator, often coma or convulsions, if the ultra-high fever does not retreat for several hours, survivors may leave permanent brain damage When the body temperature is as high as 42 °C, it is easy to cause central respiratory and respiratory failure leading to death; the body loses a lot of sodium chloride and may also have paroxysmal limb muscle spasm and convulsions; due to high fever, dehydration, acidosis, blood concentration or thickening Increased degree can induce DIC, causing sudden deterioration of the condition and even death.
2. Heat syndrome: Children with heat syndrome are more likely to have fever in midsummer. Most of the sick children occur from around the age of 2 to 2 years old, less than 6 months and more than 3 years old.
(1) Body temperature: between 38 and 40 °C, it can be a retention type, a relaxation type or an irregular heat type, which does not retreat. The hotter the weather, the higher the body temperature, and the fever period can be as long as 1 to 3 months. When the climate is cool, it naturally declines. Wuhan pediatrician has observed some of the sick children who have not been retired for a long time. After moving to Lushan, the body temperature drops to normal.
(2) Drinking more urine: Although the child has sweat gland dysfunction, but the kidney function is normal, so polyuria, urine clear and frequent, although the urine volume is not as much as diabetes insipidus, can also be more than 20 times in a day and night, no Containing protein, the specific gravity of urine is usually below 1.008; due to the decrease of water between tissues, the secretion of saliva is reduced and the thirst is more than drink. The daily drinking can reach more than 3L.
(3) Less sweat or no sweat: Most of them do not sweat, only when the head is slightly sweaty at the onset.
(4) Other conditions: The general condition is good at the beginning of the disease, it is not obvious, or occasionally has symptoms of indigestion or a similar cold, but it is not serious. The physical examination has no other positive signs except for a little congestion in the pharynx. It can be seen when it is hot. Stunning, lethargy, rare neurological symptoms, loss of appetite, paleness, weight loss, irritability, chronic illness, except for the percentage of lymphocytes in some cases, the laboratory test results are mostly normal Within the scope.
(5) Course of disease: Most of them last for 1 to 2 months, but can last up to 3 to 4 months, until the fever or other symptoms gradually subsided after leaving the high temperature environment or autumn cold.
Examine
Examination of heat stroke and heat syndrome in children
Due to excessive sweating or hypotonic loss due to excessive sweating and rapid breathing, blood pH is lowered, blood sodium is low, blood urea nitrogen is high, and serum aspartate aminotransferase (SGOT) or lactate dehydrogenase (LDH) can be increased. There may be proteinuria, heatstroke due to high fever, dehydration can be manifested as elevated blood sodium, increased plasma osmotic pressure, renal function in children with heat syndrome, so polyuria, no protein, urine specific gravity is often below 1.008.
Routine X-ray, ECG, brain CT, B-ultrasound.
Diagnosis
Diagnosis of heatstroke and heat syndrome in children
diagnosis
Those who have a high temperature environment or a history of exposure to the sun in the hot sun and the above clinical manifestations, heat stroke is easy to diagnose, only a long time of fever, and generally good, and other causes of fever, can be diagnosed with heat syndrome.
Differential diagnosis
Pay attention to detailed and comprehensive physical examination and laboratory blood, urine and other routine examinations, in order to exclude various infections, should be used for tuberculin test and lung X-ray examination to eliminate tuberculosis, fat reaction to identify typhoid, paratyphoid, blood The smear was examined for abnormal lymphocytes to exclude infectious mononucleosis.
