Heat stroke is the result of overheating of the body, sudden general hyperthermia, accompanied by a violation of the functions of various organs and systems. The reason is intense heat exposure and low rate of adaptation to elevated ambient temperature. It can be accompanied by asphyxia, convulsions, hallucinations, delirium, nausea, vomiting and loss of consciousness. In severe cases, coma and death are possible. The diagnosis is made on the basis of anamnesis and clinical picture. The treatment is conservative.
T67.0 Heat and sunstroke
Heat stroke is a state of hyperthermia caused by intense heat exposure and accompanied by disruption of the activity of various organs and systems. It can occur in people of any age and gender, but children, obese patients and elderly patients are more likely to suffer. In the first case, this is due to immature mechanisms of thermoregulation of the body, in the second – increased stress on the thermoregulation system and the cardiovascular system, in the third – poor physical fitness and the presence of various chronic diseases.
Unlike sunstroke, heat stroke does not necessarily occur under the influence of sunlight. It can develop both outdoors and indoors, both in sunny and cloudy weather. The emergence of this condition can be facilitated by the conditions of professional activity, for example, working in a hot shop or on a construction site (in the summer). In mild cases, help can be provided independently, with severe heat strokes, treatment with the participation of emergency physicians and resuscitators is necessary.
Heat stroke causes
There are two main, often closely related causes of the development of heat stroke: thermal exposure and insufficient speed of adaptation of the body to adverse environmental conditions. The probability of development and the degree of impact depend on the duration of a person’s stay in conditions of elevated ambient temperature, the intensity of thermal exposure, the age of the person, the individual characteristics of his body (allergic reactions, weather sensitivity, etc. D.), taking certain medications (MAO inhibitors, tricyclic antidepressants, amphetamines), alcohol and narcotic drugs, the presence or absence of chronic diseases of internal organs.
People suffering from hypertension, cardiovascular diseases, thyroid diseases, diabetes mellitus and some other endocrine diseases, vegetative-vascular dystonia, bronchial asthma, neuropsychiatric diseases, anorexia, cirrhosis of the liver, hepatitis, anhidrosis, hyperhidrosis, as well as those who have recently suffered a stroke or myocardial infarction are more susceptible to heat stroke.
In addition, the number of adverse circumstances include overweight, metabolic disorders, age less than 6-7 years, old age and pregnancy. Predisposing factors are high physical activity (sports, hard work), high humidity, too warm or too closed clothes with the effect of a “greenhouse”, severe dehydration, the period of acclimatization when moving or going on vacation to a country with a hot climate.
According to Adjaev’s classification, there are four degrees of overheating of the body. At the first degree (stable adaptation), which is observed at an ambient temperature of about 40 degrees, there is a normal heat transfer, adequate to the thermal load on the body. Heat is removed by evaporation of moisture from the respiratory tract and from the skin. The condition is satisfactory, subjective complaints of discomfort due to too high external temperature are possible. Often there is an unwillingness to move, lethargy, drowsiness.
With the second degree (partial adaptation), the ambient temperature is about 50 degrees. In these conditions, the body does not have time to compensate for the heat load by evaporation of moisture, heat accumulates in the body. There may be an increase in body temperature to 38.5 degrees, an increase in systolic pressure by 5-15 mm Hg and a decrease in diastolic pressure by 10-20 mm Hg. There is an increase in pulmonary ventilation, an increase in minute and systolic cardiac volume, an increase in pulse rate by 40-60 beats / min, profuse sweating and redness of the skin.
At the third degree (failure of the device), the ambient temperature reaches 60 degrees or more, the body temperature can rise to 39.5-40 degrees. There is an increase in systolic pressure by 20-30 mm Hg and a decrease in diastolic pressure by 30-40 mm Hg. Sometimes there is an effect of “infinite tone” (diastolic pressure is not determined). Systolic cardiac volume decreases, the pulse rate increases to 160 beats/min. Pulmonary ventilation is sharply enhanced. The skin is red, covered with sweat drops. The victim complains of headache, pressure in the temples, palpitations and a feeling of intense heat. Motor restlessness may be observed.
At the fourth degree (absence of adaptation), heat stroke itself develops, a condition accompanied by severe disturbances in the activity of the nervous, cardiovascular and other systems. In severe cases, acidosis, DIC syndrome and renal failure are observed. Possible brain hemorrhage or pulmonary edema. Hypofibrinogenemia, leukocytosis and thrombocytopenia are determined by blood analysis, proteinuria, leukocyturia and cylindruria are determined by urine analysis. One of the dangerous complications is heart failure, which occurs due to a sharp drop in blood pressure, a decrease in the filling and speed of blood flow and deterioration of microcirculation, accompanied by the rapid development of dystrophic changes in the heart tissue.
Taking into account the leading symptoms in intensive care, traumatology and orthopedics, there are four forms of heat stroke:
- Pyretic form – the most striking symptom is an increase in body temperature to 39-41 degrees.
- Asphyxic form – respiratory depression comes to the fore.
- Cerebral or paralytic form – convulsions occur against the background of hyperthermia and hypoxia, sometimes hallucinations and elements of delirium appear.
- Gastroenteric or dyspeptic form – accompanied by nausea, vomiting, diarrhea and urinary retention.
Heat stroke symptoms
There are three clinical degrees of pathology severity. At the first degree, there is rapidly increasing weakness, lethargy, drowsiness, a dull aching headache, a feeling of heaviness in the chest, the need to breathe deeply, mild or moderate nausea. The skin is pale, covered with drops of sweat, the pupils are dilated, there is an increase in breathing and pulse. Body temperature is usually within the normal range.
The second degree is accompanied by a feeling of pronounced muscle weakness, noise and ringing in the ears. It is difficult for the victim to move, it is difficult to raise his head or arms. The headache becomes diffuse, more intense. Nausea increases, vomiting is possible. Breathing is intermittent, rapid. Pronounced tachycardia. Dehydration and impaired coordination of movements (static and dynamic ataxia) are detected. Body temperature increased to 39-40 degrees. Fainting is possible.
At the third degree, there is a sharp change in the color of the skin – from hyperemia to cyanotic. There is anxiety and psychomotor agitation. Breathing is shallow, pulse is thready, reflexes are weakened. Possible clonic-tonic seizures, delirium, kinesthetic, auditory and visual hallucinations. The body temperature is sharply elevated. In the absence of qualified help, coma and death occur.
In children, due to the immaturity of thermoregulation mechanisms, heat stroke can develop at a relatively low ambient temperature and a fairly short thermal exposure. With a mild degree of heat stroke, the baby becomes moody, sluggish, complains of nausea and headache, does not want to play, tries to lie down, loses appetite. The pulse is rapid, the face is hyperemic, the pupils are dilated. The skin is sweaty, hot to the touch, while the body temperature usually does not exceed 37 degrees. Vomiting and nosebleeds are often observed.
With moderate severity, headache, lethargy and poor health, impaired coordination of movements, unsteadiness of gait, tachycardia, difficulty breathing and frequent vomiting are noted. The body temperature is raised to 39 degrees, some victims have fainting spells. In severe cases, a feverish condition develops, convulsive syndrome is observed, body temperature is elevated to 40-41 degrees, coma is possible.
The diagnosis is established on the basis of a characteristic anamnesis, patient complaints and the results of an objective examination. To assess the severity of the condition, body temperature is measured, pulse and blood pressure are determined. If there are signs of damage to various organs and systems, appropriate instrumental and laboratory tests are prescribed.
Heat stroke treatment
It is necessary to move the victim to a cool place as soon as possible, remove excess clothing, put cool compresses on the forehead, chest area, groin area, hands, calves and armpits. Compresses should be exactly cool, but by no means icy, since the temperature contrast can provoke vascular collapse. If possible, repeated wipes can be carried out with a weak vinegar solution or ordinary water. The patient should be given plenty of drink: weak sweet tea, non-carbonated mineral water or purified water. In case of cardiac disorders, corvalol, cordiamine or validol should be used and an ambulance should be called immediately.
In case of fainting, the victim is laid down, slightly lowering his head and lifting his legs. Cold compresses are applied to the temples, ammonia is brought to the nose. Gently slap the patient on the cheeks or massage the auricles. After coming out of a swoon, they give sweet tea. In case of heat stroke, in no case should alcohol, strong tea or coffee be given to the victim – this can worsen his condition and provoke an aggravation of cardiac disorders.
Qualified medical care in case of heat stroke is provided by ambulance staff, resuscitators, cardiologists and other specialists. If necessary, indirect heart massage is performed, artificial respiration is performed. Intravenous injections of saline solutions are carried out, cordiamine is subcutaneously injected to normalize cardiac activity. In severe cases, the victim is hospitalized, resuscitation measures are carried out, including intubation, catheterization of the subclavian vein with subsequent infusion of solutions, stimulation of cardiac activity, oxygen therapy, etc.
Prognosis and prevention
The prognosis is usually favorable. Prevention of heat stroke consists in the use of clothing made of natural materials, regular ventilation or installation of air conditioners, the use of a sufficient amount of liquid, the exclusion of heavy physical exertion in the hottest hours, wearing light hats while outdoors. When working in high heat conditions, you should take short breaks every hour and choose suitable workwear.
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