What is hyperthermia in medicine? Malignant hyperthermia

Hyperthermia is a pathological process characterized by an increase in body temperature. However, the level of increase depends on certain conditions environment. Hyperthermia is a dangerous condition because, unlike fever, there is a malfunction in the functioning of thermoregulatory mechanisms.

Thermoregulation mechanism

Hyperthermia develops in situations where human body cannot, for any reason, release excess heat outside, that is, the normal relationship between two processes is disrupted: heat transfer and heat production.

Regulation of the amount of heat transfer is carried out due to various physiological reactions. Among them, the vasomotor reaction is of primary importance. When the body overheats, a decrease in capillary tone occurs skin, which increases the speed of blood flow in them. So only through the vessels of the hands can our body remove about 60% of the heat it produces.

Others important mechanisms heat transfer is sweating and evaporation of moisture from the mucous membranes.

Types of hyperthermia

Depending on the reason that caused the increase in body temperature, the following types of hyperthermia are distinguished:

Endogenous or toxic hyperthermia;
Exogenous or physical hyperthermia;
Pale hyperthermia. This type hyperthermia occurs as a result of significant irritation of sympathoadrenal structures, which causes a sharp spasm of blood vessels.

Pathogenesis of hyperthermia

The exogenous type of hyperthermia occurs when a person spends a long time in conditions of high humidity and elevated temperature. This leads to overheating of the body and development heatstroke. The main link in the pathogenesis of hyperthermia in this case is a disorder of normal water and electrolyte balance.

With the toxic type of hyperthermia, excess heat is produced by the body itself, and it does not have time to remove it outside. Most often, this pathological condition develops against the background of certain infectious diseases. The pathogenesis of endogenous hyperthermia is that microbial toxins are able to increase the synthesis of ATP and ADP by cells. The breakdown of these high-energy substances releases a significant amount of heat.

Symptoms of physical and toxic hyperthermia

Symptoms and stages of endogenous and exogenous hyperthermia, as well as their clinical picture similar. The first stage is called adaptive. It is characterized by the fact that at this moment the body is still trying to regulate temperature due to:

Increased sweating;
Tachypnea;
Dilation of skin capillaries.

Patients complain of headache and muscle pain, weakness, nausea. If he is not provided with emergency assistance, the disease enters the second stage.

This is called the arousal stage. Body temperature rises to high values(39 - 40 degrees C). The patient is adynamic, stunned. Complains of nausea and severe headache. Sometimes there may be short-term episodes of loss of consciousness. Breathing and pulse are increased. The skin is moist and hyperemic.

During the third stage of hyperthermia, paralysis of the vasomotor and respiratory centers develops, which can lead to the death of the patient.

Hypothermia of the physical and toxic type is accompanied, as we have already said, by redness of the skin and therefore it is called “pink”.

Pale type of hyperthermia

Pale hyperthermia or hyperthermic syndrome occurs as a result of pathological activity of the thermoregulation center. The development may be caused by some infectious diseases, as well as by the administration of medications that have a stimulating effect on the sympathetic part. nervous system or having an adrenergic effect. In addition, the causes of pale hyperthermia general anesthesia with the use of muscle relaxants, traumatic brain injuries, brain tumors, that is, all those conditions in which the functions of the hypothalamic temperature regulation center may be impaired.

The pathogenesis of pale hyperthermia consists of a sharp spasm of skin capillaries, which leads to a significant decrease in heat transfer and, as a result, increases body temperature.

With pale hyperthermia, the body temperature quickly reaches life-threatening values - 42 - 43 degrees C. In 70% of cases, the disease ends in death.

Therapeutic hyperthermia

Therapeutic hyperthermia is one of the methods of therapy malignant neoplasms. It is based on the fact that the patient’s entire body or individual parts of it are exposed to high temperatures, which ultimately increases the effectiveness of radiation or chemotherapy.

The effect of the method of therapeutic hyperthermia is based on the fact that high temperatures are more destructive for actively dividing cancer cells than for healthy people.

Currently, therapeutic hyperthermia is used to a limited extent. This is explained not only by the technical complexity of the method, but also by the fact that it has not been fully studied.

Signs of difference between hyperthermia and fever:

Caused by various etiological factors.
With fever, patients complain of chills. Moreover, for every degree increase in temperature, their pulse rate increases by 8 - 10 beats, and their breathing rate increases by two to three chest excursions. With hyperthermia, patients note a feeling of heat and significant sweating. Heart rate and breathing movements increases significantly.
Physical methods of cooling the body during fever do not affect the temperature, while during hyperthermia they lead to a decrease in temperature.
For hyperthermia, antipyretic drugs are not effective. During fever, they quickly normalize body temperature.
An increase in temperature during fever is associated with the activation of oxidative phospholation processes, against the background of which the synthesis of ATP increases, and also stimulates protective forces body. The pathogenesis of hyperthermia, on the contrary, consists in blocking the synthesis of ATP and increasing the breakdown of already existing “energy” molecules. This leads to rapid increase temperature.

Providing emergency care for hyperthermia

When the body is elevated, the first thing to do is to find out whether it is caused by fever or hyperthermia. This is due to the fact that in case of hyperthermia, measures to reduce the elevated temperature should be immediately started. In case of moderate fever, on the contrary, it is not necessary to urgently lower the temperature, since its increase has a protective effect on the body.

Since the pathogenesis of hyperthermia of the “pink” and “pale” types is different, medical care for patients will be provided differently.

Algorithm of actions for providing emergency care for “Pink” hyperthermia:

Open the patient and ventilate the room, as this will enhance heat transfer processes;
Assign drinking plenty of fluids cool liquid;
The patient's body is blown with a fan, and ice packs are applied to the skin above the projection of large blood vessels.
Setting up enemas with cool water(about 20 degrees C).
Intravenous infusion of cooled solutions.
If the above measures are ineffective, do shared bath with cool water (temperature no higher than 32 degrees C).
Non-steroidal anti-inflammatory drugs are prescribed.

Algorithm for providing emergency care for pallid hyperthermia:

Non-steroidal anti-inflammatory drugs are given internally;
Papaverine or no-spa are injected intramuscularly, which reduces vascular spasm;
Rub the skin of the torso and limbs. You can apply heating pads to your feet.
After the transition of pale hyperthermia to pink treatment continue according to the algorithm described above.

Algorithm for providing emergency care for toxic hyperthermia:

Urgently call a resuscitation team to the patient;
Provide venous access and begin infusion saline solutions and glucose.
Antipyretic drugs and antispasmodics are administered intramuscularly.
If there is no effect from the therapy, droperidol is administered intravenously.
If seizures occur, they are stopped intravenous administration relanium.
Oxygen therapy.
If indicated, it is necessary to perform tracheal intubation and transfer the patient to artificial ventilation.
Prescription of dantrolene.

What is hyperthermia? This is the accumulation of excess heat in the body. Speaking in simple language- this is overheating. Body temperature rises, its release into external environment. There is also another situation - excess heat coming from outside. Similar condition appears when heat production prevails over its consumption. The appearance of this problem negatively affects the functioning of the entire body. The circulatory and cardiovascular systems are under great strain. Hyperthermia according to ICD-10 is a fever of unknown origin, which can also occur after childbirth. Unfortunately, this also happens.

Types of hyperthermia

They are as follows:

Red. Considered the safest. There is no circulatory disturbance. Peculiar physiological process cooling the body, which prevents overheating internal organs. Signs - skin color changes to pink or red, the skin is hot when touched. The person himself is hot and sweating profusely.
White. When talking about what hyperthermia is, we cannot ignore this type. It poses a danger to human life. Peripheral vasospasm occurs circulatory system, which leads to disruption of the heat transfer process. If this condition lasts for a long time, it will inevitably lead to swelling of the brain, impaired consciousness and the appearance of seizures. The person is cold, his skin becomes pale with a bluish tint.
Neurogenic. The cause of its appearance is a brain injury, benign or malignant tumor, local hemorrhage, aneurysm. This species is the most dangerous.
Exogenous. Occurs when the ambient temperature rises, which contributes to the entry of a large amount of heat into the body.
Endogenous. A common cause of appearance is toxicosis.

Why is there a problem?

The human body can regulate the temperature of not only the entire body, but also the internal organs. This event involves two processes - heat production and heat transfer.

Heat is produced by all tissues, but the liver and skeletal muscles are most involved in this work.

Heat transfer occurs thanks to:

Small blood vessels, which are located near the surface of the skin and mucous membranes. When expanding, they increase heat transfer, and when narrowing, they reduce it. The hands play a special role. Through small vessels located on them, up to sixty percent of the heat is removed.
Skin. He contains sweat glands. As the temperature rises, sweating increases. This leads to cooling. The muscles begin to contract. The hairs growing on the skin rise. This way the heat is retained.
Breathing. When you inhale and exhale, liquid evaporates. This process increases heat transfer.

There are two types of hyperthermia: endogenous (impaired heat transfer occurs under the influence of substances produced by the body itself) and exogenous (arising under the influence of environmental factors).

Causes of endogenous and esogenous hyperthermia

The following reasons are identified:

Excess hormones from the adrenal glands, ovaries, thyroid gland. Endocrine pathologies these organs provoke increased heat production.
Reduced heat transfer. An increase in the tone of the nervous system causes a narrowing of blood vessels, which leads to their sharp spasm. For this reason, the temperature jumps up within a few minutes. On the thermometer scale you can see 41 degrees. The skin becomes pale. That is why this state Experts call it pale hyperthermia. The reason that most often provokes this problem is obesity (third or fourth degree). Subcutaneous tissue overweight people are highly developed. Excess heat cannot “break through” through it. It stays inside. An imbalance of thermoregulation occurs.

Exogenous heat accumulation. Factors that provoke it:

Finding a person in a room with high temperature. This could be a bathhouse, a hot shop. Long stays under the hot sun are no exception. The body is unable to cope with excess heat, and a failure occurs in the process of heat transfer.
High humidity. The pores of the skin begin to become clogged, sweating does not occur in in full. One component of thermoregulation does not function.
Clothing that does not allow air and moisture to pass through.

Main factors causing the problem

The main causes of hyperthermia syndrome include the following:

Brain damage.
Ischemic or hemorrhagic stroke.
Disease respiratory tract.
Food intoxication and pathological processes occurring in the urinary system.
Viral infection and skin diseases with suppuration.
Lesions of abdominal and retroperitoneal organs.

Let's move on to a more detailed study of the causes of hyperthermia:

Stages of hyperthermia

Before determining what kind of help to provide for hyperthermia, let's talk about its stages. This is what determines which treatment methods to use.

Adaptive. Tachycardia appears rapid breathing, vasodilation and heavy sweating. These changes themselves try to normalize heat transfer. Symptoms: headache, muscle pain, weakness. If help is not provided in time, the disease enters the second stage.
Excitement stage. Appears heat(up to thirty-nine degrees and more). There is confusion, increased heart rate and breathing, increased headache, weakness and nausea. The skin is pale and damp.
The third stage is characterized by respiratory and vascular paralysis. This condition is very dangerous for human life. It is at this moment that emergency assistance for hyperthermia is needed. Delay may result in death.

Pediatric hyperthermia

An elevated temperature in a child indicates some disease or inflammatory process occurring in the baby’s body. In order to help him, it is necessary to establish a diagnosis and determine what ailment the existing symptoms relate to.

Hyperthermia in children is very dangerous. It can lead to complications. This means it requires urgent treatment. Symptoms of hyperthermia in a child are as follows:

Temperature above thirty-seven degrees. This indicator can be measured in a child: in the groin, in the mouth, in the rectum.
Breathing is rapid, as is heartbeat.
Sometimes convulsions and delirium appear.

If your body temperature is not higher than thirty-eight degrees, experts recommend not lowering it. The baby's body must fight on its own. Interferon is produced, which strengthens the child’s defenses

But every rule has an exception. If a child suffers from disorders of the central nervous system, then already at thirty-eight degrees the temperature should be reduced.

How to help your baby

For hyperthermia in children, emergency care is as follows.

1. Red type of disease:

The child is given a cool drink.
Under no circumstances should you wrap your baby up; on the contrary, remove excess clothing. Excess heat will escape through the skin.
Cool lotions are placed on the child's forehead.
Cool bandages on your wrist will help reduce your temperature.
If the temperature rises to thirty-nine degrees, give your child antipyretic medications.

2. White hyperthermia. In this case, you should act a little differently:

The baby is given a warm drink.
It is advisable to rub the limbs to help the child warm up.
You should wear warm socks on your feet.
It wouldn't hurt to wrap your child up or dress him warmer.
Raspberry tea is suitable to reduce the temperature. This is a product that has been proven over the years.

If all these actions did not help bring down the temperature, then next step- health care.

A little more about children

Now we will talk about hyperthermia in newborns. Sometimes parents of babies start to panic for no reason. To prevent this from happening, you should familiarize yourself with this information.

The baby has a temperature of thirty-seven degrees. First, pay attention to your baby's behavior. If he is calm, eats and sleeps well, smiles and is not capricious, then there is no need to worry in advance. Remember that a temperature of thirty-seven degrees in a child up to a month is normal.

Is a temperature of thirty-seven degrees dangerous for a newborn? As stated above, no. The baby's body adapts to the environment. That's why the temperature periodically jumps.

It doesn’t hurt to know that a baby with a body temperature of thirty-seven degrees can be bathed. Don't worry about what happens after water procedures she stood up a little. Physical activity and warm water lead to temporary hyperthermia.

Temperature fluctuations in children under one year of age are normal. During this period, thermoregulation is just beginning to form. But if the temperature has exceeded thirty-seven, then you can’t do without medical help. Especially if other symptoms begin to appear: pallor or redness of the skin, moodiness, lethargy, refusal to eat.

Genetic disease

Malignant hyperthermia is hereditary. Most often found in anesthesiology. There is a disruption in muscle tissue metabolic processes. The danger of this condition is that during the use of anesthesia or anesthesia, the heart rate increases, the temperature rises greatly, and shortness of breath appears. If timely assistance is not provided, the person may die.

The disease is inherited through generations. If one of the relatives has been diagnosed with it, then the person automatically falls into the risk zone. During anesthesia, medications are used that will not provoke an attack.

Now about the symptoms of the disease:

In the exhaled air a large number of carbon dioxide.
Breathing is rapid and shallow.
Heart rate is more than ninety beats per minute.
The temperature rises sharply to forty-two degrees.
The skin turns blue.
A spasm of the chewing muscles appears and the tone increases.
There are surges in blood pressure.

Malignant hyperthermia: treatment and complications

For malignant hyperthermia, emergency care should be provided immediately. Treatment of this disease consists of two stages.

Rapid cooling, maintaining this state.
Administration of the drug "Dantrolene".

The first stage is necessary to prevent damage to the central nervous system and metabolic disorders.

The second stage is an addition to the first.

The best results can be obtained if muscle tone has not reached the generalized stage.

This type of hyperthermia has a high mortality rate. That is why it is necessary to immediately take all measures to prevent an attack.

During the operation, the anesthesiologist has everything at hand necessary medications to relieve an attack. Instructions are also included with them.

The same manipulations are carried out if malignant hyperthermia occurs in children.

To complications of this disease can be attributed:

Kidney failure.
Destruction of muscle cells.
Blood clotting disorder.
Arrhythmia.

First aid for hyperthermia

Before it is rendered medication assistance with a sharp increase in temperature, a person should be helped where his illness overtook him.

Take off excess clothes. If a person is under the hot sun, he should be moved to the shade. In the room, open a window or point a fan at the patient. Give the person plenty of fluids. If the skin is pink, the drink should be cool. If pale, the liquid should be warm.

IN groin area, under your arm, on your neck, place a heating pad with ice or frozen foods. The body can be wiped with a solution of table vinegar or vodka.

For pallid hyperthermia, treatment involves warming the extremities. Vascular spasm is eliminated, the process of thermoregulation is normalized.

Drug treatment is provided in a hospital or by an ambulance:

For pale hyperthermia, antispasmodics are administered. When red - cool solutions.
If the attack began during surgery, the person is assisted by the resuscitation team. The patient is given infusion solutions and anti-seizure drugs.

Diagnostics

Fever is a symptom of many diseases. To identify the cause, a comprehensive examination should be carried out.

An anamnesis is being collected.
The patient is examined.
Tests are prescribed: blood, urine.
A chest x-ray is required.

For determining pathological changes a bacteriological or serological study is prescribed.

You already know what hyperthermia is. As you can see, this disease is not to be joked about. If the temperature cannot be brought down, seek medical help immediately.

Hyperthermia is an increase in human body temperature above 37.5ºC. The normal human body temperature is considered to be 36.6ºC. Body temperature can be measured in oral cavity, in the groin, in axillary area or the patient's rectum.

Hyperthermia is accompanied by an increase and qualitative violations metabolism, loss of water and salts, impaired blood circulation and oxygen delivery to the brain, causing agitation, sometimes convulsions and fainting. High temperature with hyperthermia is more difficult to tolerate than with many febrile diseases.

Hyperthermic syndrome. Hyperthermia syndrome is understood as an increase in body temperature above 39°C, accompanied by disturbances in the hemodynamics and central nervous system. Most often, hyperthermic syndrome occurs with neurotoxicosis associated with acute infections, and can also be during acute surgical diseases(appendicitis, peritonitis, osteomyelitis, etc.). A decisive role in the pathogenesis of hyperthermic syndrome is played by irritation of the hypothalamic region as the center of thermoregulation of the body.

Heatstroke. Variety clinical syndrome hyperthermia. There are load and non-load thermal shocks. The first type usually occurs in young people with large physical activity in conditions where the outflow of heat is difficult for one reason or another (hot weather, stuffy room, etc.). The non-stress version of heat stroke usually occurs in the elderly or sick at high ambient temperatures: 27-32 C. The cause of heat stroke in such cases is a defect in the thermoregulation system. The usual clinical picture in both variants is stupor or coma. If there is a delay in providing assistance, the mortality rate can reach 5%.

Symptoms. Feeling of heaviness in the head, nausea, vomiting, cramps. Confusion quickly sets in, then loss of consciousness. There is an increase in heart rate and respiration. Most patients experience a decrease in blood pressure, but it is also possible to increase it; Multiple hemorrhages appear on the mucous membranes.

Hyperthermia malignant. A type of clinical hyperthermia syndrome. Occurs approximately 1 time per 100 thousand anesthesia when using depolarizing muscle relaxants (ditilin, listenone, myorelaxin, etc.) and inhalational anesthetics from the group of halogen-substituted hydrocarbons (fluorogan, halothane, methoxyflurane, etc.). Hyperthermia occurs in patients with hypersensitivity to these drugs, which is associated with disorders of calcium metabolism in muscles. The consequence is generalized muscle twitching and sometimes widespread muscle contracture, resulting in a large amount of heat and body temperature quickly reaching 42°C at an average rate of 1 C/min. Mortality even in recognized cases reaches 20-30%.

Therapeutic hyperthermia. Therapeutic hyperthermia is one of the methods of treating malignant neoplasms. It is based on the fact that the patient’s entire body or local areas are exposed to high temperatures, which ultimately increases the effectiveness of radiation or chemotherapy. The effect of the therapeutic hyperthermia method is based on the fact that high temperatures are more destructive for actively dividing cancer cells than for healthy ones. Currently, therapeutic hyperthermia is used to a limited extent. This is explained not only by its technical complexity, but also by the fact that it has not been fully studied.

Fevers also differ in type:

Pink hyperthermia, at which heat production is equal to heat transfer and general state however, it has not been changed.

White hyperthermia, in which heat production exceeds heat transfer, as spasm of peripheral vessels occurs. With this type of hyperthermia, coldness of the extremities, chills are felt, pallor of the skin, a cyanotic tint of the lips and nail phalanges are observed.

Types of hyperthermia

Exogenous or physical hyperthermia. The exogenous type of hyperthermia occurs when a person spends a long time in conditions of high humidity and elevated temperature. This leads to overheating of the body and the development of heat stroke. The main link in the pathogenesis of hyperthermia in this case is a disorder of normal water and electrolyte balance.

Endogenous or toxic hyperthermia. With the toxic type of hyperthermia, excess heat is produced by the body itself, and it does not have time to remove it outside. Most often, this pathological condition develops against the background of certain infectious diseases. The pathogenesis of endogenous hyperthermia is that microbial toxins are able to increase the synthesis of ATP and ADP by cells. The breakdown of these high-energy substances releases a significant amount of heat.

Pale hyperthermia

This type of hyperthermia occurs as a result of significant irritation of the sympathoadrenal structures, which causes a sharp spasm of the blood vessels.

Pale hyperthermia or hyperthermic syndrome occurs as a result of pathological activity of the thermoregulation center. The development may be caused by some infectious diseases, as well as by the administration of drugs that have a stimulating effect on the sympathetic part of the nervous system or have an adrenergic effect. In addition, the causes of pale hyperthermia are general anesthesia with the use of muscle relaxants, traumatic brain injury, stroke, brain tumors, that is, all those conditions in which the functions of the hypothalamic temperature regulation center may be impaired.

The pathogenesis of pale hyperthermia consists of a sharp spasm of skin capillaries, which leads to a significant decrease in heat transfer and, as a result, increases body temperature.

With pale hyperthermia, the body temperature quickly reaches life-threatening values - 42 - 43 degrees C. In 70% of cases, the disease ends in death.

Symptoms of physical and toxic hyperthermia

The symptoms and stages of endogenous and exogenous hyperthermia, as well as their clinical picture, are similar. The first stage is called adaptive. It is characterized by the fact that at this moment the body is still trying to regulate temperature due to:

Tachycardia;
Increased sweating;
Tachypnea;
Dilation of skin capillaries.

Patients complain of headache and muscle pain, weakness, and nausea. If he is not provided with emergency assistance, the disease enters the second stage.

This is called the arousal stage. Body temperature rises to high values (39 - 40 degrees C). The patient is adynamic, stunned. Complains of nausea and severe headache. Sometimes there may be short-term episodes of loss of consciousness. Breathing and pulse are increased. The skin is moist and hyperemic.

During the third stage of hyperthermia, paralysis of the vasomotor and respiratory centers develops, which can lead to the death of the patient.

Hypothermia of the physical and toxic type is accompanied, as we have already said, by redness of the skin and therefore it is called “pink”.

Causes of hyperthermia

Hyperthermia occurs at maximum exertion physiological mechanisms thermoregulation (sweating, dilation of skin vessels, etc.) and, if the causes that cause it are not eliminated in time, it steadily progresses, ending at a body temperature of about 41-42°C with heat stroke.

The development of hyperthermia is facilitated by increased heat production (for example, during muscle work), disruption of thermoregulation mechanisms (anesthesia, intoxication, some diseases), and age-related weakness (in children of the first years of life). Artificial hyperthermia is used in the treatment of certain nervous and sluggish chronic diseases.

First emergency aid for hyperthermia

Methods used to reduce temperature are divided into internal and external. The first include, for example, lavage ice water and extracorporeal blood cooling, however, it is impossible to carry them out on your own, and they can cause complications.

External cooling methods are easier to use, well tolerated and very effective.

Conductive cooling techniques include applying hypothermic packs directly to the skin and ice water baths. Alternatively, you can apply ice to your neck, armpits and groin area.
Convective cooling techniques include using fans and air conditioners, and removing excess clothing.
A cooling technique is also often used, which works by evaporating moisture from the surface of the skin. The person's clothes are removed, the skin is sprayed with cool water, and a fan is used for additional cooling or a window is simply opened.

Medication-induced fever reduction

For severe hyperthermia, provide supplemental oxygen and install a continuous 12-line ECG to monitor cardiac activity and signs of arrhythmia.
Use diazepam to relieve chills.
With “red” hyperthermia: it is necessary to expose the patient as much as possible, provide access fresh air(avoiding drafts). Prescribe plenty of fluids (0.5-1 l more age norm fluids per day). Use physical methods cooling (blowing with a fan, a cool wet bandage on the forehead, vodka-vinegar (9% table vinegar) rubbing - wipe with a damp swab). Prescribe paracetamol orally or rectally (Panadol, Calpol, Tylinol, Efferalgan, etc.) in a single dose of 10-15 mg/kg orally or in suppositories 15-20 mg/kg or ibuprofen in a single dose of 5-10 mg/kg (for children older than 1 year). If the body temperature does not decrease within 30-45 minutes, an antipyretic mixture is administered intramuscularly: 50% analgin solution (for children under 1 year of age, dose 0.01 ml/kg, over 1 year of age, dose 0.1 ml/year life), 2.5% solution of pi-polfen (diprazine) for children under one year of age at a dose of 0.01 ml/kg, over 1 year - 0.1-0.15 ml/year of life. A combination of drugs in one syringe is acceptable.
For “white” hyperthermia: simultaneously with antipyretics (see above) give vasodilators orally and intramuscularly: papaverine or noshpa at a dose of 1 mg/kg orally; 2% papaverine solution for children under 1 year - 0.1-0.2 ml, over 1 year - 0.1-0.2 ml/year of life or noshpa solution at a dose of 0.1 ml/year of life or 1% dibazole solution at a dose of 0.1 ml/year of life; you can also use a 0.25% solution of droperidol at a dose of 0.1-0.2 ml/kg intramuscularly.

Treatment of hyperthermia

Treatment of hyperthermia consists of eliminating the causes that caused hyperthermia in the body; cooling; if necessary, use dantrolene (2.5 mg/kg orally or intravenously every 6 hours).

What not to do with hyperthermia

Wrapping up the patient big amount warm things (blankets, clothes).

Use warming compresses for hyperthermia - they contribute to overheating.

Give very hot drinks.

Treatment of malignant hyperthermia

If the fact of rapidly progressing hyperthermia is established, the drugs listed above must be discontinued. Anesthetic agents that do not lead to hyperthermia include tubocurarine, pancuronium, nitrous oxide and barbiturates. They can be used if it is necessary to continue anesthesia. Due to the possibility of developing ventricular arrhythmia, prophylactic use of procainamide and phenobarbital in therapeutic doses is indicated. It is necessary to provide cooling procedures: placement over large blood vessels ice containers or cold water. Oxygen inhalation should be immediately established and sodium bicarbonate (3% solution 400 ml) should be administered intravenously. In severe cases, it is indicated resuscitation measures. Hospitalization is required in the intensive care unit.

Hyperthermia is overheating of the human body, which is accompanied by a temperature above 37ºC. Hyperthermia is the most common symptom various diseases and is a protective-compensatory reaction of the body.

Causes

Hyperthermia occurs in many diseases that are accompanied by inflammatory processes or damage to the thermoregulation center of the brain:

Inflammatory diseases of the respiratory tract
Acute viral infections respiratory tract
Inflammatory diseases of the ENT organs
Acute food poisoning
Acute inflammatory diseases abdominal region and retroperitoneal space
Strokes
Purulent diseases soft tissue
Stressful situations

Hyperthermia is based on an imbalance between heat production and heat loss that occurs as a result of diseases.

Symptoms

Explicit or hidden manifestation other symptoms of the disease that caused hyperthermia
Weakness, drowsiness, rarely - agitation
Rapid breathing
Sweating
Tachycardia
Children may experience seizures and loss of consciousness. At very high temperatures, loss of consciousness can also occur in adults.

Diagnostics

Temperature measurements can be taken in the mouth, groin, armpit or rectum.

Types of disease

Based on temperature indicators, hyperthermia is divided into:

Subfebrile (37.2-38°C)
Low (moderate) febrile (38.1-39°C)
High febrile (39.1-41°C)
Hyperthermic (above 41.1 °C)

The duration of hyperthermia can be:

Ephemeral (from several hours to 2 days)
Acute (up to 15 days)
Subacute (up to 45 days)
Chronic (over 45 days)

There are pink hyperthermia and white hyperthermia. In the first case, heat production is equal to heat transfer and the general state is not changed. In the second case, heat production exceeds heat transfer, as spasm of peripheral vessels occurs. In this case, coldness of the extremities, chills are felt, pale skin, a cyanotic tint of the lips and nail phalanges are observed.

Hyperthermia is also distinguished by the nature of the temperature curve.

Patient Actions

The patient needs to go to bed. There must be access to fresh air in the room where the patient is located. Drink as many warm drinks as possible.

If an adult continues to have hyperthermia above 39ºC for 24 hours, or due to the high temperature there is difficulty breathing, impaired consciousness, abdominal pain, vomiting, urinary retention, etc., you should urgently call a doctor or an ambulance.

Children are recommended to take measures to eliminate hyperthermia at temperatures above 38ºС-38.5ºС or lower if their general condition is impaired. If a child develops a rash, difficulty breathing, convulsions, or hallucinations due to high hyperthermia, call a doctor immediately.

If a child has febrile seizures, lay him on his back so that his head is turned to the side, open the window, unfasten constrictive clothing, protect the child from possible injuries during convulsive movements, call an ambulance.

Treatment

The temperature in children is usually reduced by paracetamol, ibuprofen and other drugs containing these active ingredients. The dosage and form of administration depends on age.

In adults, in addition to paracetamol and ibuprofen, acetylsalicylic acid preparations are also used.

Physical methods of combating hyperthermia include wiping the body with a cloth soaked in water at room temperature or in a solution of table vinegar and vodka. You can wrap a patient with hyperthermia in a wet sheet. An enema with boiled water room temperature.

It is necessary to find out the cause of the elevated temperature and decide on the treatment of the underlying disease.

Complications

In severe cases, hyperthermia is accompanied sudden loss consciousness and convulsions.

Hyperthermia is most dangerous for children and people with cardiovascular diseases. Even death is possible.

Prevention

Includes the prevention of diseases whose symptom is hyperthermia.

Fever is a very common symptom in critically ill patients. According to the literature, 26-70% of adult patients admitted to the departments intensive care, there is an increased body temperature.

And among neurocritical care patients, the frequency is even higher. Thus, body temperature > 38.3 °C is observed in 72% of patients with subarachnoid hemorrhage due to rupture of a cerebral aneurysm, body temperature > 37.5 °C - in 60% of patients with severe traumatic brain injury (TBI) .

The reasons for elevated temperature can be different. In patients with primary brain injury, the so-called centrogenic hyperthermic reaction (or neurogenic fever) may be one of them (in 4-37% of cases of traumatic brain injury (TBI)).

Classification of hyperthermic conditions

An increase in body temperature above normal is a cardinal sign of hyperthermic conditions. From the standpoint of the pathophysiology course, hyperthermia is a typical form of heat exchange disorder that occurs as a result of high ambient temperature and/or disruption of the body’s heat transfer processes; characterized by a breakdown of the mechanisms of thermoregulation, manifested by an increase in body temperature above normal.

There is no generally accepted classification of hyperthermia. In the domestic literature, hyperthermic conditions include:

overheating of the body (hyperthermia itself),
heatstroke,
sunstroke,
fever,
various hyperthermic reactions.

In the English-language literature, hyperthermic conditions are classified into hyperthermia and fever (pyrexia). Hyperthermia includes heat stroke, drug-induced hyperthermia (malignant hyperthermia, neuroleptic malignant syndrome, serotonin syndrome), endocrine hyperthermia (thyrotoxicosis, pheochromocytoma, sympathoadrenal crisis). In these cases, the body temperature rises to 41 °C or higher, and traditional antipyretic pharmacotherapy is usually ineffective.

Fevers are classified according to two principles: infectious and non-infectious; out-of-hospital and in-hospital (48 hours or later after admission to the hospital). Such patients are characterized by less significant rises in body temperature, and traditional pharmacotherapy is very effective in this case.

Thus, when the neurons of the thermoregulation center, as well as the associated zones of the cortex and trunk of the brain, are irritated, which occurs when the corresponding parts of the brain are damaged, according to Russian-language literature, a centrogenic hyperthermic reaction develops (one of the forms of hyperthermic reactions), from the point of view of foreign literature - neurogenic fever , neurogenic fever (non-infectious fever).

The effect of elevated body temperature on neurocritical care patients

It has been proven that hyperthermic conditions occur more often in intensive care patients with acute brain injury, compared to patients in intensive care units general profile. It has also been suggested that fever in general intensive care unit patients may be a beneficial response to infection, and aggressive temperature reduction may not only not be indicated, but may also be associated with an increased risk of developing fatal outcome.

One such study demonstrated that the use of antipyretics medicines increased mortality in patients with sepsis, but not in non-infectious patients. In a controlled randomized trial, 82 patients with various injuries(with the exception of TBI) and body temperature > 38.5 ° C were divided into two groups: one received “aggressive” antipyretic therapy (650 mg of acetaminophen (paracetamol) every 6 hours at body temperature > 38.5 ° C and physical cooling at body temperature > 39.5 ° C), others - “permissive” (therapy began only at body temperature > 40 ° C, acetaminophen was administered, and physical cooling was carried out until the temperature reached below 40 ° C). The study was stopped when the mortality rate in the aggressive therapy group was 7 to one in the permissive therapy group.

However, there is compelling evidence that in patients with brain damage, the hyperthermic response increases the likelihood of death. It has been shown that mortality increases in patients with TBI, stroke, if they have an elevated body temperature in the first 24 hours from the moment of admission to the critical care unit; but in patients with central nervous system (CNS) infection, no such pattern was found.

Another study examined 390 patients with acute cerebral circulation, the relationship between high body temperature and mortality, the degree of neurological deficit in survivors and the size of the lesion in the brain was analyzed. It turned out that for every 1 °C increase in body temperature, the relative risk of an unfavorable outcome (including death) increases by 2.2 times, and a hyperthermic state is also associated with a large size of the lesion of the brain.

Of 580 patients with subarachnoid hemorrhage (SAH), 54% had elevated temperature bodies and showed worse disease outcomes. A meta-analysis of 14,431 clinical records of patients with acute brain injury (primarily stroke) associated elevated body temperature with worse outcome for each outcome measure. Finally, an analysis of 7,145 medical records of patients with TBI (of which 1,626 were with severe TBI) showed that the likelihood of an adverse outcome (including death) on the Glasgow Outcome Scale was higher in patients who had an elevated body temperature in the first three days stay in the intensive care unit, moreover, the duration of fever and its degree directly affects the outcome.

There are several possible explanations for why hyperthermic conditions increase mortality specifically in patients with brain damage. It is known that the temperature of the brain is not only slightly higher than the internal body temperature, but the difference between them increases as the latter increases. Hyperthermia increases metabolic demands (a 1°C increase in temperature results in a 13% increase in metabolic rate), which is detrimental to ischemic neurons.

An increase in GM temperature is accompanied by an increase intracranial pressure. Hyperthermia increases swelling and inflammation in damaged brain tissue. Other possible mechanisms of brain damage: disruption of the integrity of the blood-brain barrier, disruption of the stability of protein structures and their functional activity. Assessing metabolism in 18 patients with SAH during hyperthermia and induced normothermia, they found a decrease in the lactate/pyruvate ratio and fewer cases where lactate/pyruvate > 40 (“metabolic crisis”) in patients with normal temperature bodies.

Considering the effect of elevated temperature on the damaged brain, it is very important to quickly and accurately determine the etiology of the hyperthermic state and begin correct treatment. Of course, if there is evidence, the appropriate antibacterial drugs- life-saving means. However, early and accurate diagnosis centrogenic hyperthermia may prevent patients from prescribing unnecessary antibiotics and complications associated with their use.

Hyperthermic conditions in neurosurgical intensive care units

According to Badjatia N. (2009), 70% of patients with damage to the brain have an elevated body temperature during their stay in intensive care, and, for example, among patients in general intensive care units - only 30-45%. Moreover, only half of the cases had fever ( infectious cause). Among patients in neurosurgical intensive care units (ICU), patients with SAH had the greatest risk of developing a hyperthermic state, both fever (infectious genesis) and a centrogenic hyperthermic reaction (non-infectious genesis).

Other risk factors for centrogenic hyperthermia are ventricular catheterization and length of ICU stay. Of 428 patients in the neurosurgical ICU, 93% with a hospital stay > 14 days had an elevated temperature, and 59% of patients with SAH also experienced increases in body temperature above febrile levels. In turn, among patients with SAH, the greatest risk of developing a hyperthermic reaction was in patients with a high grade on the Hunt & Hess scale, with intraventricular hemorrhage and a large aneurysm size.

Fever of non-infectious origin

Not all patients with high body temperature have an infectious etiology as the cause of fever. Among neurosurgical ICU patients, only 50% of fever cases have an infectious cause. In general intensive care units, the most common cause of non-infectious fever is the so-called postoperative fever.

Other possible non-infectious causes of fever: drugs, venous thromboembolism, non-calculous cholecystitis. Almost any drug can cause fever, but the most commonly used in ICU settings include antibiotics (especially beta-lactams), anticonvulsants (phenytoin), and barbiturates.

Drug fever remains a diagnosis of exclusion. No characteristic features. In some cases, this fever is accompanied by relative bradycardia, rash, and eosinophilia. There is a temporary relationship between the administration of the drug and the onset of fever or the discontinuation of the drug and the disappearance of the fever. Possible mechanisms of development: hypersensitivity reactions, idiosyncratic reactions.

14% of patients diagnosed with pulmonary embolism had a body temperature > 37.8 °C without any other alternative cause, according to the PIOPED (Prospective Investigation of Pulmonary Embolism Diagnosis) study. Fever associated with venous thromboembolism is usually short-lived, with mild elevations in temperature, and resolves after initiation of anticoagulant therapy. Hyperthermia associated with venous thromboembolism is associated with an increased risk of 30-day mortality.

Spontaneous ischemic or inflammatory injury to the gallbladder can also occur in a critically ill patient. Occlusion of the cystic duct, bile stagnation, and secondary infection can lead to gangrene and perforation of the gallbladder. The diagnosis should be suspected in patients with fever, leukocytosis, pain in the right hypochondrium. Ultrasound examination (US) of the gallbladder has a sensitivity and specificity of > 80%, while the diagnostic value of spiral computed tomography (SCT) of the gallbladder region is higher.

Centrogenic hyperthermic reaction

Even after a thorough examination, the etiology of fever will not be established in some patients. The genesis of elevated temperature in 29% of neurological ICU patients remains a mystery. Thus, according to Oliveira-Filho J., Ezzeddine M.A. et al. (2001), among 92 examined patients with SAH, 38 had febrile temperature, and in 10 (26%) of them an infectious source of fever was not detected. Among patients with TBI, 4-37% experience centrogenic hyperthermia (after excluding other causes).

The pathogenesis of centrogenic hyperthermia is not fully understood. Damage to the hypothalamus with corresponding increases in PgE levels underlies the origin of centrogenic hyperthermia. A study in rabbits showed hyperthermia and increased level PgE in cerebrospinal fluid (CSF) after hemoglobin injection into the ventricles of the brain. This correlates with many clinical observations in which intraventricular blood is a risk factor for the development of non-infectious fever.

Centrogenic hyperthermic reactions also tend to occur early in the course of treatment, thereby confirming the fact that the initial injury is centrogenic. Among patients with TBI, patients with diffuse axonal injury (DAI) and frontal lobes are at risk for developing centrogenic hyperthermia. Damage to the hypothalamus is likely associated with these types of TBI. A cadaveric study showed that hypothalamic damage occurs in 42.5% of cases of TBI associated with hyperthermia.

It is also believed that one of the causes of centrogenic hyperthermia may be the so-called imbalance of neurotransmitters and neurohormones involved in thermoregulation processes (norepinephrine, serotonin, dopamine). With dopamine deficiency, persistent centrogenic hyperthermia develops.

A number of studies have been aimed at identifying neurosurgical ICU patient-specific predictors of centrogenic hyperthermia. One such predictor is the time of fever onset. For non-infectious fevers, the typical appearance is early stages hospitalization of the patient in the ICU.

Thus, one study showed that the occurrence of hyperthermia in the first 72 hours of hospitalization, along with SAH, are the main predictors of the non-infectious etiology of fever. A study of 526 patients found that SAH and intraventricular hemorrhage (IVH) caused hyperthermia within 72 hours of intensive care admission. a long period fevers are predictors of centrogenic hyperthermia. Another study associated prolonged ICU stay, ventricular ventricular catheterization, and SAH with noninfectious etiologies of fever. The authors of the study came to the conclusion that blood in the ventricles is still a risk factor, since catheterization of the ventricles of the brain often occurs with intraventricular hemorrhage.

Differential diagnosis

The ability to differentiate between infectious and noninfectious causes of fever is critical in the treatment of neurological ICU patients. A thorough examination should be carried out to identify the infectious source. If the risk of infection is high or the patient is unstable, antibiotic therapy should be started immediately.

One of the possible tools for identifying the infectious nature of fever is serum biomarkers of infection. Procalcitonin, one such marker, has been widely studied as an indicator of sepsis. A 2007 meta-analysis (based on 18 studies) found the sensitivity and specificity of the procalcitonin test to be >71%.

Duration of antibiotic therapy started after positive result procalcitonin test should theoretically decrease. Thus, a recent meta-analysis of 1,075 case reports (7 studies) showed that antibiotic therapy initiated after a positive procalcitonin test does not affect mortality, but the duration of antibiotic therapy is significantly reduced.

Also, to differentiate between centrogenic hyperthermia and infectious-inflammatory fever, a sign such as slight (< 0,5 °С) разница между базальной и периферической температурами - изотермия. Для ее выявления производится термометрия в трех разных точках (аксиллярно и ректально).

An interesting clinical observation is that extremely high body temperature (> 41.1 °C) that occurs in patients in neurosurgical intensive care units, as a rule, has a non-infectious etiology and can be a manifestation of a centrogenic hyperthermic reaction, malignant hyperthermia, malignant neuroleptic syndrome, drug fever. In addition to testing for infectious causes of fever, drug-induced hyperthermia should also be excluded.

The ratio of temperature to heart rate may be an important criterion differential diagnosis hyperthermic states. Typically, heart rate increases as body temperature increases (for every 1°C increase in body temperature, heart rate increases by approximately 10 beats/min). If the pulse rate is lower than predicted at a given temperature (> 38.9 °C), then relative bradycardia occurs, unless the patient is receiving beta blockers, verapamil, diltiazem, or has a pacemaker.

Considering these exclusion criteria, relative bradycardia in neurosurgical intensive care unit patients with hyperthermia (with a high degree of probability) indicates its non-infectious origin, in particular, a centrogenic hyperthermic reaction or drug fever. In addition, only in rare cases, relative bradycardia is observed in patients with a fever in general intensive care units against the background of developed nosocomial pneumonia, ventilator-associated pneumonia as a result of an outbreak of nosocomial legionellosis.

Drug fever occurs in approximately 10% of intensive care unit patients. Moreover, its occurrence does not exclude the possibility of development infectious disease or other condition accompanied by hyperthermia. Classically, such patients look “relatively well” for their temperature readings. Patients with drug fever invariably exhibit relative bradycardia, but if the body temperature is< 38,9 °С, то дефицит пульса может быть не так очевиден.

Laboratory tests in such patients will show unexplained leukocytosis with a shift to the left (mock infectious process), eosinophilia, increased ESR, but blood culture for sterility will not reveal signs of infectious genesis of hyperthermia; the levels of aminotransferases and immunoglobulin E may also slightly increase. As a rule, such patients are burdened allergy history, in particular, medicinal.

A very common misconception is that a patient cannot develop drug fever to a drug that he has been taking for a long time, and if such reactions have not previously occurred to it. In most cases, it turns out that the cause of such a fever is precisely the drug that the patient has been taking for a long time.

If the patient continues to have a fever despite taking antibiotics, or the microbial source is not found, screening for venous thrombosis- both clinical and instrumental (ultrasound of the veins of the upper and lower limbs). Atelectasis has often been cited as a cause of non-infectious fevers, but the few studies that have been done have not found any pattern. Non-calculous cholecystitis can be a life-threatening condition, given the very vague symptoms in patients in a coma. Ultrasound abdominal cavity should help in diagnosis.

Only after careful exclusion of infection and the above-mentioned non-infectious causes of fever in neurological intensive care units can a diagnosis of centrogenic hyperthermia be made. As already mentioned, some nosologies are more predisposing to the development of centrogenic hyperthermia.

Aneurysmal SAH is the most significant risk factor, followed by IVH. Among patients with TBI, patients with DAP and damage to the frontal lobes are at risk for the development of hyperthermia. Continued fever despite treatment and its occurrence within the first 72 hours of admission to the ICU also indicates centrogenic hyperthermia. Centrogenic hyperthermia may not be accompanied by tachycardia and sweating, as is usual with infectious fever, and may be resistant to antipyretics.

Thus, the diagnosis of “centrogenic hyperthermic reaction” is a diagnosis of exclusion. Although it is advisable to avoid prescribing antibiotics without indications due to the development of undesirable side effects, refusal antibacterial therapy may be fatal in patients with sepsis.

Therapeutic options

Since fever is caused by a prostaglandin-induced shift in the hypothalamic set point, appropriate therapy must block this process.

Conventional antipyretic drugs, including paracetamol and nonsteroidal anti-inflammatory drugs (NSAIDs), interfere with prostaglandin synthesis. A number of studies have shown their effectiveness in relieving fever, but they do not affect the mortality rate. Studies have also shown that centrogenic hyperthermic reactions are, to varying degrees, resistant to traditional pharmacological therapy. Only 7% of patients with TBI and 11% of patients with SAH had a decrease in body temperature while taking antipyretics.

There is no generally accepted method for stopping centrogenic hyperthermic reactions. Some medications have been proposed: continuous intravenous infusion of clonidine as part of the so-called neurovegetative stabilization, the use of dopamine receptor agonists - bromocriptine in combination with amantadine, propranolol, continuous infusion of low doses of diclofenac.

Physiotherapeutic methods of therapy have been proposed, in particular, contact exposure to electromagnetic radiation on the area located between the spinous processes of the C7-Th1 vertebrae. One study even showed that decompressive hemicraniectomy for severe TBI helps reduce brain temperature, likely by increasing conductive heat transfer.

In a clinical study involving 18 children aged 1 week to 17 years, most of whom had severe TBI, a 10-15 minute intravenous infusion of cold water was used to quickly relieve hyperthermia. saline solution(4 °C) in an average volume of 18 ml/kg. The authors concluded that this technique is safe and effective. Similar studies were conducted in adult patients with severe TBI and also showed their effectiveness.

Physical cooling is used when drug therapy insufficient. Fundamentally everything medical methods Hypothermia can be divided into two categories: invasive and non-invasive. General external cooling can cause muscle tremors, which in turn will reduce the effectiveness of the technique and increase the metabolic needs of the body. To avoid this, deep sedation of the patient may be required, including the use of muscle relaxants.

As an alternative, some studies suggest the use of selective craniocerebral hypothermia, as well as non-invasive intranasal hypothermia, although data from clinical studies conducted in patients with severe TBI are very contradictory, primarily regarding the effectiveness of this method.

Endovascular (invasive) cooling devices have been developed to rapidly induce hypothermia. Comparing the effectiveness and safety of endovascular cooling agents and devices for external hypothermia, it can be noted that today both methods are equally effective for inducing hypothermia; there is no significant difference in the incidence of side effects, mortality, or adverse outcomes in patients. However, external cooling is less accurate during the hypothermia maintenance phase.

Conclusion

Fever is a common symptom among patients in critical care units. The damaged brain is particularly sensitive to hyperthermia, and numerous experimental and clinical studies show an unfavorable outcome in patients with TBI who have elevated body temperature, regardless of its origin. In addition to fever, the cause of a rise in body temperature in patients with acute damage to the brain may be the so-called centrogenic hyperthermia, in other words, the neurological disease itself.

Subarachnoid hemorrhage, intraventricular hemorrhage, and certain types of TBI are risk factors for the development of the latter. Centrogenic hyperthermia is a diagnosis of exclusion, which should be established only after a thorough examination of the patient to identify an infectious or non-infectious cause of fever.

Both fever and centrogenic hyperthermia should be controlled in patients with acute brain injury. To do this, you can use pharmacological antipyretics (effective for fever, to a lesser extent for centrogenic hyperthermia) and physical cooling methods (effective for both fever and centrogenic hyperthermia).

Considering that today there is no generally accepted method for relieving centrogenic hyperthermia, in the future it is necessary to carry out more and better quality clinical studies aimed at identifying effective and safe method relief of centrogenic hyperthermia.

Tokmakov K.A., Gorbacheva S.M., Unzhakov V.V., Gorbachev V.I.