Hypothermia

Hypothermia (as method) - artificial lowering the temperature of the body (or part of body) by cooling. Is used as an independent or a subsidiary remedy. There are local and General hypothermia.
Local hypothermia of the stomach is made with the help of a special apparatus LGI-1 for bleeding ulcers duodenal ulcer, less stomach, erosive gastritis and a number of inflammatory diseases (such as acute pancreatitis). The patient through the esophagus probe is introduced with a thin-walled cylinder shaped stomach. In the container arrives coolant (50% alcohol temperature 4-5 C), constantly circulating through the system. The duration of hypothermia 3-4 hours. At the same time, blood transfusions. Local hypothermia brain is performed using the apparatus "Geoterm", from which a jet of cold water or cooled air flows around the scalp. Used in severe swelling of the brain, trauma, disruption of blood supply to the brain). The duration of hypothermia 2-4 hours; it is shown that simultaneous intravenous infusion of hypertonic solution, plasma. Local hypothermia limbs used as an anaesthetic with amputation in critically ill. Limb, putting the bags of ice, pre put harness (on his hip, shoulder for 2-3 hours; on the lower leg, arm in 1-2 hours).
General hypothermia used for operations that require temporary stop circulation (open - "dry" - the heart, surgery for aortic aneurysm and others). At decrease of body temperature up to 25oC the termination of blood flow for 10-15 minutes, when cooled below 20 degrees for 45 minutes or even more. Hypothermia get the two methods.
1. External cooling (bath temperature 3-5 degrees, obkladyvanii bags with ice machines - gipotermii in the form of spacesuits, consisting of a system of tubes, which circulates cold air). The patient was given endotracheal anesthesia with muscle relaxers , and controlled breathing. When reaching the depth (see Anesthesia) the patient is placed in a cool bath. Control the temperature in the esophagus or rectum special thermometer. For 30-60 minutes, the temperature decreases to 32-30 degrees. The patient is removed from the bath, dried and put on the operating table. Within 30 minutes the temperature continues to drop yourself by 2-5 degrees. The muscular tremor in the beginning of cooling off additional injection relaxant.
After the operation, put a sticker on the wound, the patient is placed in the bath temperature 40-45 degrees and warm up temperature 33-35°, then transferred onto the bed, covered with a blanket. Next, the body temperature rises yourself. Hypothermia reduces the sensitivity of tissues to hypoxia that allows the brain to endure without harm reduction circulation.
General rules of hypothermia with the help of the apparatus or obkladyvaniya bags with ice same.
2. In vitro (norgannon) cooling; blood systems of the tubes away from the vein of the patient in the cooling system, and then pour into a major artery.
Hypothermia below 20 degrees requires artificial blood (see blood Circulation, artificial). The main danger of hypothermia - fibrillation of the heart. The frequency of this complication increases as temperatures drop below 28 degrees. When fibrillation should be defibrillation (see the Revival of the body).

Hypothermia (from the Greek. hypo - is lower, and therme - heat; synonym General cooling) - artificial temperature reduction is achieved under anesthesia, using the physical effects (cold water, ice, cold air and so on). Hypothermia reduces the body's need for oxygen, increases its resistance to hypoxia (see), reduces or even eliminates the risk of temporary ischemia of the brain. Hypothermia is shown in surgical interventions on "dry" heart, during which it off for 10 minutes or longer (ischemia of brain beyond hypothermia is transferred without any dangerous effects only within 3 minutes), with operations that require aortic cross-clamping and off blood flow through the pulmonary artery. In neurosurgery hypothermia used in operations for aneurysms and brain tumors in the brain. Hypothermia has been effective in thyrotoxic crisis. In patients with severe thyrotoxicosis and significant increase in the level of metabolic processes, it is expedient to apply a moderate hypothermia in combination with autonomic blockade and endotracheal anesthesia. Hypothermia is used for large operations in critically ill, compensatory forces are exhausted before surgery (I. S. Zhorov). In the postoperative period hypothermia shown in hypoxic brain edema, intoxications and injuries of the Central nervous system (A. P. Kolesov).
The combination of anaesthesia (see) with hypothermia - a complex, technically challenging kind of combined anesthesia. The risk of severe complications forces to resort to hypothermia only when the danger, due to the severity of the patient or the complexity of the intervention, than the risk associated with hypothermia.
Hypothermia can be the General and local. When local hypothermia by Allen limb cards with a harness, lined with crushed ice (as melting add new). Later 60-150 minimum temperature of cooled tissue drops to 6-8 degrees, which reduces the need them in oxygen and causes an analgesic effect. In elderly patients in a grave condition, the use of local hypothermia with amputations about atherosclerosis or the diabetic gangrene has proved very effective.


In General hypothermia mandatory endotracheal anesthesia, which provides controlled breathing and the use of muscle (see). Changes in the overall cooling are cyclical (phase) nature. 1st phase of hypothermia - "adrenergic" is characterized by the decrease of the temperature of the heart and esophagus to 34 degrees (primary, or light, hypothermia). Under the influence of adrenaline increases arterial and venous pressure, increased heart rate and breathing, increased arteriovenous difference in oxygen content. Marked hyperglycemia, hyperkalemia, increased blood gets hydrocortisone and thyroxine.
2nd phase starts when the temperature drops to 28 degrees (moderate hypothermia). At the end of this phase, there is a significant suppression of all body functions. There are acceplast muscles, the fall of the arterial and venous pressure, heart rate slows to 40 attacks, reduced cardiac output, and arteriovenous difference (arterialization venous blood), reduces intracranial pressure. Endocrine function is suppressed. The patient loses consciousness. The dose of drugs from this time should be reduced even recommend to switch to 100% insufflation oxygen. In this phase, you can disable heart for a period of 10 minutes
Phase 3 of the coming when cooled below 28 degrees, characterized by depletion of endocrine functions of the pituitary gland, thyroid gland and adrenal glands. Acceplast muscle replaced their relaxation. Often fibrillation of the heart, threatening by death, but if you maintain a superficial level of anesthesia, at a temperature not lower than 21 degrees either respiratory or cardiovascular reflexes will not disappear, although it will be gradually declining. T. M. Darbinyan a cooling phase body with 27 20 degrees allocates as intermediate hypothermia.
Deep hypothermia should be considered cooling below 20 degrees, which requires the use of devices extracorporeal circulation. Drew, Keane and Benson (C. E. Drew, G. Keen, D. C. Benazon) proved that when temperature 13o ischemia of the brain is transferred during the 45 minutes followed by full recovery of all functions. S. A. Kolesnikov and TCS. spent cooling to 9-15,6 degrees of cardiac arrest on 7-45 minutes However, clinical experience deep hypothermia is still small. Mortality also has a very high because often the developing syndrome decortication.
The final stage of hypothermia is the period of warming. It must be ensured the dominance of the parish of oxygen to the tissues over its consumption. It is recommended that active slow warm (warm water, warm air, using diathermy and so on) in combination with adequate anesthesia.
In the initial phase of hypothermia, the body temperature descent is responsible trembling, and oxygen consumption is not reduced, but, on the contrary, increases in 2-7 times. To suppress this reaction is successfully used curarization nedepoliarizutmi relaxers, combined with shallow anesthesia. When yeast is recommended intravenous 10-25 mg chlorpromazine and 20 mg of morphine.
Breathing problems arising from hypothermia causes acidosis, and acidosis and hypoxia myocardial provoke fibrillation of the heart. To fight respiratory acidosis recommend hyperventilation. At the onset of atrial most effective defibrillation capacitor discharge (C. A. Negovsky, N. L. Gurvich).
To improve coronary blood circulation, it is advisable to compression of the thoracic aorta (see the Revival of the body).
To achieve hypothermia apply the methods of external cooling, cooling of the body cavities and extracorporeal circulation. Cooling control thermometry in the rectum or the esophagus (special thermometer).
External cooling is achieved by obkladyvanii patient bubbles with ice, by immersion in a bath with water temperature of 3-5°, wrap in a blanket, through which passed through the tubes cold water. For external cooling of the most convenient special refrigerators, for example, the apparatus Avtopiter" (of Swedish origin).
With either method, external cooling should be discontinued when the temperature of the blood circulating through the chilled surface tissues, reduced by 2/3 of cooling: after cooling the temperature continues to drop, and if not to take into account that, its decline will go a given level of hypothermia.
Hypothermia by cooling cavity - washing opened a chest cold water (1954), introduction into the stomach cavity of the cylinder with circulating ice water, and others - have not received sufficient distribution. In vitro cooling of venous blood from a hollow veins enters into the refrigeration system, and then flows back into the body through the femoral artery. A. A. Vishnevsky, and So M. Darbinyan with TCS. developed a method of combined regional perfusion of the brain and heart, which allows to operate on the open heart in conditions of moderate hypothermia during 9-29 minutes Method of regional hypothermia head with the help of external cooling due to the rapidity and convenience were applied in the complex of measures on resuscitation (see the Revival of the body).