1. Disorders of thermoregulation. Fever. The State Education Institution of Higher Professional Training The First Sechenov Moscow State Medical University under Ministry of Health of the Russian Federation Lecture presentation Professor Pirozhkov S.V. Department of Pathophysiology 2014-2015 education year

2. DISORDERS OF THERMOREGULATION HYPERTHERMIC STATESHYPOTHERMIC STATES HYPERTHERMIA HYPERTHERMIC REACTIONS FEVER HYPOTHERMIA ► Overheating ► Heat stroke ► Sun stroke ► Malignant hyperthermia ► Supercooling

3. Types of hypothermia Core body temperature Mild 32°-35°С Moderate 28°-32°С Severe < 28°C

4. PATHOLOGICAL COSEQUENCIES OF HYPOTHERMIA Decrease in body t° Posterior pituitary Decreased secretion of vasopressin Decreased reabsorption of water and Na+ Dehydration Decrease in systemic BP Haemocon- centration Thrombotic diathesis DIC-syndrome Inhibition of clotting factors activation Poor clotting of blood. Significant blood loss in minor trauma.

5. Fever: ● typical pathological process ● characterized by an increase in body temperature ● caused by the effect of pyrogenic substances ● resulting from an increase in the set point of thermoregulation

6. PYROGENS ENDOGENOUS ЕXOGENOUS Products Products Non-infectious of tissue of hemolysis decay Infectious LPS Lipoteichoic (Gram - -bacteria) acids (Gram + -bacteria)

7. SYMPTOMS THAT ACCOMPANY FEVER ● Backache ● Arthralgias ● Anorexia ● Somnolence ● Chills, rigor (profound chill with piloerection) ● Sweats ● Convulsions ● Changes in psychological status: irritability – delirium – obtundation

8. PATHOGENESIS OF FEVER Neuron of the thermoregulation center cAMP Centers of the sympathetic n.s. Spasm of the skin arterioles Shivering Brain cortex Behavioral response Increase in thermogenesis Preservation of heat Thyroid gland Adrenals

9. STAGES OF FEVER I.The stage of temperature elevation. II.The stage of maintenance of increased body temperature. III.The stage of normalization of body temperature.

10. TYPES OF FEVER according to the extent of the body temperature increase (in the arm pit) Subfebrile < 38°С Febrile 38°С - 39°С Pyretic 39°С - 41°С Hyperpyretic > 41°С

11. TYPES OF FEVER by the pattern of circadian body temperature fluctuation Sustained not exceeding 1°С Remittent 1.5°-2.0°С Intermittent > 2.0°С Hectic (septic) 3.0°-5.0°С

12. Causes of hyperthermia Failure of the heat loss mechanisms under the condition of high environmental temperature Great increase in heat production surpassing the capacity of the heat dissipation mechanisms

13. PATHOGENESIS OF THE SUN/HEAT SHOCK OVERHEATING OF THE HEAD ACCRUING ARTERIAL HYPEREMIAINCREASED FILTRATION OF FLUID IN THE BRAIN TISSUE PROGRESSIVE VENOUS HYPEREMIA COMPRESSION OF THE BRAIN. INCREASED INTRACRANIAL PRESSURE. HYPOXIA. ISCHEMIA. INJURY TO THE NERVOUS CENTERS OF THE BRAIN. DECREASED SYMPATHETIC TONE IN THE PERIPHERAL VESSELS, COLLAPSE SHOCK SEVERE POLYORGANIC INSUFFICIENCY, DEATH