Hyperthermia

1. Hyperthermia Zhang Yinglan MD,  Associate chief physicianEmergency DepartmentLonghua Hospital Affiliated Shanghai University of TCM

2. What is hyperthermia? It is an acute heat injury disease resulting from prolonged exposure to high environmental temperature which causes a dysfunction of the temperature-regulating mechanismand excessive loss of water-electrolyte of the body.

3. Causitive Factors • high temperature climate • dry-heat working condition and high humid-warm environment • dysfunction of the temperature-regulating mechanism • increased heat production • poor heat adaptation • impedient heat dissipation

4. Causitive Factors High temperature condition temperature＞32℃ humidity＞ 60％ poor ventilation Long time or high-intensitive work

5. Etiological Factors Obtain excessive external heat Increased heat production Iimpedient heat dissipation Dysfunction of the sweat gland Severe potassium deficiency

6. pathogenesis

7. Heat production Oxidative metabolism Muscle contraction

8. Heat dissipation(15-25℃) Radiation 60% Evaporation 25% Convection 12% Conduction 3%

9. the major way of heat dissipation • depends on the difference between the body surface and environmental temperature（ 15-25℃ →60％， 33℃ →0% ） • the most heat dissipation part of the body is head（50%），then hands and feet Convection Conduction • depends on the air flow rates • the conduction power of water is 240 times than the air • 1g water evaporation for 2.4kj（0.58kcal）heat dissipation • more humidity less evaporation Evaporation Radiation Regulation of heat production and dissipation ＆

10. The influence of  hyperthermia on the human body

11. central nervous system • inhibiting effect • inattention • slow in reacting • decreased accuracy and  Coordination of action • dysfunction • delirium、 mania • coma

12. cardiovascular system arrhythmia heart failure decreased cardiac output

13. respiratory system respiratory alkalosis ARDS

14. water-electrolyte metabolism loss of water and sodium and chlorinum  

15. urinary system • reduction in renal blood flow and glomerular filtration rate • proteinuria and cylindruria • rhabdomyolysis（横纹肌溶解） • myoglobinuria（肌红蛋白尿） • acute renal failure

16. Diagnosis Severe heatstroke Mild heatstroke Premonitory heatstroke

17. Prodrome High temperature environment Thirsty、fatigue、excessive sweating、dizziness、headache、palpitation、nausea… The body temperature is about normal or  slightly high

18. Mild Hyperthermia The exacerbation of premonitory hyperthermia The early stage of dysfunction of the circulation：flushed face or pale complexion、 dysphoriaor apathia 、nausea and vomiting 、 sweating 、 clammy skin, 、thin and rapid pulse、 hypotension 、 increased heart rate The body temperature is slightly increased

19. Severe Hyperthermia • heat cramps • heat exhaustion • heat stroke type

20. high temperature sweating a lot excessive loss of water and salinity supply more water but less salinity hyponatremia and  hypochloremia muscle cramp、pain（water loss ＞ salinity loss） heat cramps

21. excessive expansion of peripheral vascular collapse、shock heat  exhaustion

22. body temperature＞42℃ → protein denaturation • body temperature＞50℃ → all cell death a few minutes later • during the autopsy,   pathological change can be seen in the brain、  neurocyte 、  cardiomyocytes、lung、liver、kidney and hemorrhagic spots can be found in the  pleura、 peritoneum 、small intestine，etc heat stroke

23. Clinical symptoms of severe hyperthermia

24. Heat cramps it refers to a severe muscle cramp and contraction pain （the muscle of four limbs and abdomen） it happens at the beginning of the hot season and before the heat adaptation of the body young people who do manual work under the high temperature circumstance and sweat a lot

25. Heat exhaustion acute onset dizziness, headache, suddenly faint , pale complexion ， cold sweat in the skin, weak or slow pulse, hypotension but with normal pulse pressure awake after lie on the back or leave the high temperature environment old people or individuals with heat intolerance

26. Heat stroke typical symptoms：hyperpyrexia , anidrosis , disturbance of consciousness prodrome：fatigue, dizziness, headache, nausea, sweat reduced body temperature increases rapidly（＞41℃） →somnolence, apathy, coma hot and dry skin ，no sweat， flushed or pale skin ， or even cyanosis

27. Heat stroke pulse quicken ， increased pulse pressure ， decreased blood pressure arrhythmia fast and shallow breathing ，Chyne-Stokes respiration muscle twitches pupil contraction ，pupillary light  reflexdisappear

28. Heat stroke shock heat stroke heatfailure arrhythmia pulmonary edema cerebral edema liver and kidney failure ARDS gastrointestinal bleeding DIC…

29. Laboratory examination

30. Heat cramps blood natrium ↓ blood chlorine ↓ ucre urine creatine ↑

31. Heat exhaustion hematocrit (HCT) ↑ hyponatremia 、 hypokalemia 、slight azotemia or abnormal liver function

32. Heat stroke hyperkalemia, hypercalcemia, hemoconcentration, leukocytosis , thrombocytopenia Cr、BUN、AST、ALT、LDH、CPK ↑ proteinuria , cylindruria,myoglobinuria , acidosis EKG

33. Diagnosis

34. Heat cramps or exhaustion exposure history to high temperature environment symptoms：sweata lot, muscle cramps, postural syncope , transient fall of blood pressure laboratory examination

35. Heat stroke • three characteristics • hyperpyrexial fever • dry and hot skin • severe central nervous system symptoms • acute onset • causitive factors

36. Differential diagnosis • diseases cause high fever and coma • cerebral malaria • Japanese encephalitis • meningitis • acute cerebrovascular disease • organic phosphorus pesticide poisoning • …

37. 1 2 3 • causes • duration of the injury • start time of rescue • severity • body temperature • disturbance of •  water and  • electrolyte • consciousness • pulse • respiratory • bloodpressure • muscular tension • urine volume  Evaluation of vital signs evaluate evaluate observation

38. Treatment

39. On-site treatment leave the high temperature environment immediately have a quiet rest in a shelter, loosen the clothing drink some cold salty water NS、GS、KCL ivgtt (for a circulatory failure patient) no massage for the muscle cramp and contraction pain electrolyte supplement a positive rescue for a heat sroke patient

40. Hypothermia therapy

41. lower the temperature of environment cool and ventilated place indoor temperature <20 oC

42. lower the temperature of the body surface rub the body surface  put the ice bag on the main artery(head, bilateral carotid artery, armpit, groin) avoid shivering cold bath

43. lower the temperature of the central body temperature 5％GS 1000～2000mlivgtt (4-10oC) 10％GNS 1000ml enema (4-10oC) inject cold NS into the gastric tube

44. drug hypothermia chlorpromazine 氯丙嗪 naloxone 纳洛酮

45. lower lower the body temperature till 38oC (rectal temperature) • maintain the systolic pressure＞90mmHg

46. a cool and ventilated environment • cold salty drink • Chinese patent medicine（rendan mini-pills， “ 10 drops ”， Huoxiangzhengqi tablets） •  acupoint massage with essential balm（ Taiyang(EX-HN5)，Hegu（L14）） • cold compress， alcohol bath • 5％GNS1000－2000 ml ivgtt Emergency treatment Prodrome mild &

47. 热 痉 挛 在补足体液情况下，仍有四肢肌肉抽搐和痉挛性疼痛，可缓慢静注10%葡萄糖酸钙10ml＋维生素C 0.5。 急救处理

48. 5％GNS2000－3000mlivgtt quickly •  vasopressor（ dopamine，  aramine） maintain the systolic pressure＞90mmHg Emergency treatment circulation collapse

49. Emergency treatment • physical hypothermia • drug hypothermia（chlorpromazine） •  naloxone treatment（naloxone 0.8mg +25% GS20ml iv） • symptomatic and supportive treatment heart stroke

50. prevent from cerebral edema oxygen fluid infusion Emergency treatment ventilation low temperature hypothermia comprehensive and supportive treatment