1. Hypothermia Hyperthermia Dr. Stella Yiu Staff Emergency Physician S Yiu, 2012

2. Hypothermia: LMCC wants you to List causes List illnesses that precipitate hypothermia Conduct neurological, CVS and resp assessment List and monitor investigations Manage a hypothermic patient by contrasting different warming methods

3. NORMAL TEMPERATURE: 36.5 – 37.5 CELSIUS

4. Causes 1.Decreased heat production 2.Increased heat loss 3.Impaired thermoregulation

5. 1. Decreased heat production Not enough fuel (poor nutrition, hypoglycemia) Engine slower (hypothyroid, hypopituitarism, adrenal insufficiency) Engine unable to produce heat (age, impaired shivering)

6. Photo credit: RaGardner4 and Pedro J Perrieira,, flickr creative commons 2. Increased heat loss Immersion/exposure

7. 2. Increased heat loss Vasodilation: drugs, alcohol, sepsis, toxins

8. 2. Increased heat loss Skin disorders (burn, dermatitis) Iatrogenic (trauma bay, 3 L cold NS)

9. 3. Impaired thermoregulation Central Metabolic (Cirrhosis, uremia), drugs (barbituates, TCAs), CNS (stroke, trauma, MS, Parkinson) Peripheral Spinal cord transection, neuropathy, DM

10. Physiological effects Pacemaker cells slllllooooow Cardiovascular: Bradycarida, arrhythmia, VF, asytole (<28) Neurologic: depression, activity abnormal less than 33,

11. Examination 35-32 – Mild Physiological adjustment 32-29– Mod CNS: Ataxia Confusion CVS: Brady, Afib < 29: Severe CNS: Coma, fixed pupils CVS: VF, asystole

12. Investigations Temp: esophageal Lytes (HyperK) Coag profile (DIC) EKG

13. Osborn J waves

14. Mild: Passive Rewarming >30 and no CVS - Surface rewarming -Warm blankets -Removal or cold, wet clothing

15. Severe: Arrhythmia VF: CPR, defib, If first defib does not work, do not defib (continue CPR) until warmed to >30 Patient not dead until warm and dead

16. Severe: Active rewarming Gently handle, no CPR on frozen chest Airway: Intubate Breathing: Warm Oxygen Circulation: Warm saline (heated to 65)

17. Severe: Active rewarming Inhalation Intravenous GI lavage Bladder lavage Peritoneal Pleural ECMO Dialysis Invasive

18. NOT DEAD UNTIL WARM (>30-32) AND DEAD

19. Hyeprthermia

20. Hyperthermia: LMCC wants you to List causes List illnesses that predispose to hyperthermia Know abnormal exams of hyperthermic patients Select investigations Manage hyperthermic patient by various cooling methods Understand how dantrolene works

21. Causes Environment (heat stroke) Decreased heat dissipation Obesity Drugs (anticholinergics, serotonin syndrome, sympathomimetics) Metabolic heat Thyroid, pheochromocytoma Malignant hyperthermia Neuroleptic malignant syndrome Sepsis

22. Examination Heat stroke T> 40 Orthostatic BP, tachycardia, tachypnea CNS: Confusion, cerebellar, cerebral edema

23. NMS/MH Physical NMS (post antipsychotic) or MH (post anesthetic) T>40, autonomic dysfunction, lead-pipe rigidity Motor: Myoclonus, dystonia, dysphagia CNS: confusion, agitation, coma

24. Hyperthemia: Clinical and lab findings CVS: CHF, pulmonary edema, CV collpase Liver: necrosis Rhabdomyolysis DIC

25. Cooling Evaporative: Mist + Face Ice packs Con: shivering, cannot attach electrodes

26. More aggressive cooling Tub immersion Con: Cumbersome GI/Peritoneal lavage Con: Invasive Cardiac bypass Con: Invasive, not readily available

27. STOP COOLING WHEN TEMP < 40

28. Dantrolene Muscle relaxer (interferes with coupling-excitation of skeletal muscle cells) Only effective treatment in MH