1. HYPOTHERMIA n Dr. Josep Vidal Alaball

2. “No previously healthy person should die of hypothermia after he has been rescued and treatment has been started” Cameron C.Bangs, M.D. The Mountaineers 1986

3. DEFINITION DEFINITION n Body temperature < 35ºC with low reading rectal thermometer CAUSES n Exposure to adverse environments: wet and windy conditions n Immersion in cold water Risk increases by drug/alcohol ingestion, illness or injury. Elderly & very young: more susceptible.

4. ACTIONS TO ALL DE PATIENTS n A B C n Remove wet clothing n Patient dried and covered with blankets or insulating equipment n Maintain horizontal position n Avoid rough movement and excess activity n Monitor core temperature and cardiac rhythm.

5. ASSESS RESPONSIVENESS, BREATHING AND PULSE Pulse/Breathing absent: Start CPR Pulse/Breathing present: Rewarming

6. 34ºC - 36ºC (mild hypothermia) 34ºC - 36ºC (mild hypothermia) n Passive rewarming n Active external rewarming 30ºC - 34ºC (moderate hypothermia) 30ºC - 34ºC (moderate hypothermia) n Passive rewarming n Active external rewarming of truncal areas only < 30ºC (severe hypothermia) < 30ºC (severe hypothermia) n Active internal rewarming WHAT IS CORE TEMPERATURE ?

7. REWARMING n PASSIVE REWARMING –Blankets, insulating equipment n ACTIVE EXTERNAL REWARMING –Heated blankets –Warm bath (up to 40ºC) n ACTIVE INTERNAL REWARMING –Warm, humidified oxygen –Warm i.v. fluids –Gastric, peritoneal or pleural lavage with warm fluids (at 40ºC) –Blood rewarming by haemodialysis or cardiopulmonary bypass.

8. DECISION TO RESUSCITATE n Beware of pronouncing death in patients with hypothermia! n Death should not be confirmed until patient has warmed to a temperature > 33ºC, or attempts to raise core temperature have failed. n Cold itself may produce a very slow, small volume and irregular pulse with unrecordable BP. n Hypothermia confers a degree of protection to vital organs. Associated arrhythmias are potentially reversible. n Resuscitation has to be prolonged.

9. RESUSCITATION n Open, clear and maintain airway. n If no respiration ventilate with high concentration of warm, humid oxygen. n Pulse can be very slow. Palpate a major artery for a minimum 1 min. n Consider hypothermia as a cause of bradycardia in any casualty.

10. RESUSCITATION n Rates for ventilation and chest compression as for normothermic patient, but hypothermia may cause stiffness of the chest wall. n Cannulate a central or large proximal vein. n Infuse warm N-Saline.

11. ARRHYTHMIAS n As body temperature falls: –Sinus bradycardia –Atrial fibrillation –Ventricular fibrillation –Asystole n Standard treatment protocols should be followed.

12. ARRHYTHMIAS n If core T.< 30º VF may not respond to cardioversion. Rapid core rewarming is necessary with CPR being continued until defib. becomes effective. n Lignocaine no significant effect on VF in hypothermic patients. n Mechanical disturbance ( tracheal intubation, excessively vigorous chest compressions ) can precipitate VF until core T. is raised. n Other arrhythmias tend to revert spontaneously as core T. rises, and usually do no require immediate treatment.

13. INVESTIGATIONS n ABG’s n Electrolyte & glucose n CXRay* n Check for underlying illness or trauma n TFT n Urine output * Stomach should be decompressed with a nasogartric tube to reduce respiratory complications.

14. PROGNOSIS n Neurological recovery still possible after prolonged cardiac arrest, as hypothermia reduces cerebral oxygen requirements. n Prognosis usually determined by severity of underlying illness.

16. THE END