[ANZCOR - Guidelines for cold-related injuries](https://www.anzcor.org/home/new-guideline-page-3/guideline-9-3-3-first-aid-management-of-hypothermia-and-cold-related-injuries/) > [!Key Points] > - absence of shivering in moderate-severe hypthermia means body cannot actively re-warm core temp (rectal or IDC) # Severity ## mild - 32-35 deg C - shivering, apath, ataxia, dysarthria,tachycardia ## moderate 29-32 deg - loss of shivering, ALOC, muscular rigidity, **bradycardia**, hypotension - [[Osborn waves]] generally if T < 30 deg C (rosen’s says <32) ![[Pasted image 20240326001722.png| hypothermia osborn (j waves)]] ## severe <29 deg - coma - fixed and dilate dpupils - areflexia - profound bradycardia and hypotension - slow AF may degenerate into VF or asystole ![[Pasted image 20240326001931.jpg| hypothermia 28 deg]] # Rewarming > **if arrest and temp <32** > - Left sided tube thoracostomy and warm saline lavage (warms the blood in heart and great vessels) > - Warm bladder irrigation with 3-way urinary catheter > - Warm IV fluids - one litre of 0.9% NaCl > - As many as possible external/passive rewarming techniques > - Fem-fem cardio pulm bypass if available **Endogenous re-warming** - warm, dry envionrment - warmed IVF **External exogenous re-warming** - hot bath immerson - forced air blankes - ehat packs - body-to-body contact **Core exogenous rewarming** - warmed, humidified inhalation - left pleural cavity lavage - extracorporeal circulation ([[ECMO]] ![[Pasted image 20230702172108.png]] # Other Treatments ## Glucose - body uses glycogen to generate heat by shivering - in mild cases can have orally - in more severe cases, IV dextrose 5% at 200mL/hour - insulin is inactive at temps < 30 deg, so sometimes they have some hyperglycaemia due to loss of insulin activity, but no real need to give insulin until re-warmed ## Cardiovascular and airway - intubate if needed for airway - gentle volume resus - regard sinus bradycardia and AF as physiological arrhythmia’s of hypothermia - Sinus bradycardia — pacing not indicated unless bradycardia persists after rewarming; atropine likely ineffective - slow AF is benign, tx by warming - [[Magnesium]] is preferred antiarrhythmic in hypothermia - hypothermia causes physiological changes which may make **drugs, electrical defibrillation and pacing less effective** or ineffective - *avoid antiarrhythmics* - if temperature is 30- 34C, double the normal dosing intervals of ACLS drugs - Ventricular fibrillation - defibrillation may be ineffective until core body temperature reaches 30C - ​VF may occur spontaneously in hypothermic patients with temperatures < 29C - if no response to standard ALS, defer further attempts at defibrillation and drug administration until core temperature rises above 30C - Transient ventricular arrhythmias are not significant ## arrest - standard ALS - if DC shocks unsuccessful, then others are unlikely to be so until they are warmer - repeat counter shocks with every 1 deg increase in core temperature # ECG - slow atrial fibrillation - extra positive deflection in QRS (J or [[Osborn waves]]) in II, V3-V6 # Related questions ## hypothermia - [ ] 20Q: [Hypothermia](x-devonthink-item://8AAAF35C-CCF4-4157-9551-5B05727AA0CD?page=11) -- [Answer](x-devonthink-item://FDFBA3A1-6207-4204-AB6D-7483D80C5B5C?page=11) - [x] DUPLICATE Q: [Hypothermia](x-devonthink-item://8AAAF35C-CCF4-4157-9551-5B05727AA0CD?page=11) -- [Answer](x-devonthink-item://FDFBA3A1-6207-4204-AB6D-7483D80C5B5C?page=11) - [ ] 21Q: [Hypothermia](x-devonthink-item://5DD7C01C-AB9B-4F0E-9CC4-266700BD94E8?page=10) -- [Answer](x-devonthink-item://7CE81625-E4A6-40C1-BAEB-7E44C75B1E60?page=12) -- [prop](x-devonthink-item://D0A460D5-938B-4002-A684-EFD9189B08C1?page=9) - [ ] 22Q: [Hypothermia](x-devonthink-item://1A2C485F-D4AD-4821-AFF2-452BA753717F?page=56) -- [Answer](x-devonthink-item://FD716379-1A77-4B5B-B257-1154995ECA6E?page=36) -- [prop](x-devonthink-item://1A2C485F-D4AD-4821-AFF2-452BA753717F?page=68) - [ ] 23Q: [Hypothermia](x-devonthink-item://F0498813-9350-484C-AD5B-6FF7C3AE9015?page=38) -- [Answer](x-devonthink-item://A491A3F6-FD6D-492F-BCBE-7F7BAE101EDF?page=42) - [ ] 24Q: [Hypothermia](x-devonthink-item://7FCD3940-4BB4-45FE-86A6-E5707E82D5B5?page=58) -- [Answer](x-devonthink-item://3263A68A-96A6-43EC-985B-43260C3509BF?page=21) ## OSCE - [RMH 2023 - Beach collapse](x-devonthink-item://CF52CD70-BFC7-407E-B0FA-079027D23E62)