#EMConf: Environmental Hypothermia
Hypothermia is a potentially life threatening condition seen more often in the winter seasons that has a spectrum of signs/symptoms and comes with a myriad of multiorgan dysfunction. It is essential for the EM physician to be cognizant of these and treat appropriately.
Neurological - Altered mental status, poor judgement, ataxia, paradoxical undressing, loss of consciousness. At temperatures <29°C, pupillary reflex is abscent and <23°C corneal reflex is absent, which is not prognostic of brain death.
Cardiac - When temperatures drop <32°C, the myocardium become very irritated and can convert from bradycardia to atrial fibrillation/flutter with slow ventricular repsonse → ventricular fibrillation → asystole. Be careful placing a central line and go femoral as the guidewire alone can be enough to send this patient into a deadly arrhythmia
Metabolic - Cold diuresis often occurs so these patients will be volume down. Resuscitate them with warm fluids. Also check for rhabdomyolysis and possible compartment syndrome with increased CK.
Haematologic - Coagulopathy is profound even at temperatures <34°C. This becomes especially important in trauma. Make sure your patients are warmed to stop the bleeding!
|
Stage |
Symptoms |
Core Temp |
Treatment |
|
Mild (HT I) |
Conscious, shivering |
35-32°C |
Warm environment, warm clothing, blankets, sweet drinks |
|
Moderate (HT II) |
Impaired consciousness (may or may not be shivering) |
<32-28°C |
Active external rewarming (bear hugger, warm fluids) Cardiac monitoring Minimal movement |
|
Severe (HT III) |
Unconscious, vital signs present |
<28°C |
HT II management Plus: airway management, consider ECMO |
|
HT IV |
Vital signs absent |
Cardiac arrest is possible below 32°C, much bigger risk <28°C |
CPR Up to 3 doses of epinephrine and defibrillation |
References:
Brown D. Hypothermia. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8eNew York, NY: McGraw-Hill; 2016. http://accessemergencymedicine.mhmedical.com.ezproxy.rowan.edu/content.a.... Accessed January 03, 2019.