Episode 891: Hypothermia

Emergency Medical Minute

Contributor: Taylor Lynch MD

Educational Pearls

• Hypothermia is defined as a core body temperature less than 35 degrees Celsius or less than 95 degrees Fahrenheit

• Mild Hypothermia: 32-35 degrees Celsius

• Presentation: alert, shivering, tachycardic, and cold diuresis

• Management: Passive rewarming i.e. remove wet clothing and cover the patient with blankets or other insulation

• Moderate Hypothermia: 28-32 degrees Celsius

• Presentation: Drowsiness, lack of shivering, bradycardia, hypotension

• Management: Active external rewarming

• Severe Hypothermia: 24-28 degrees Celsius

• Presentation: Heart block, cardiogenic shock, no shivering

• Management: Active external and internal rewarming

• Less than 24 degrees Celsius

• Presentation: Pulseless, ventricular arrhythmia

• Active External Rewarming

• Warm fluids are insufficient for warming due to a minimal temperature difference (warmed fluids are maintained at 40 degrees vs. a patient at 30 degrees is not a large enough thermodynamic difference)

• External: Bear hugger, warm blankets

• Active Internal Rewarming

• Thoracic lavage (preferably on the patient’s right side)

• Place 2 chest tubes (anteriorly and posteriorly); infuse warm IVF anteriorly and hook up the posterior tube to a Pleur-evac

• Warms the patient 3-6 Celsius per hour

• Bladder lavage

• Continuous bladder irrigation with 3-way foley or 300 cc warm fluid

• Less effective than thoracic lavage due to less surface area

• Pulseless patients

• ACLS does not work until patients are rewarmed to 30 degrees

• High-quality CPR until 30 degrees (longest CPR in a hypothermic patient was 6 hours and 30 minutes)

• Give epinephrine once you reach 35 degrees, spaced out every 6 minutes

• ECMO is the best way to warm these patients up (10 degrees per hour)

• Pronouncing death must occur at 32 degrees or must have potassium > 12

References

1. 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care - Part 1: Introduction. Circulation. 2005;112(24 SUPPL.). doi:10.1161/CIRCULATIONAHA.105.166550

2. Brown DJA, Burgger H, Boyd J, Paal P. Accidental Hypothermia. N Engl J Med. 2012;367:1930-1938. doi:10.1136/bmj.2.5543.51-c

3. Dow J, Giesbrecht GG, Danzl DF, et al. Wilderness Medical Society Clinical Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2019 Update. Wilderness Environ Med. 2019;30(4S):S47-S69. doi:10.1016/j.wem.2019.10.002

4. Kjærgaard B, Bach P. Warming of patients with accidental hypothermia using warm water pleural lavage. Resuscitation. 2006;68(2):203-207. doi:10.1016/j.resuscitation.2005.06.019

5. Lott C, Truhlář A, Alfonzo A, et al. European Resuscitation Council Guidelines 2021: Cardiac arrest in special circumstances. Resuscitation. 2021;161:152-219. doi:10.1016/j.resuscitation.2021.02.011

6. Plaisier BR. Thoracic lavage in accidental hypothermia with cardiac arrest - Report of a case and review of the literature. Resuscitation. 2005;66(1):99-104. doi:10.1016/j.resuscitation.2004.12.024

Summarized by Jorge Chalit, OMSII | Edited by Meg Joyce & Jorge Chalit, OMSII