Hypothermia

Question 1

What is the definition of hypothermia?

Answer 1

Core temperature of less than 95F/35C.

Question 2

What are the 4 ways that the body loses heat in a cold environment?

Answer 2

Convection (air/liquid movement over the body)
Radiation (Think the sun)
Conduction (direct contact between surfaces)
Evaporation (sweat/water evaporation)

Question 3

What are the risk factors for hypothermia?

Answer 3

Cold exposure
Cold infusions
Drugs/Toxins
Burns/wounds
Extremes of Age (neonates with large surface area, elderly with lack of normal thermoregulation).
Malnutrition
Endocrine disease

Question 4

What are the temperature ranges for the three stages of hypothermia?

Answer 4

Mild: 90-95F (32-35C) - Fumbles, stumbles, mumbles, grumbles, tumbles.
Moderate: 82-90F (28-32) - shivering stops, stupor, hypotension, dilated pupils, diminished reflexes, AMS
Severe: <82F (<28C) - No response to pain, pulmonary edema, acid base issues, cardiac dysrhythmias, cardiac arrest.

Question 5

What is the difference between active and passive rewarming?

Answer 5

Passive rewarming is exercise, eating, and maintaining ones own body heat including radiated, conductive, convective, and evaporative mechanisms.
Active rewarming is external heat application, drinking/eating warm foods, applying hot water bottles, Hot IV, and skin to skin. Active is usually used for <90F (Moderate-severe hypothermia).

Question 6

At what temperature do you need to start worrying about cardiac irritability from hypothermia, and begin purposeful gentle handling of the victim?

Answer 6

Mod-severe hypothermia, 90F.

Question 7

Name some advanced warming techniques for used in severe hypothermia/hospital treatment.

Answer 7

Extracorporeal Blood Warming: Take blood out and rewarm it before returning it to the body.
Diathermy: radiative heating of the body through low-frequency microwave/ultrasound radiation.
Gastric/colonic/thoracic Lavage: warm fluid irrigation of body spaces to transfer heat, though surface area for heat exchange is very limited.

Question 8

What is the risk for CPR on a severely hypothermic patient?

Answer 8

You could send this patient into ventricular fibrillation if they are not already pulseless/in an abnormal rhythm.

Question 9

What does a patient’s temperature drop after initial rewarming and how does that affect how we attempt rewarming?

Answer 9

Core temperature drops due to return of cold peripheral blood to the core after warming of the periphery. We attempt to warm the core first with exercise, warm fluids taken PO if patient is able.