Evaluation and Treatment of Hypothermia, Colin K. Grissom, M.D.
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Cardiac drugs are usually ineffective during moderate and severe hypothermia
because of depressed body metabolism. ACLS guidelines recommend withholding any
IV medications if core body temperature is less than 30°C. The prophylactic use of
bretylium, amiodarone, or lidocaine during hypothermia has not been evaluated and is not
recommended.
Rewarming Methods
Rewarming methods can be divided into passive and active modalities. In passive
rewarming the patient is removed from the cold environment and dry insulation is
provided to allow endogenous rewarming through shivering. This is most appropriate for
shivering mildly hypothermic patients. Active rewarming may be separated into external
and internal modalities. Simple active external rewarming modalities, such as hot packs
or hot water bottles may be applied to passively rewarm mildly hypothermic patients if
they are not shivering. Moderate or severe hypothermia requires active external or
internal rewarming techniques and patients should be rapidly transported to an
appropriate hospital for rewarming.
Table 3. Rewarming (comprehensive review in (Giesbrecht 2000))
1)
Passive:
Allows endogenous rewarming by removing the person from the cold
environment, removing wet clothing, providing insulation, and allowing
rewarming by shivering.
2)
Active, External: The application of an external heat source.
Forced air warming (Bair Hugger) (Giesbrecht 1998; Koller 1997)
Arteriovenous anastomoses rewarming (Vanggaard 1999)
Negative pressure rewarming (Grahn 1998)
Warm water immersion (not recommended in the field)
Heating pads
Hot water bottles
Warmed blankets
Radiant heat
3)
Active, Internal:
Inhalation of heated humidified oxygen (adjunctive with other rewarming
methods)
Warm IV Fluids (adjunctive with other rewarming methods)
Body cavity lavage (thoracic, peritoneal, gastric)
Extracorporeal circulation for severe hypothermia with cardiac arrest
(Walpoth 1997)
Rewarming Mild Hypothermia
If vigorous shivering is present, endogenous rewarming should be assisted by
removing the patient from the cold environment, removing wet clothing, and providing
insulation. Warm sugar containing liquids should be given to the conscious patient. The
application of external warmth with heating pads, hot water bottles, or body to body
