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STATE OF ALASKA COLD INJURIES AND COLD WATER
NEAR DROWNING GUIDELINES (Rev 01/2005)
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TRANSPORT
GUIDELINES
SEVERELY HYPOTHERMIC PATIENTS
State of Alaska Cold Injuries Guidelines (see note at
end of this article)
GENERAL PRINCIPLES
1. Hypothermia provides some temporary protection from the effects of
cardiopulmonary arrest and prolongs the possibility of normal recovery with or
without the use of BLS/ALS treatment procedures. The duration of this
protective effect is unknown and treatment procedures in the field should
generally not cause significant delay in evacuation to definitive rewarming
and effective resuscitation.
2. Because of the protective effect of severe hypothermia, resuscitation
efforts should not be discontinued according to the same time criteria used
for normothermic patients.
3. Severe hypothermia causes cardiac instability. Physical stimuli
(includes jostling, exercise, chest compression, and endotracheal intubation)
can cause ventricular fibrillation in a cold heart that is functioning
effectively.
4. Because the severely hypothermic heart is unstable and ventricular
fibrillation can be induced by physical stimuli, it is important to accurately
determine that functional cardiac activity is absent before beginning chest
compression. In severe hypothermia, functional cardiac activity can be present
but the pulse might not be palpable under field conditions because: a. pulse
rate can be very slow; b. pulse pressure is usually reduced in severe
hypothermia; and c. environmental conditions can make even a strong pulse
difficult to feel
5. Cardiac tissue in severe hypothermics is resistant to defibrillation and
anti-dysrhythmia medications. Use of anti-dysrhythmia agents before rewarming
can cause significant accumulation which can have toxic or harmful effects
when the victim is rewarmed. These procedures can be harmful and are generally
withheld until core temperature has been raised to at least 86° F.
ASSESSMENT
1. In order to avoid the possibility of causing ventricular fibrillation in
a cold but functioning heart, take up to 45 seconds to feel for the presence
of a carotid pulse. If no other clinical signs of life are present, the
absence of a palpable pulse usually indicates the absence of functional
cardiac activity.
2. Even if a pulse is not palpable in the field, functional cardiac
activity is always considered to be present in the severely hypothermic
patient if any of the following clinical signs of life are present: a.
spontaneous ventilation; b. response to positive pressure ventilation; c. any
spontaneous movement or sound; d. organized rhythm on cardiac monitor; or e.
audible heartbeat on auscultation.
TREATMENT
1. BLS/ALS procedures in the field have no significant positive effect on
normal recovery and should not be initiated in the field if: a. core
temperature is less than 60° F (15° C). b. chest is frozen/non-compliant. c.
victim has been submersed in water more than 1 hour. d. obvious lethal injury
is present (see page 15). e. these procedures significantly delay evacuation
to controlled rewarming. f. these procedures put rescuers at risk.
2. Ventilation is generally safe and can be effective
even for a prolonged time period. Use oxygen, heat, and humidity as possible.
Indications for the use of endotracheal or nasotracheal intubation are
generally the same whether the patient is normothermic or hypothermic,
although insertion can be more difficult in hypothermics.
3. Chest compression should never be done if any clinical sign of life
(e.g. clinical sign of functional cardiac activity) is present even if a pulse
is not palpable under field conditions.
4. Chest compression should be done in severe hypothermia if functional
cardiac activity is absent. If the patient has not developed a spontaneous
pulse or respirations or other signs of life as stated above and basic life
support has been performed for at least 60 minutes in
conjunction with rewarming techniques, as described in the current State of
Alaska Cold Injuries Guidelines (see note at end of this article), the
EMT may terminate resuscitation efforts. If advanced life support has been
performed for at least 60 minutes and there is no functional cardiac activity
then the EMT may terminate resuscitation efforts.
5. Defibrillation and anti-dysrhythmia medications should not be used
unless core temperature has been raised to at least 86° F. Administration of
one set of shocks is reasonable if the core temperature is unknown.
6. BLS/ALS procedures should be discontinued in the field if: a. rescuers
are exhausted or these procedures put rescuers at risk; or b. these procedures
significantly delay evacuation to controlled rewarming.
7. It is possible that BLS/ALS procedures can be effective in severe
hypothermia even if they only can be used intermittently during evacuation.
These procedures can be discontinued during a technically difficult or
dangerous phase of an evacuation, and restarted when evacuation conditions
permit.
Alternate:
The "metabolic icebox" effect of severe hypothermia can be
temporarily protective and can result in normal recovery with or without other
field treatment, if aggressive controlled rewarming is
initiated soon enough. The time of protection is unknown. Chest
compression during evacuation produces no certain additional benefit in severe
hypothermia, and, in order to avoid induced ventricular fibrillation and to
avoid delay in transport, it should not be used during field evacuation. Use of
ventilation is appropriate if it does not significantly delay transport to
rewarming.
NOTE: Rewarming techniques, as
described in the current
State of Alaska Cold Injuries Guidelines (Revised 1/2005)
Oxygen should be administered, if available. Oxygen
should be heated to a maximum of 108°F (42°C) and humidified if possible.
Heating oxygen without humidification is not an effective warming technique.
IVs should be heated to approximately 104° - 108° F
(40o- 42° C), when possible, but should be no colder than the patient's core
temperature.
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