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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.