Advanced Trauma Life Support ATLS Student Course Manual 2018

267
APPENDIX B n Hypothermia and Heat Injuries
Ventricular fibrillation becomes increasingly common
as the temperature falls below 28°C (82.4°F) and at
temperatures below 25°C (77°F), asystole can occur.
Cardiac drugs and defibrillation are not usually effective
in the presence of acidosis, hypoxia, and hypothermia.
In general, postpone these treatment methods until
the patient is warmed to at least 28°C (82.4°F). Given
the high potential for cardiac irritability, large-bore
peripheral IVs—or if necessary, femoral central lines—
are preferred for access. When subclavian or internal
jugular routes are used, do not advance the wire into
the heart. Administer 100% oxygen while the patient
is being rewarmed. Do not let attempts to actively
rewarm the patient delay his or her transfer to a critical
care setting.
Management
The trauma teams’ immediate attention should be
focused on addressing the ABCDEs, including initiating
cardiopulmonary resuscitation (CPR) and establishing
intravenous access if the patient is in cardiopulmonary
arrest. Prevent heat loss by removing the patient from
the cold environment and replacing wet, cold clothing
with warm blankets. Administer oxygen via a bagreservoir
device. Use the proper rewarming technique as
determined by the core temperature, clinical condition
of the patient, available techniques, and experience of
the trauma team (n TABLE B-2).
Mild hypothermia is usually treated with noninvasive,
passive external rewarming. Repeat temperature
measurements to identify falling temperatures that
may require escalation of the warming technique.
Moderate hypothermia can be treated with passive
external rewarming in a warm room using warm
blankets, ambient overhead heaters, warmed forcedair
blankets, and warmed intravenous fluids. Severe
hypothermia may require active core rewarming
methods. Provide humidified and warmed air through
mechanical ventilation. Warm fluid lavage through
a bladder catheter, thoracostomy tube, or peritoneal
dialysis catheter may be effective. Use extracorporealassisted
rewarming in cases of severe hypothermia.
Rapid rewarming is possible with this technique;
rewarming rates of 1.5 to 10 degrees per hour have been
reported. Special equipment and expertise is required.
These patients require close monitoring of their organ
function during the warming process.
n FIGURE B-1 presents an algorithm for warming
strategies for trauma patients after arrival to the
hospital. Warming strategies are escalated based on
degree of hypothermia.
Care must be taken to identify the presence of an
organized cardiac rhythm; if one exists, sufficient
table b-2 rewarming techniques
REWARMING
TECHNIQUE
• Dry patient
• Warm environment
• Shivering
• Blankets or clothing
• Cover head
External
• Heating pad
• Warm water, blankets,
and warm water bottles
• Warm water immersion
• External convection
heaters (lamps and
radiant warmers)
Internal
• Heated intravenous
fluids
• Gastric or colonic lavage
• Peritoneal lavage
• Mediastinal lavage
• Warmed inhalational air
or oxygen
Extracorporeal
Rewarming
• Hemodialysis
• Continuous arteriovenous
rewarming (CAVR)
• Continuous venovenous
rewarming (CVVR)
• Cardiopulmonary
bypass
PASSIVE REWARMING
ACTIVE REWARMING
LEVEL OF
HYPOTHERMIA
Mild (HTI) hypothermia
35°C to 32° C (95-89.6 F)
Mild (HT I) (35°C to 32° C
[95-89.6 F]) and moderate
(HT II) hypothermia < 32°C
to 28° C (< 89.6-82.4 F)
Moderate (HT II) < 32°C to
28° C (< 89.6-82.4 F) and
severe hypothermia (HT III
and IV) < 28°C to < 24°C
(