Advanced Trauma Life Support ATLS Student Course Manual 2018

271
APPENDIX B n Hypothermia and Heat Injuries
personnel or athletes. Do not use this method in
elderly patients because it can increase rather than
decrease mortality. Alternatively, use a commercial
cooling device.
In mass casualty events with classic heat stroke,
the body-cooling unit (BCU) can achieve excellent
cooling rates with improved survival. The BCU
involves spraying patients with water at 15°C (59°F)
and circulating warm air that reaches the skin at 30°C
to 35°C (86°F to 95°F). This technique is well tolerated
and allows for optimal monitoring and resuscitation of
unconscious and hemodynamically unstable patients.
Noninvasive and well-tolerated cooling modalities such
as ice packs, wet gauze sheets, and fans—alone or in
combination—could represent reasonable alternatives
because they are easily applied and readily accessible.
Survival and outcomes in heat stroke are directly
related to the time required to initiate therapy and
cool patients to ≤ 39°C (102.2°F).
Pharmacology
In the case of malignant hyperthermia related
to anesthetic agents or neuroleptic malignant
syndrome, dantrolene (Dantrium, Revonto) reduces
muscle excitation and contraction and decreases core
body temperature. Dantrolene has not been shown
to decrease body temperature when used to treat
heat stroke.
Medications can potentially increase risk of
exertional heat stroke. Examples include but are
not limited to alcohol, any prescription or over-thecounter
stimulant, caffeine or energy drinks, diuretics,
angiotensin converting enzyme converting inhibitors
(especially combined with diuretic), antihistamines,
and anticholinergics. Amphetamines and salicylates
in large doses can elevate the hypothalamic set
point. Antipsychotic medication and antidepressant
medications such as lithium (Lithobid, Lithane)
and selective serotonin reuptake inhibitors can
interfere with thermoregulatory mechanisms. When
possible, obtain a medication history from patient,
family, and/or prehospital personnel. n BOX B-1
lists some medications and drugs that may worsen
heat illnesses.
Prognosis
Factors associated with poor prognosis include
hypotension, the need for endotracheal intubation,
altered coagulation, old age, temperature > 41°C
(105.8°F), long duration of hyperthermia, prolonged
coma, hyperkalemia, and oliguric renal failure.
box b-1 medications and drugs that
may exacerbate heat illnesses
• Alcohol
• Alpha adrenergics
• Amphetamines
• Anticholinergics
• Antihistamines
• Antipsychotics
• Benzodiazepines
• Beta blockers
• Calcium channel blockers
• Clopidogrel (Plavix)
• Cocaine
• Diuretics
• Ecstasy
• Laxatives
• Lithium (Lithobid, Lithane)
• Neuroleptics
• Phenothiazines
• Thyroid agonist
• Tricyclic antidepressants
SummARy
The injuries due to heat and cold exposure are not
only burns or frostbite, but can result in systemic
alterations in temperature regulation and homeostasis.
It is important to understand the etiology and treatment
of exposure injuries.
Bibliography
Cold Injuries
1. Avellanasa ML, Ricart A, Botella J, et al.
Management of severe accidental hypothermia.
Med Intensiva 2012;36:200–212.
2. Brown DJA, Brugger H, Boyd J, Paal P. Accidental
hypothermia. New England Journal of Medicine
2012; 367: 193-8.
3. Castellani JW, Young AJ, Ducharme MB, et
al. American College of Sports Medicine
position stand: prevention of cold injuries
during exercise. [Review]. Med Sci Sports Exer
2006;38(11):2012–2029.
4. Dunne B, Christou E, Duff O, et al.
Extracorporeal-assisted rewarming in the
management of accidental deep hypothermic
cardiac arrest: a systematic review of the
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