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cardial instability and/or cardiac arrest require active core

rewarming. Available modalities include warmed isotonic

saline (40°C) lavage of the stomach (only if intubated),

HYPOTHERMIA

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Figure 61-1. ECG demonstrating Osborn J waves (arrow) in a hypothermic patient.

Shivering

mechanisms intact,

no significant

comorbidities

Impaired

thermogenesis or

significant comorbid

ill ness

rewarming

Admission to

telemetry bed

.6. Figure 61-2. Hypothermia diag nostic algorithm.

CHAPTER 61

bladder, and colon. Peritoneal and pleural irrigation can also

be performed after the insertion of percutaneous catheters.

Emergent thoracotomy with internal cardiac massage and

mediastinal irrigation with warmed saline is a very invasive

technique, but has been used successfully in severely

hypothermic patients with prolonged cardiac arrest. When

available, extracorporeal rewarming with cardiopulmonary

bypass remains the most rapid way (>9°C/hr) to rewarm a

patient with severe symptomatic hypothermia.

Patients with ventricular fibrillation and core temperatures <30°C are often resistant to defibrillation. If the initial

attempt at defibrillation is unsuccessful, begin cardiopulmonary resuscitation and actively rewarm the patient to at least

30°C before reattempting. Standard Advance Cardiac Life

Support medications (eg, atropine, lidocaine, arniodarone)

are typically ineffective for the management of hypothermiainduced dysrhythrnias. Remember that a patient should not

be pronounced dead until first rewarmed to 32°C.

DISPOSITION

� Admission

Most patients with moderate and severe hypothermia

require hospital admission for active rewarming and continued investigation into the etiology of hypothermia if

not clearly environmental. Admit all patients with evidence

of cardiac instability and those undergoing active core

rewarming to an intensive care unit setting.

� Discharge

Patients without serious comorbidities who present with

mild to moderate hypothermia and successfully undergo

passive rewarming can be safely discharged, provided there

is a warm environment for them to go. To prevent recurrent cold exposure, obtain social work consultation to

arrange placement for undomiciled patients and admit to

the hospital if unsuccessful.

SUGGESTED READING

Bessen HA. Hypothermia. In: Tintinalli JE, Stapczynski JS,

Ma OJ, Cline DM, Cydulka RK, Meckler GD. Tintinalli's

Emergency Medicine: A Comprehensive Study Guide. 7th ed.

New York, NY: McGraw-Hill, 201 1, pp. 1231-1234.

Jurkovich GJ. Environment cold-induced injury. Surg Clin North

Am. 2007;87:247-267.

U1rich AS, Rathlev NK. Hypothermia and localized c old injuries.

Emerg Med Clin North Am. 2004;22:28 1-298.

Vanden Hoek TL, Morrison LJ, Shuster M, Donnino M, Sinz E.

Lavonas EJ, Jeejeebhoy FM, Gabrielli. Part 12: Cardiac Arrest in

Special Situations: 20 10 American Heart Association Guidelines

for Cardiopulmonary Resuscitation and Emergency

Cardiovascular Care. Circulation. 2010;122:S829-S861.

Wira CR, Becker JU, Martin G, Donnino MW. Anti-arrhythmic

and vasopressor medications for the treatment of ventricular

fibrillation in severe hypothermia: A systematic review of the

literature. Resuscitation. 2008;78:2 1-29.

Cold-Induced

Tissue Inj u ries

Christine R. Stehman, MD

Key Points

• Address hypothermia, dehydration, and any alternative life threats before focusing on cold-ind uced tissue

injuries.

• When in doubt, treat all cold-induced tissue injuries as

frostbite.

INTRODUCTION

Previously the domain of military physicians, the prevalence

of cold-induced tissue injuries in the civilian population has

increased substantially over the past 20 years as a result of

the growth of homelessness and an expanding interest in

cold weather outdoor activities such as skiing and mountain

climbing. Cold-induced tissue injuries are typically divided

into 2 categories: nonfreezing cold injuries (NFCI) and

frostbite. Examples of NFCis include frostnip, chilblains/

pernio, and immersion/trench foot. Of the 2 types of injury,

frostbite is the more devastating and requires more aggressive treatment. That said, chilblains and immersion foot can

also progress to significant disability and require prompt

recognition and intervention.

Although individuals at the extremes of age are at a

higher risk for cold-induced tissue injuries, frostbite is

fairly uncommon in these cohorts. In fact, adults aged

30-49 are the most likely group to suffer frostbite. The

hands and feet account for more than 90% of all reported

frostbite injuries, whereas almost all NFCis involve the feet.

Other areas of the body at risk for cold-induced tissue

injury include the face (eg, nose, ears), buttocks and

perineum, and penis.

There are 3 major categories of risk factors for coldinduced tissue injury. Behavioral risk factors include

• Rewarm frostbitten extremities rapidly in a warm water

bath (4D-42°C) and nonfreezing injuries slowly in a dry

environment.

• Do not discharge patients with cold-induced tissue injuries

without first ensuring they have a warm, dry place to go.

homelessness, inadequate clothing or shelter, alcohol or

drug use/intoxication, and psychiatric illness. Physiologic

risk factors include comorbid diseases that impair distal

circulation ( eg, diabetes, vasculitis), the use of vasoconstric ­