#EMConf: Winter Emergencies
Thu, 12/24/2020 - 9:51am
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Non-freezing cold injuries
Trench Foot
-direct injury to soft tissue from prolonged cooling worsened by wet conditions
-pale, mottled foot, immobile, and anesthetic
-treatment consists of supportive care(keep clean, dry bandage, elevated, warm)
-Prevention: keep warm, change wet socks, ensure good footware
Chilblains / Pernio
-inflammatory lesions due to exposure to damp, non-freezing temperatures for long periods of time
-generally toes, fingers, ears, and lower legs affected
-risk factors: Raynaud’s, SLE, climate
-symptoms can develop hours after exposure: edema, erythema, vesicles, bullae
-supportive care: re-warming, elevation, bandaging
-nifedipine 20mg PO TID possibly effective
Panniculitis
--necrosis(mild) of subcutaneous fat tissue due to prolonged exposure to above-freezing temperatures
-”popsicle panniculitis” in children
Cold Urticaria
-this is a hypersensitivity reaction to cold air or water
-can rarely result in anaphylaxis
-treat with antihistamines
-consider prescribing epinephrine injector upon discharge, PCP and allergist follow-up
Freezing Injuries / Frostbite
Epidemiology and risk factors
-High risk groups: military personnel, drugs/EtOH, homeless, elderly, psychiatric disorders
-generally occurs in men > women
-Temperature: risk of frostbite greatly influenced by temperature but also wind chill
-Risk of frostbite <5% when temperature is above 5F, and most often occurs below-4F
-Other factors that may increase risk: PAD, DM, Raynaud’s, meds(vasoconstrictors)
Classification
-Classified as 1st – 4th degree
-First degree(frostnip): Pallor, erythema, mild edema, and numbness
-Second degree: blistering with edema and erythema
-Third degree: hemorrhagic blistering with tissue loss involving entire thickness of skin
-Fourth degree: tissue loss of deep structures, resulting in loss of body part
Diagnosis and Management
-Clinical diagnosis: history and exam most useful
-no specific labs or imaging necessary
-manage concomitant cold injury, dehydration, hypothermia
-rapid rewarming as soon as possible! Place injured part in warm water 37-39C for ~30 minutes or until area is erythematous / pliable
-treat with IV pain medication and expect severe pain
-no indication to debride blisters or soft tissues in the ED / acute setting
-update tetanus status as frostbite is a tetanus-prone wound
-local wound care with topical aloe vera cream
-antibiotics prophylactically? Controversial, IV penicillin vs topical bacitracin
Disposition
-can consider discharging patients with mild local frostbite if have safe social circumstances
-follow up with burn surgery or plastic surgery
References:
Tintinalli, J. E., Stapczynski, J. S., Ma, O. J., Yealy, D. M., Meckler, G. D., & Cline, D.(2016).Tintinalli's emergency medicine: A comprehensive study guide(Eighth edition.). New York: McGraw-Hill Education.