Chilly day, time to review frostbite recommendations….
-Frostbite occurs when tissues freeze (as opposed to non-freezing cold injury such as trench foot)
-Complaints include cold, numbness, clumsiness to affected area
-Severity of injury depends on: temperature, time, wind, wet/dry cold, clothing and comorbidities including vascular disease, mental health, dementia, smoking, alcohol (heat loss through vasodilation)
-Tissue destruction due to cold-mediated cell death, local inflammatory response, tissue ischemia
-90% injury is to hands and feet; also affects ears, nose, cheeks, chin
-traditionally divided into:
- first degree- very superficial injury
- second degree– blisters
- third degree- hemorrhagic blister
- fourth degree- injury down to the bone
-more practical to classify as superficial (1st/2nd degree) or deep (3rd/4th degree)
Prehospital management
- move to warm environment, remove wet clothes
- do not rub area, avoid walking on frostbitten feet. Can worsen damage
- if certain that there will be no refreezing can use warm water or body heat. Refreezing will cause increased damage
Hospital management
- address traumatic injuries, bring core temp >35C before warming frostbitten areas
- remove jewelry, can have significant swelling (at times fasciotomy may be indicated)
- warm fluids IV/PO
- ASA, ibuprofen for pain and lessen inflammatory reaction. Will likely need narcotics as well.
- rewarm 37-39C, ideally in whirlpool bath (can add chlorhexidine or iodine to water), continue until tissue becomes erythematous and pliable (typically 15-30 min)
- current recommendations are to selectively drain clear/cloudy blisters by needle aspiration, especially if they restrict movement. Leave hemorrhagic blisters alone. This is controversial.
- wound care: aloe vera (antiprostaglandin, helps with inflammatory response), protective dressing, padding between digits, elevate, splint if necessary
- consider imaging if more advanced injury. angiography and technecium scan provide the best prognostic information with which to guide therapy
- If patient presents within 24 hours, has no contraindications, and has deep tissue significant injury (possible life-altering amputation), consider TPA. Otherwise, consider on case by case basis
- iloprost associated with better outcomes after 24 hrs and no contraindication to use in trauma, but not available in US currently
- no prophylactic abx, give if signs of infection
- +/- tetanus prophylaxis, why not give it?
- insufficient evidence for hyperbaric oxygen, chemical/surgical sympathectomy
- long-term sequelae mostly due to peripheral neurovascular injury and abnormal sympathetic tone: vasospasm, pain, hyperhidrosis, cold hypersensitivity, alterations in sensation, increased risk for frostbite
References:
Mechem CC, Zafren K. Frostbite. In: UpToDate, Post TW (Ed), UpToDate, Waltham, MA. (Accessed on February 19, 2015.)
Charles Handford, Pauline Buxton, Katie Russell, Caitlin EA Imray, Scott E McIntosh, Luanne Freer, Amalia Cochran, and Christopher HE. Frostbite: a practical approach to hospital management. Extrem Physiol Med. 2014; 3: 7.
