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Case Report: A Closer Look At Frostbite Treatment Over One Year
Alaska is commonly known as the Last Frontier. People from all over the world come to Alaska to challenge themselves and to enjoy outdoor activities such as fishing and hunting. However, some get caught unprepared when unforeseen circumstances arise.
One of those circumstances is frostbite, which occurs when water crystallizes within the tissues causing tissue damage and cell death upon being exposed to extreme cold temperatures.1–7 It is important to differentiate between frostnip—superficial cold injury without the ice crystal formation—and frostbite. Frostnip does not cause tissue damage.1,4,5,7
Over the years there were multiple classifications systems that have been used for cold injuries. The Field Classification of Frostbite is practical use outside of the hospital setting. It classifies frostbite into two categories: Superficial frostbite involves superficial tissues and anticipates minimal tissue damage, while deep frostbite corresponds to deeper tissues and tissue loss.1,3,7
Frostbite was classically divided into 4 levels or degrees:1,3,6–8
First degree. Characterized by erythema, numbness, and yellow or white plaque can develop in an injured area
Second degree. Involves superficial blistering with erythema and edema
Third degree. Hemorrhagic blisters indicating deeper injury passed the reticular dermis
Fourth degree. Deep injury involving muscle and bone
Experts currently recommend the Cauchy classification method due to its use in predicting amputation risk.1,6,9 As the Cauchy classification notes, the higher the grade, the higher the risk of amputation and limb loss.6,9
Grade 1. Injury is superficial without blisters.
Grade 2. Involves the distal phalanx with clear blisters.
Grade 3. Involves the intermediate and proximal phalanx with hemorrhagic blisters.
Grade 4. Injury extends to the carpal/tarsal bones with hemorrhagic blisters.
A Closer Look At The Patient Presentation
A 52-year-old male presented to the emergency department with frostbite of bilateral feet. He described multiple episodes of freezing and warming of toes over the previous two- to three-day period. Upon arrival, the patient was wrapped in multiple warm blankets. He had recently moved to Alaska, and was not previously seen by this facility. The patient was living on the streets without adequate shelter or income.
The emergency department physician evaluated the patient and described his injuries as frostbite to bilateral feet extending three to four cm to mid-metatarsal bones with several blisters on the toes. The feet were warm and red without tracking proximally. No drainage or weeping was present. Palpable 2/4 dorsalis pedis and tibialis posterior pulses were present on both feet. The patient was able to move toes on command, but he was unable to feel them.
The patient’s vital signs were within normal limits with a temperature of 98.5ºF. His past medical history was unremarkable. Social history was positive for tobacco, one pack per week. He denied use of alcohol or illicit drugs.
The patient’s emergency department treatment entailed:
1. Passive rewarming
2. Intravenous fluids of 1 L normal saline
3. Laboratories were normal except; WBC 13, AST 103 and Glucose 157
4. Ibuprofen
5. Antibiotics were considered, but not administered
6. Tetanus prophylaxis
7. Application of sterile dressing, Bacitracin ointment, Xeroform and Kerlix to feet
8. Admitted to hospital
9. Consult for orthopedics/podiatry/wound care the following morning
On admission, the admitting physician determined that the injury had occurred three days prior to admission, so the patient was outside the recommended window for a tissue plasminogen activator (TPA) as well as prostacyclin treatment. No further recommendations for rewarming therapy were initiated.
Podiatry was consulted the following morning after admission. On examination, all toes were a gray/cyanotic color. Some erythema extended from the toes to the metatarsal areas of both feet. Multiple ruptured hemorrhagic bullae were present on all toes of both feet. A few hemorrhagic bullae were present on the dorsal and plantar aspects of the left foot. Some clear malodorous drainage was visible between the toes (see first two photos above). The neurological evaluation was abnormal with decreased light touch of the rearfoot up to the midfoot and a complete loss of sensation from the midfoot to toes bilaterally.
Initial treatment consisted of sharp debridement of ruptured bullae followed by irrigation with a diluted betadine solution. We placed dry gauze between the toes to allow for air circulation and wrapped the feet with Kerlix. We recommended discontinuation of Bacitracin and Xeroform dressings. Nurses had instructions to change the dressings every other day using diluted Betadine solution and to apply dry sterile dressings. Ace bandages were added along with elevation of lower legs for edema control. The patient started on cephalexin (Keflex) on admission, but this was switched to clindamycin after seven days, resolving malodorous drainage and erythema (see third photo above).
The injury gradually demarcated with dry gangrene of all toes and metatarsal heads at 3 weeks from presentation on the right foot and 4 weeks for the left foot. (See fourth photo above)
The patient underwent transmetatarsal amputation on the right foot 20 days after presentation. He returned to the operating room for a proximal transmetatarsal amputation of the left foot 27 days after presentation. Healing occurred uneventfully, and sutures were removed between two and three weeks after surgery.
The patient was discharged from the hospital without further complications 59 days after presentation. He had remained in the hospital through the entire course of treatment due to social factors of unstable housing and income, which a social worker addressed.
The patient presented at the podiatry outpatient clinic for follow-up care two weeks after discharge. On evaluation, the skin was completely healed, decreased protective sensations were present on both feet. We issued orthopedic boots and custom foot orthosis with toe fillers to patient. The patient was able to resume outdoor activities such as fishing 4 months after injury. He returned to the clinic 11 months after injury. (See fifth photo above) Skin remains closed, neurological deficit has not improved and most likely will be a lifelong sequela of the injury. The patient continues to use custom foot orthoses and orthopedic boots to perform his daily routine activities.
How To Prevent Frostbite
Prevention is the best therapy for frostbite. Experts advise that cold-induced numbness is the first sign before frostnip or frostbite sets in.1,4,5,7 It is important to preserve core temperature and hydration when expecting prolonged exposure to cold temperatures.The following steps are recommended to prevent cold injuries.1,3–5,7
1. Cover all skin including head, ears, and nose
2. Dress in layers rather than one heavy coat
3. Use proper foot gear and gloves; avoid tight fitting or restricting gear
4. Use appropriate nutrition and restraining from alcohol and drugs
5. Engage in moderate exercise, avoiding exhaustion and perspiration
6. Avoid prolonged exposure in extreme cold temperatures (below -15º C or 23º F)
7. Avoid nicotine products
A Review Of Treatment Recommendations And Modalities
The state of Alaska had developed the Cold Injuries Guidelines with algorithms and a helpful flow sheet to be used as a reference for treatment options for cold injuries including frostbite.4
Many facilities have also established proposed treatment pathways to facilitate the decision making and avoiding delays in treatment. The most widely accepted treatment modalities are listed below:
- Rapid rewarming. Immersion in warm water with temperature between 98.6º F to 102º F for about 30 minutes is preferable over passive rewarming if the area is still frozen and if the hospital care facility is more than two hours away. Avoid re-freezing the injured area. If the area is already thawed out, rapid rewarming is not beneficial.1,3–5,7,9
- Passive rewarming. Most frostbite will thaw spontaneously after removing the patient from the field. The use of reflective blankets, warm cotton blankets or forced-air systems is recommended.1,3
- Hydration. Use oral fluids if the patient is alert and capable. Use warm IV fluids infused in small rapid bolus.1,4,9
- Non-steroidal anti-inflammatory drugs (NSAIDs). These help reduce vasoconstriction and ischemia, and are also beneficial for pain management.1,4,5,7,9
- Tetanus prophylaxis. Frostbite increases the chances of tetanus.1,4,5,7,9
- Thrombolytic agents. TPA given during the first 24 hours may reduce the risk for amputation by helping restore blood flow to injured areas. (The IV form of iloprost is not approved to use in the USA, but studies are showing promising results reducing amputation rates if infused up to 72 hours after injury.)1,4–7,9
- Dressings. Clean injured areas; some experts recommend the use of warm water with antiseptic solution of povidone-iodine or chlorhexidine to reduce bacterial load. Place dry, sterile cotton gauze between fingers/toes. Some prefer to apply silver sulfadiazine or aloe vera ointments.1,2,4,5,7,8
- Edema control. Elevate injured areas and apply circumferential dressings over cotton dressing.1,4,7
- Blisters. Treatment for blisters remains controversial. Some recommend leaving blisters intact to prevent desiccation of the tissues underneath, but others prefer to aspirate fluids within blisters as they contain inflammatory mediators.1,2–4,7,8
- Activity. Rest and avoid weight bearing on the frostbitten extremity.1,4
- Oxygen. Supplemental oxygen is not recommended unless the patient is hypoxic since hyperoxia can cause vasoconstriction.1,4,9
- Hydrotherapy. This is recommended by some experts, but not enough studies regarding frequency of therapy has been established.1,4,7
- Imaging. Technetium 99 (Tc-99) triple phase scanning and magnetic resonance imaging (MRA) are recommended as MRA may help to assess blood supply and soft tissue integrity.1,3–5,7
- Surgery. Surgery is indicated only after tissues have demarcated usually between 3 and 12 weeks post-injury.1,4,5,7
- Prosthesis. It is preferable for the prosthesis to be custom fitted after the healing process is finalized with the intention to return to normal functioning as possible.
In Conclusion
Frostbite can usually be prevented with careful planning by being aware of surroundings, having adequate nutrition and using proper gear. If, however, injury does occur, reducing cold exposure time and rapid initiation of treatment can reduce extent of injury, lowering the risk of amputation.
Dr. Serrano practices at Alaska VA Health Care System in Anchorage, Alaska.
Dr. Dahlenburg practices at Alaska VA Health Care System in Anchorage, Alaska.
The authors would like to acknowledge the VA librarians' network for procuring articles relevant to this report.
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10. O'Malley J, Mills WJ, Kappes B, Sullivan S. Frostbite: general and specific treatment: the Alaskan Method. Alaska Med. 1993; 35(1):89–116.
