Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite: 2019 Update.

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each modality according to methodology stipulated by the American College of Chest Physicians. This is an updated version of the guidelines published in 2014.

Protective Effect of Extract of Ginkgo biloba 761 against Frostbite Injury in Rats.

BACKGROUND: When frostbite thaws, reperfusion injury has a crucial impact on tissue injury, and production of free radicals induces further tissue damage. This study examined whether extract of Ginkgo biloba 761 could ameliorate frostbite injury as a free radical scavenger. METHODS: Seventy-five Fisher 344 rats were divided into five groups of 15, and frostbite injury was created in each animal by sandwiching the left hind foot between a frozen magnet (-78.5°C) and a room-temperature magnet. Group I received saline; groups II, III, and IV received extract of Ginkgo biloba 761 (200, 100, and 50 mg/kg, respectively); and group V received superoxide dismutase (12 mg/kg). All drugs were injected intraperitoneally three times at 24-hour intervals. The wound surface area was measured throughout the wound healing period. Wounds were also harvested at various times to count cells stained by monoclonal antibodies for 4-hydroxy-2-nonenal and 8-hydroxy-2'-deoxyguanosine. RESULTS: Compared to group I, the wound surface area was significantly smaller in groups II and III on days 1 and 3 after wound creation. Histologic examination revealed significantly more 4-hydroxy-2-nonenal-stained cells and 8-hydroxy-2'-deoxyguanosine-stained cells in group I compared to other groups on day 1. However, there was no difference in the total healing period among the groups. A higher dose test of extract of Ginkgo biloba 761 (300 mg/kg daily) induced animal death, probably because of toxicity. CONCLUSION: Extract of Ginkgo biloba 761 demonstrated a protective effect against frostbite in the present model and probably alleviated reperfusion injury by reducing tissue peroxidation.

Wilderness Medical Society practice guidelines for the prevention and treatment of frostbite: 2014 update.

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for the prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks or burdens for each modality according to methodology stipulated by the American College of Chest Physicians. This is an updated version of the original guidelines published in Wilderness & Environmental Medicine 2011;22(2):156-166.

Wilderness Medical Society practice guidelines for the prevention and treatment of frostbite.

The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for the prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens for each modality according to methodology stipulated by the American College of Chest Physicians.

Emollients in the prevention of frostbite.

47% of Finnish conscripts had had at least one frostbite of the head (42% on the ears, 23% on the face) at the age of 19. Non-medicated ointments are traditionally used in Finland for protection against facial frostbite without scientific evidence of their benefit. In studies on cold protecting emollients it was found that 21% of the male conscripts in Finland had used them in the cold. 84% of the users had experienced their effect as somewhat or clearly protective. However, in a controlled prospective epidemiological study of 913 cold injuries of the head, the use of cold protective ointments was associated with an increased risk of frostbite to the head (odds ratio 4.5 for ear frostbite, 5.6 for nasal frostbite and 3.3 for frostbite on other parts of the face). The thermal insulation provided by different emollients in the cold was minimal in in vitro experiments using a skin model. In in vivo studies with test subjects the skin on the applied half of the face cooled at least as quickly as the untreated half. However, when white petrolatum was applied, the subjective skin perception of a test persons was warming in the majority of the tests, in contrast to objective measurements. "Protecting" emollients seem to cause a false sensation of safety leading to an increased risk of frostbite probably mainly through neglect of efficient protective measures.

A double-blind study of ultraviolet phototherapy in the prophylaxis of chilblains.

A randomized, double-blind study was carried out to assess the prophylactic value of ultraviolet irradiation in the autumn as a means of preventing the development of chilblains on the toes and fingers during the course of the winter. Placebo irradiation was achieved by means of an optical filter which absorbed all ultraviolet radiation from the lamps but allowed the visible light component to be transmitted, thus giving patients the impression that both limbs were being treated. Patients were reviewed at monthly intervals during the winter. The response between patients was variable; some patients developed chilblains whilst others remained symptom free. However, in no patient did the ultraviolet treated limb differ from the untreated limb. We conclude that the ultraviolet phototherapy is of no value in the prophylaxis of chilblains.