Methods and pathophysiology of rewarming in case of local cold injury. Literature review

Nowadays, rewarming of the affected tissues is the primary method of treatment for patients with cold injuries. But the warming manipulation has its own characteristics and limitations, depending on specific circumstances. Untimely and incorrectly performed rewarming can lead to a significant increase in the level of dangerous complications, mortality, and disability. The rewarming strategy is implemented according to one of the two scenarios. If there is a risk of freezing again, the injured area is not actively rewarmed; it is just immobilized, and thermo‑insulating bandages are applied. Slow warming with body heat is also acceptable. If the frozen area can be warmed and kept warm without refreezing until the evacuation is completed, a quick warming with warm water or special heating blankets is preferable. Recommendations on the ideal water temperature significantly differ among authors and include a wide range between 37 °C and 43 °C. The extent of damage to the tissues becomes obvious only after thawing. The traditional classification system of local cold injuries distinguishes four degrees of frostbite. First‑degree frostbite presents with superficial damage to the skin; second‑degree frostbite involves deep skin damage; third‑degree frostbite results in full‑thickness skin damage, including the subcutaneous and surrounding tissues; and fourth‑degree frostbite causes deep necrosis of the subcutaneous structures. Depending on the extent of damage, patients may experience constant and severe pain during rewarming, so analgesics should be prescribed to relieve it. It is recommended to use topical agents (creams, gels, and ointments) to improve circulation and prevent and treat infection. Tissue necrosis with severe frostbite requires surgical treatment of wounds. The authors hope that the provided information will be useful to doctors‑of‑first‑ contact and in hospital conditions in order to optimize the treatment of local cold injuries.