(1) Non-frostbite: Frostbite generally occurs in winter and early spring in China, and it is more common in the Yangtze River valley than in the north. Because although the temperature in the Yangtze River basin is higher than that in the north in winter, it is humid and the cold-proof measures are not as good as those in the north. Children often ignore the cold, so frostbite is common. Trench foot and immersion foot often occur in wartime. The former is caused by standing in the trench of 1℃ ~ 10℃ for a long time, while the latter is caused by standing in cold water. In normal times, these two kinds of frostbite can also occur in some buildings, paddy fields or military tasks. The onset is often unconscious, and it can only be detected when the hands, feet, ear shells and other parts appear red and swollen, local redness or purple, swelling, itching or tingling; Some will cause blisters, and then erosion or scab.
Keep warm to prevent frostbite. In winter, people working in the field and on duty should have cold-proof and waterproof clothes. People who have suffered from chilblain should soak in eggplant straw decoction or rub sensitive parts with ginger or apply chilblain cream before the frequent season. After chilblain occurs, chilblain cream can be applied locally, and the erosive part can be bandaged with ointment containing antibiotics and cortisone.
(2) Frostbite: local frostbite and systemic frostbite (frostbite) mostly occur in accidents or wartime, and the human body is exposed to low temperature below freezing point, such as being caught in a snowstorm in the wild, being trapped by ice and snow, or being accidentally injured by refrigerants (liquid nitrogen, solid carbon dioxide, etc.). ) at work. Local frostbite makes the skin pale, cold, painful and numb. The local manifestations after rewarming are similar to burns, which are generally divided into four degrees.
First-degree frostbite: epidermal damage. Local redness, fever, itching and tingling. After a few days, the epidermis is dry and healed, leaving no scars.
Second degree frostbite: the damage reaches the dermis. The local swelling is obvious, forming blisters, which are serum-like liquid or slightly bloody, and the pain is dull. After 2 ~ 3 weeks of scab healing, some scars still exist.
Third degree frostbite: damage to the whole skin or subcutaneous tissue. The wound changed from pale to dark brown, the pain disappeared, skin grafting was needed, and the healing was slow, leaving scars.
Fourth degree frostbite: the damage extends to muscles, bones and other tissues. There are many kinds of dysfunction or disability after cure.
In the early stage of frostbite, there are chills, pallor, cyanosis, fatigue, weakness, yawning and other manifestations, followed by limb stiffness, hallucinations or confusion or even coma, arrhythmia, respiratory depression, and finally cardiac arrest. If it can be rescued, the patient's heartbeat and breathing can be restored, but ventricular fibrillation, hypotension and shock often occur. Pulmonary edema, acute renal failure and other organ dysfunction may also occur.
When frostbite occurs, the patient should be separated from the low temperature environment and frozen objects quickly, and the temperature should be rewarming immediately. Soak the injured limb or whole body with warm water of 38℃ ~ 42℃, with sufficient water and the water temperature is stable for about 20 minutes. Be careful not to smear scratches with ice and snow after frostbite, and don't bake with a stove. After rewarming, the first frostbite wound is kept clean and dry, and it can be healed in a few days. After the second degree of frostbite disinfection, the dry wound can be wrapped with soft dry gauze; If there is a blister, the liquid in the blister can be sucked out and wrapped with soft dry gauze, or exposed after being coated with chilblain cream. Exposure therapy is often used for third-degree and fourth-degree frostbite to keep the wound clean and dry, and necrotic tissue should be removed when the boundary is clear. If there is infection, it should be fully drained; Patients with wet gangrene usually need amputation. Small area of first or second degree frostbite can be treated at home, while large area of second degree frostbite and third or fourth degree frostbite are serious and have many complications, which often require systemic treatment and surgical treatment, and hospitalization is appropriate.