Treatment of 568 patients with frostbite in northeastern China with an analysis of rate of amputation

Objective To study the key points of treatment and amputation in patients with frostbite, so as to increase the successful rate of the treatment. Methods Five hundred and sixty-eight patients with frostbite admitted to our department from January 2005 to December 2014. (1) For the patients admitted to our department within one week after injury, the frostbite wounds were soaked in 42 ℃ herbal fluid (twice per day, 30 min for each time) and irradiated with infrared or red light (three times per day, 40 min for each time) from the day of admission to the 7th day after injury. Meanwhile, treatment for improvement of microcirculation, vasodilation, and anti-infection were also given. Then they received infrared or red light irradiation to the wound sites. For the patients admitted to our department longer than one week after frostbite, the frostbite wounds were irradiated with infrared or red light, and treated with antibiotics if inflammation was found around the wound. Among all the patients, 5 cases suffered from frozen stiff, and they were given fluid resuscitation as well as above-mentioned treatments after admission. (2) All patients were given wound treatment immediately after admission. The superficial partial-thickness wounds and deep partial-thickness wounds of 264 patients were given routine dressing change. The full-thickness wounds in 79 patients were treated with exposure therapy after routine dressing change first, and then granulation tissue of these wounds were grafted with autologous thigh split-thickness skin grafts. After debridement and exposure therapy, amputation was done in 225 patients 3 to 4 weeks after injury when the underlying bone was exposed. In 4 patients with exposure of calcaneus, the wounds were covered with reverse sural nerve nutrient vessels island flap. Mean healing time of superficial partial-thickness wound and deep partial-thickness wound, survival rate of skin graft in full-thickness wound, and survival rate of flap covering wound deep to bone at the heel were all recorded. The amputation rate of patients injured in December, January, February, and other months, that of patients admitted shorter than 1 day after frostbite, 1 to 3 days after frostbite, longer than 3 days and shorter than or equal to 5 days after frostbite, and longer than 5 days after frostbite, that of patients caused by drunkenness, mental disorders, improper protection, going astray, and trauma including traffic accident etc., and that of patients treated with rewarming under room temperature, rubbing with snow, wrapping with quilt, and soaking in warm water before admission were all recorded and analyzed. Parts of the data were processed with χ² test. Results All patients were survived after treatment. Average wound healing time of superficial partial -thickness wound and deep partial-thickness wound was respectively 10 and 23 days. The survival rate of skin graft on full-thickness wound was about 95%. Survival rate of flap on wound deep to bone at the heel was 100%. Amputation rates of patients injured in December and January were respectively 47.46% (84/177), 42.56% (103/242), and both were significantly higher than those of patients injured in February and the other months [respectively 29.55% (26/88), 13.11% (8/61), with χ² values from 42.595 to 220.900, P values below 0.01]. Amputation rate of patients with admission time shorter than 1 day after frostbite was 32.06% (84/262), which was obviously lower than that of patients with admission time from 1 to 3 days after frostbite, longer than 3 days and less than or equal to 5 days after frostbite, or longer than 5 days after frostbite [respectively 40.48% (68/168), 49.02% (50/102), 52.78% (19/36), with χ² values from 107.284 to 165.350, P values below 0.01]. Amputation rates of patients with frostbite occurring after getting drunkenness, mental disorders, and trauma including traffic accident etc. were respectively 42.06% (106/252), 43.48% (60/138), and 53.12% (17/32), and they were all significantly higher than those of patients with frostbite caused by improper protection and going astray [respectively 27.45% (28/102), 22.73% (10/44), with χ² values from 187.260 to 209.738, P values below 0.01]. Amputation rates of patients undergoing treatment of rewarming under room temperature, rubbing with snow, wrapping with quilt before admission were respectively 44.29% (62/140), 48.28% (84/174), and 35.38% (46/130), and they were significantly higher than the amputation rate of patients who received the treatment of soaking in warm water [23.39% (29/124), with χ² values from 97.364 to 136.189, P values below 0.01]. Conclusions Early diagnosis and treatment, properly rewarming at early stage, and correct wound treatment are the key points for reducing amputation rate of patients after frostbite. Attention should be paid to the occurrence of frostbite in December and January, and also to protection of high-risk groups (patients with mental disorders and drunker).