全膝关节置换术围手术期隐性失血的危险因素研究

目的探讨影响人工全膝关节置换术（TKA）术后隐性失血的危险因素及发生机制。方法选取2008年5月至2011年5月136位患者192例TKA，患者平均年龄67．5岁，其中单侧膝关节置换80例，双膝关节同期置换56例，同组医师采用同种术式完成，术后24h补液总量不超过2000ml。利用Gross方程，计算患者的术后总失血量，隐性失血量以及血红蛋白降低情况，记录年龄、性别、术侧、BMI、输血等危险因素，通过SPSS13．0进行统计学分析，比较各组之间隐性失血量有无差别，分析影响TKA围手术期隐性失血的危险因素。结果单侧TKA总失血量1650ml，隐性失血830ml；双膝同期置换者总失血量2864ml，隐性失血1487ml。无论是单侧还是双侧TKA，男性及应用自体血回输患者的围手术期失血量多于对照组（P〈0．01），双膝同期置换隐性失血量比例较大（X^2=6．836，P〈0．01），高龄肥胖患者隐性失血量明显多于对照组（单膝）X^2=21．587，P〈0．01，双膝X^2=29．233，P〈0．01）。结论TKA术后失血量较高，其中隐性失血比例占50％以上。男性双膝同期置换的患者，年龄〉70且BMI〉27．0，使用自体血回输均是增加围手术期隐性失血的危险因素。

Analysis of risk factors for perioperative hidden blood loss in total knee arthroplasty

Objective To study the risk factors related to pefioperative hidden blood loss in total knee arthroplasty （TKA） and clarify its mechanisms. Methods From May 2008 to May 2011, 136 patients with 192 knees involved were treated by TKA, including 80 unilateral TKAs and 56 bilateral TKAs. The average age of the patients was 67.5 years. All TKAs were managed by the same surgery group. The postoperative 24b fluid resuscitation was less than 2000 ml. Using Gross formula, the perioperative hidden blood loss and Hb drop were calculated. The factors such as age, sex, BMI and transfusion volume were recorded and analysed by SPSS 13.0 software. The risk factors affecting perioperative hidden blood loss were determined by calculating statistical difference between each group. Results The average volume of total perioperative blood loss in bilateral TKA was 1650 ml, while the volume of hidden blood loss was 830 ml; the average volume of total perioperative blood loss of unilateral TKA was 2864 ml, while the volume of hidden blood loss was 1487 ml. Both in unilateral or bilateral TKA groups, the volume of perioperative blood loss of male patients and the patients using autologous-transfusion device was more than that of the control group （ P 〈 0. 01 ）. The percentage of hidden blood loss of bilateral TKA was larger （ X^2 = 6. 836, P 〈 0. 01 ）. The blood loss of obese and old patients was significangtly more than that of the control group （ X^2 = 21. 587, P 〈 0. 01 in unilateral TKA group ; X^2 = 29. 233, P 〈 0. 01 in bilateral TKA group）. Conclusions There was a large volume of perioperative blood loss in TKA, among which the percentage of hidden blood loss was more than 50%. Male, elderly patients, bilateral operations and autologous transfusion maybe the risk factors that may increase the volume of perioperative hidden blood loss.