全膝关节置换术后隐性失血危险因素的分析

目的探讨全膝关节置换术后的隐性失血量,并分析影响隐性失血的相关因素。方法收集48例行初次单侧全膝关节置换术的患者,其中女42例,男6例;年龄29～79岁,平均年龄65岁。通过Gross方程,根据患者身高、体重和手术前后的红细胞压积(Hct)计算患者的总失血量,减去显性失血量后得隐性失血量。分析年龄、性别、诊断、身高、体重、BMI、术中出血量、术后引流量、术者以及止血带时间、手术时间与隐性失血的相关性。结果术中出血量为(541±271)mL(200～1700mL),术后引流量为(479±249)mL(50～1010mL),显性出血量为(1020±327)mL(440～2 220 mL),总失血量为(1 963±734)mL(92～3 926 mL),隐性失血量为(942±692)mL(-502～2 716 mL)。因此,隐性失血占总失血的48.0%。隐性失血与身高、体重都有明显正相关,但与BMI没有明显相关性,另外,隐性失血还与术后引流量呈明显负相关。结论全膝关节置换术后隐性失血量约占总失血量的一半,应引起我们足够的重视,并且术后引流量少时更不能忽视隐性失血的存在。

Analysis of Risk Factors of Hidden Blood Loss in Total Knee Arthroplasty

Objective To explore the hidden blood loss in total knee arthroplasty(TKA) and determine the factors affecting the hidden blood loss.Methods 48 consecutive patients(42 females,6 males)underwent primary unilateral TKA were included in the present study.The average age was 65 years old.The total blood loss was calculated through Gross formula by using height,weight,pre-and post-operative hematocrit.Hidden blood loss was calculated by subtracting the visible total blood loss from the total blood loss.Correlation analysis was performed between hidden blood loss and age,sex,diagnosis,height,weight,BMI,intra-operative blood loss,post-operative blood loss,operator,the tourniquet time and the operation time.Results The intra-operative blood loss was 541±271 mL(200～1 700 mL),post-operative blood loss was 479±249 mL(50～1 010 mL),visible blood loss was 1020±327 mL(440～2 220 mL).Total blood loss was 1 963±734 mL(92～3 926 mL),hidden blood loss was 942±692 mL(-502～2 716 mL).The hidden blood loss accounts for 48% of total blood loss.Hidden blood loss was positively correlated with height,weight,but not significantly correlated with BMI;hidden blood loss was also negatively correlated with post-operative blood loss.Conclusion Orthopaedic surgeons should not neglect the hidden blood loss as it accounts for about half of total blood loss in TKA,especially when the post-operative blood loss was small.