游离脂肪酸与全膝关节置换后隐性失血的相关性

Correlation of free fatty acids and hidden blood loss after total knee arthroplasty

背景:人工全膝关节置换后隐性失血是临床关注的焦点,关于隐性失血的病因有很多假说,然而没有一种能够合理的解释其作用机制。目的:分析游离脂肪酸与全膝关节置换后隐性失血的关系,探讨全膝关节置换后隐性失血的病因机制。方法:收集42例骨关节炎行初次单侧全膝关节置换患者的临床资料,记录置换术中及置换后显性失血量,分别收集患者置换前以及置换后24,48,72,96 h的血液样本,检测血液中血红蛋白、红细胞计数、红细胞压积和游离脂肪酸的变化趋势,应用Gross方程得出隐性失血量;同时对血液样本行涂片染色,在显微镜下观察红细胞形态变化。结果与结论:1血红蛋白和红细胞计数在置换后24,48 h明显下降,与置换前相比差异有显著性意义(P<0.01);2游离脂肪酸含量在置换后24 h内明显升高,在72,96 h后逐步降低恢复至置换前水平,同时在置换后24,48 h发生了显著的隐性失血,与游离脂肪酸含量呈正相关;3显微镜下可以观察到大量异型性红细胞在置换后24,48 h主要表现为细胞皱缩及破坏,在置换后96 h红细胞形态无明显异常;4结果提示,游离脂肪酸水平与全膝关节置换后隐性失血密切相关,置换术中应积极控制通过髓腔高压进入血液循环的脂肪颗粒,从而减少围置换期总失血量。

BACKGROUND：Hidden blood loss,after total knee arthroplasty,attracts surgeons＇ attention.There are various hypotheses about etiopathogenisis of hidden blood loss,but no one can reasonably explain its mechanism.OBJECTIVE：To research the correlation of free fatty acids and hidden blood loss after total knee arthroplasty,and explore the etiology and mechanism of hidden blood loss after total knee arthroplasty.METHODS：Clinical data of 42 osteoarthritis patients who underwent primary unilateral total knee arthroplasty were collected in this study.Intraoperative and postoperative dominant blood loss was recorded.Blood samples were collected preoperatively and 24,48,72,and 96 hours postoperatively.Changes in hemoglobin,erythrocyte count,hematocrit and free fatty acids were detected in blood.Hidden blood loss was obtained by Gross equation.Simultaneously,stains were added to the blood smear.Changes of cells morphology were observed under a microscope.RESULTS AND CONCLUSION：（1） Hemoglobin and erythrocyte count decreased significantly at 24 and 48 hours postoperatively,and significant differences were determined as compared with that preoperatively（P〈 0.01）.（2） Free fatty acids levels increased significantly within 24 hours after surgery,and decreased to preoperative levels at 72 and 96 hours later.Hidden blood loss was also significant at 24 and 48 hours after surgery,which showed positive correlation with free fatty acids content.（3） A plenty of abnormal erythrocytes were observed under the microscope.At 24 and 48 hours postoperatively,erythrocyte shrinkage and damage were mainly presented.At 96 hours,no significant abnormality was found.（4） These results indicated that free fatty acids were strongly associated with postoperative hidden blood loss.Surgeon should pay attention to the fatty droplets which may enter into the circulation in the process of reaming the femoral canal so as to reduce intraoperative total blood loss.