Objective: To investigate the changes of platelet mitochondrial mass and quantity during perioperative period in elderly patients, and assess their predictive values on the occurrence of postoperative delirium (POD). Methods: In this prospective study, 162 elderly patients scheduled for abdominal surgery under general anesthesia were enrolled from November 2021 to January 2022 in Nanjing Drum Tower Hospital Affiliated to Nanjing University Medical School. Among them, 20 patients [10 males, 10 females, aged (71.4±6.8) years] developed POD within 3 days after surgery (POD group), and another 20 patients[12 males, 8 females, aged (67.7±5.3) years] who did not develope POD were selected as controls (control group) using propensity score matching method. Blood samples were collected preoperatively, at the end of surgery and on the first postoperative day. Platelets were extracted and mitochondrial mass was detected with flow cytometry. Transmission electron microscopy was used to determine mitochondrial quantity. The receiver operating characteristic (ROC) curve was drawn to analyze the value of mitochondrial mass and quantity in predicting the occurrence of POD. Results: The mean fluorescence intensities of platelet mitochondrial mass were 193±46, 236±61, 264±53 preoperatively, at the end of surgery and on the first postoperative day in the POD group, respectively. The corresponding values were 209±61, 191±67 and 201±56 in the control group. The platelet mitochondrial mass of patients in the POD group was significantly increased on the first postoperative day compared to preoperative levels (P<0.001). In contrast, there was no significant difference in the control group (P=0.410). Patients in the POD group had higher platelet mitochondrial mass than patients in the control group on the first postoperative day(P=0.002). Meanwhile, platelets from patients in the POD group showed significantly higher number of mitochondria than platelets from patients in the control group [3 (2, 4) vs 2 (1, 2), P<0.001]. According to the ROC curve of platelet on the first postoperative day, at a mitochondrial mass cut-off value of>275.35, the sensitivity, specificity and area under the ROC curve to detect the occurrence of POD were 55%, 90% and 0.800 (95%CI: 0.666-0.934, P<0.001). At a mitochondrial quantity cut-off value of>2, the sensitivity, specificity and area under the ROC curve to detect the occurrence of POD were 53%, 78% and 0.680 (95%CI: 0.584-0.776, P<0.001). Conclusions: Patients who developed POD show higher platelet mitochondrial mass after surgery compared to preoperative levels. The mitochondrial mass of platelets on the first postoperative day has good predictive value on the occurrence of POD.
目的： 观察老年患者围手术期血小板线粒体质量及数量变化特征，并分析其对术后谵妄的预测价值。 方法： 前瞻性纳入2021年11月至2022年1月南京大学医学院附属鼓楼医院全身麻醉择期普外科腹部手术老年患者162例，根据患者术后3 d是否出现谵妄进行分组。其中谵妄组患者20例［男10例，女10例，年龄（71.4±6.8）岁］，采用倾向性评分匹配法从非谵妄患者中选择20例为对照组［男12例，女8例，年龄（67.7±5.3）岁］。收集两组患者术前、手术结束时、术后1 d外周血并提取血小板，使用流式细胞术检测线粒体质量，使用电镜分析线粒体数量。绘制受试者工作特征（ROC）曲线，分析血小板质量和数量对术后谵妄的预测价值。 结果： 谵妄组患者术前、手术结束时、术后1 d血小板线粒体质量荧光强度分别为193±46、236±61、264±53，对照组分别为209±61、191±67、201±56；谵妄组患者术后1 d线粒体质量与术前相比显著升高（P<0.001），对照组患者术后1 d线粒体质量与术前相比差异无统计学意义（P=0.410）；与对照组相比，谵妄组患者术后1 d线粒体质量增加（P=0.002）。术后1 d谵妄组患者血小板线粒体数量为3（2，4）个，显著高于对照组的2（1，2）个（P<0.001）。术后1 d血小板线粒体质量荧光强度cut-off值为>275.35时，其预测术后谵妄发生的灵敏度为55%，特异度为90%，ROC曲线下面积为0.800（95%CI：0.666~0.934，P<0.001）。血小板线粒体数量cut-off值>2个时，其灵敏度为53%，特异度为78%，ROC曲线下面积为0.680（95%CI：0.584~0.776，P<0.001）。 结论： 谵妄组患者术后1 d血小板线粒体质量较术前增加，对术后谵妄的发生具有良好的预测价值。.