探讨人体感觉阻滞平面上升速率，对剖宫产术腰硬联合麻醉(CSEA)后低血压的预测价值。

选择2019年1月至12月，于成都医学院第二附属医院·核工业四一六医院进行择期剖宫产术分娩，美国麻醉医师协会(ASA)分级为Ⅰ～Ⅱ级的单胎妊娠产妇80例为研究对象。根据产妇是否发生CSEA后低血压，将其分为低血压组(n＝36)与对照组(n＝44)。对2组产妇采取L3～4腰椎间隙CSEA，于蛛网膜下腔15 s内推注0.5%重比重布比卡因2.4 mL。2组产妇CSEA注射药物后15 min内，每1 min监测1次生命体征、感觉阻滞平面及其时间，并采用成组t检验或Wilcoxon秩和检验对其进行统计学比较。绘制受试者工作特征(ROC)曲线，分析人体感觉阻滞平面上升速率(人体感觉阻滞平面达T8、T6的时间)，对于预测剖宫产术分娩产妇发生CSEA后低血压的价值，并确定其最佳临界值。本研究方案经病例收集医院伦理委员会批准[审批文号：2018年审(030)号]，并与受试者签署临床研究知情同意书。2组产妇年龄、身高、孕龄、人体质量指数(BMI)、脑脊液流出时间、CSEA注射药物后至恢复仰卧位时间、CSEA注射药物前输液量，术中输液量、失血量及尿量等一般临床资料比较，差异均无统计学意义(P>0.05)。

①低血压组产妇发生CSEA后低血压时，人体感觉阻滞平面为T5(T6～T4)，发生CSEA后低血压的时间为CSEA注射药物后8 min(7～8 min)，均显著低于组内人体感觉最高阻滞平面T4(T4～T3)和短于组内人体感觉达最高阻滞平面的时间CSEA注射药物后10 min(9～11 min)，并且差异均有统计学意义(Z＝-5.030、P<0.001, Z＝-6.732、P<0.001)。低血压组产妇人体感觉阻滞平面达T8、T6与最高阻滞平面的时间分别为CSEA注射药物后3 min(3～4 min)、6 min(5～7 min)与10 min(9～11 min)，均显著短于对照组的CSEA注射药物后5 min(5～6 min)、8 min(7～9 min)与11 min(10～12 min)，而低血压组人体感觉最高阻滞平面T4(T4～T3)显著高于对照组的T5(T5～T4)，2组比较，差异均有统计学意义(Z＝-5.832、-4.202、-3.369、-3.399，均为P<0.001)。②对人体感觉阻滞平面达T8、T6的时间预测剖宫产术分娩产妇发生CSEA后低血压的ROC曲线分析结果显示，其曲线下面积(AUC)分别为0.871(95%CI：0.787～0.955，P<0.001)与0.769(95%CI：0.661～0.856，P<0.001)。根据约登指数最大原则，人体感觉阻滞平面达T8、T6的时间预测剖宫产术分娩产妇发生CSEA后低血压的最佳临界值分别为CSEA注射药物后4 min与7 min，此时其约登指数分别为0.664、0.407，敏感度分别为77.8%与54.6%，特异度分别为88.6%与86.1%，前者预测剖宫产术分娩产妇发生CSEA后低血压的价值更高。

人体感觉阻滞平面上升速率可预测剖宫产术分娩产妇CSEA后低血压的发生，可为剖宫产术CSEA后低血压的预警与及时干预提供参考。

To explore prediction value of rising rate of sensory level on combined spinal-epidural anesthesia (CSEA) induced hypotension during cesarean section.

A total of 80 singleton pregnant women with American Society of Anesthesiologists (ASA) grade Ⅰ-Ⅱ who underwent elective cesarean section in the Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital from January to December 2019, were selected as research subjects. All pregnant women were divided into hypotension group (n=36) and control group (n=44), according to whether development of CSEA induced hypotension or not. All of them underwent CSEA in L3-4 intervertebral space and were injected with 2.4 mL of 0.5% hyperbaric bupivacaine into subarachnoid space (injection time was 15 s). The vital signs, sensory level and time of pregnant women in two groups were detected once per minute within 15 minutes after CSEA, and above indicators were statistically compared by independent-samples t test or Wilcoxon rank-sum test. The receiver operating characteristic (ROC) curve was drawn to analyze predictive value of rising rate of sensory level (at the time of sensory level reaching T8 and T6) on CSEA induced hypotension in pregnant women with elective cesarean section, and to determine the optimal cut-off value. This research was approved by the Ethics Committee of the Second Affiliated Hospital of Chengdu Medical College & Nuclear Industry 416 Hospital [Approval No. 2018(030)], and informed consent forms for clinical research was signed with each research subject. There were no significant differences in age, height, gestational age, body mass index (BMI), cerebrospinal fluid outflow time, the time from CSEA to supine position, infusion volume before CSEA, intraoperative infusion volume, blood loss volume and urine volume between two groups (P>0.05).

①When CSEA induced hypotension occurred in hypotension group, sensory level was T5 (T6-T4), and the time of occurrence of CSEA induced hypotension was 8 min (7-8 min) after CSEA injection, which were significantly lower than upper sensory level as T4 (T4-T3) and shorter than the time of reaching upper sensory level at 10 min (9-11 min) after CSEA injection, and both differences were statistically significant (Z=-5.030, P<0.001; Z=-6.732, P<0.001). The time of sensory level reaching T8, T6 and upper sensory level in hypotension group was 3 min (3-4 min), 6 min (5-7 min) and 10 min (9-11 min) after CSEA injection, respectively, which was significantly shorter than those in control group at 5 min (5-6 min), 8 min (7-9 min) and 11 min (10-12 min) after CSEA injection, while upper sensory level T4 (T4-T3) was significantly higher than that in control group T5 (T5-T4), and all differences between two groups were statistically significant (Z=-5.832, -4.202, -3.369, -3.399; P all<0.001). ②ROC curve analysis results of the time of sensory level reaching T8, T6 for predicting CSEA induced hypotension of pregnant women with elective cesarean section showed that area under curve (AUC) of them were 0.871 (95%CI: 0.787-0.955, P<0.001) and 0.769 (95%CI: 0.661-0.856, P<0.001), respectively. According to the principle of maximum Youden index, the optimal cut-off values of time of sensory level reaching T8, T6 for predicting CSEA induced hypotension of pregnant women with elective cesarean section were 4 min and 7 min after CSEA injection, respectively. And Youden indexes were 0.664 and 0.407, sensitivities were 77.8% and 54.6%, and specificities were 88.6% and 86.1%, respectively. The former was more valuable in predicting occurrence of CSEA induced hypotension in pregnant woman with elective cesarean section.

Rising rate of sensory level can be used to predict the occurrence of CSEA induced hypotension in pregnant women during cesarean section, and provide a reference for early warning and timely intervention of CSEA induced hypotension in perioperative period of cesarean section.