苯肾上腺素预输注防治老年人脊麻后低血压的临床研究

目的 评估预防性输注苯肾上腺素用于防治老年人脊麻后低血压的疗效和安全性。方法 将2017年1月~4月在本院行骨科下肢手术且年龄超过60岁的52例患者，随机分为P组和C组，每组26例。两组患者均使用0.5%布比卡因2 ml进行腰麻，P组在腰麻注药后立即静脉给予苯肾上腺素（100 μg/ml）1 ml/min，C组给予生理盐水1 ml/min。观察两组患者的术中MAP、每例患者低血压、高血压、心动过缓的发作次数，发作低血压、高血压、心动过缓的患者数，初次低血压的发作时刻，术中最低和最高MAP，苯肾上腺素和液体的总使用量，术后6 h、24 h、48 h发生心电图改变的患者数以及肌钙蛋白增加的患者数。结果 P组MAP高于C组，初次低血压的发作时刻大于C组，差异有统计学意义（P＜0.05）。P组每例患者低血压的发作次数少于C组，差异有统计学意义（P＜0.05）。两组患者发生低血压的患者数、术中最低和最低MAP比较，差异无统计学意义（P＞0.05）。P组患者的无低血压发作的累计比例高于C组，差异有统计学意义（P＜0.05）。两组患者术中发生高血压和心动过缓例数、每例患者高血压和心动过缓的发作次数、术中液体总使用量比较，差异无统计学意义（P＞0.05）。P组的苯肾上腺素总使用量高于C组（P＜0.05）。两组患者在术后6 h、24 h均未发生心电图异常改变情况。P组患者在术后48 h内未发生心电图异常改变情况，C组有2例患者（7.69%）在术后48 h发生了心电图异常改变，两组差异无统计学意义（P＞0.05）。C组患者在术后6 h、24 h、48 h发生肌钙蛋白定量升高的患者数均高于P组，但差异无统计学意义（P＞0.05）。结论 预防性输注苯肾上腺素可有效防治老年人脊麻后低血压，减少低血压发作次数，延迟低血压发作时间，提高手术麻醉的安全性。

Clinical Study of Phenylephrine Pre-infusion for Prevention and Treatment of Hypotension after Spinal Anesthesia in the Elderly

Objective To evaluate the efficacy and safety of prophylactic infusion of phenylephrine for the prevention and treatment of hypotension after spinal anesthesia in the elderly.Methods A total of 52 patients who underwent orthopaedic surgery in the hospital from January to April 2017 and were over 60 years old were randomly divided into group P and group C,with 26 cases in each group. Two groups of patients were treated with 0.5% bupivacaine 2 ml for spinal anesthesia.Group P received intravenous phenylephrine (100 μg/ml)1 ml/min immediately after spinal anesthesia,and group C received normal saline 1 ml/min.The intraoperative MAP of each group,the number of episodes of hypotension,hypertension,bradycardia,the number of patients with hypotension,hypertension,and bradycardia,the time of initial hypotension,the lowest and highest MAP,total phenylephrine and fluid use during surgery,the number of patients with ECG changes at 6 h,24 h,and 48 h after surgery,and the number of patients with increased troponin.Results The MAP of group P was higher than that of group C.The time of initial hypotension was greater than that of group C,the difference was statistically significant(P<0.05).The number of episodes of hypotension in each patient in group P was less than that in group C,the difference was statistically significant(P<0.05).There were no significant differences in the number of patients with hypotension, intraoperative minimum and minimum MAP between the two groups(P>0.05).The cumulative proportion of patients without hypotension in group P was higher than that in group C,the difference was statistically significant(P<0.05).There were no significant differences in the number of intraoperative hypertension and bradycardia,the number of episodes of hypertension and bradycardia in each group,and the total amount of intraoperative fluid used in the two groups(P>0.05).The total dose of phenylephrine in group P was higher than that in group C(P<0.05).ECG abnormalities did not occur in the two groups at 6 h and 24 h after surgery.There was no abnormal ECG change in group P within 48 hours after operation.Two patients in group C(7.69%)had abnormal ECG changes at 48 hours after operation.There was no significant difference between the two groups(P>0.05).The number of patients with elevated troponin levels at 6 h,24 h,and 48 h after operation in group C was higher than that in group P,but the difference was not statistically significant(P>0.05).Conclusion Prophylactic infusion of phenylephrine can effectively prevent hypotension after spinal anesthesia,reduce the number of hypotension episodes,delay the onset of hypotension,and improve the safety of surgical anesthesia.