背景:脊柱麻醉是老年患者(>60岁)接受下肢手术的常规麻醉技术,下腹部,骨盆和会阴.脊柱麻醉比全身麻醉有几个优点,包括稳定的血流动力学变量,减少失血,术后疼痛减轻,更快的恢复时间和更少的术后混乱。尽管有这些优势,脊髓麻醉引起的交感神经阻滞可导致低血压,心动过缓,心律失常和心脏骤停.传统上,脊髓麻醉在L3,4间隙水平进行;据报道,老年人低血压的发生率在65%至69%之间.减少脊髓诱导的低血压的可能策略是将峰值块高度最小化至尽可能低的计划程序。
目的:确定在L5,S1间隙接受脊髓麻醉的老年患者与在L3,4间隙接受脊髓麻醉的老年患者的血流动力学稳定性的差异。
方法:使用计算机生成的数字表,将32例老年患者在脊柱麻醉下进行下肢或骨盆手术随机分为2组(对照组和干预组)。对照组;在L3,4间隙和干预组鞘内注射2.5ml0.5%高压布比卡因;在L5,S1间隙鞘内注射2.5ml0.5%高压布比卡因。
结果:两组在年龄方面具有相似的基线特征,性别,体重指数和抗高血压药物的使用。对照组出现低血压的比例为68.8%,干预组出现低血压的比例为75%。没有发现差异有统计学意义(p=0.694)。在学习期间,有106次低血压发作,其中,对照组65例,干预组41例(p=0.004)。.平均动脉压(MAP)下降的线性回归分析显示,对照组的MAP下降幅度更大(p0.018)。对照组(1006mls±374)比干预组(606mls±211)使用的晶体更多,p<0.0001。两组之间使用的血管加压药的量没有差异(p=0.288)。心率的变化没有差异,转换为全身麻醉,使用补充静脉芬太尼和达到的峰值最大阻滞水平。对照组和干预组达到最大感觉阻滞水平的时间分别为9.06min和13.07min,分别(p<0.0001)。
结论:在该人群中,在L3,4接受脊髓麻醉的老年患者与在L5,S1接受脊髓麻醉的老年患者之间低血压的比例没有差异.干预组有更好的结果,低血压发作明显减少。干预组达到最大峰值感觉阻滞需要更长的时间。在L5,S1水平进行脊髓麻醉被发现为广泛的骨盆提供了足够的感觉阻滞,会阴和下肢手术。
BACKGROUND: Spinal anaesthesia is a routinely used anaesthetic technique in elderly patients (> 60 years) undergoing operations involving the lower limbs, lower abdomen, pelvis and the perineum. Spinal anaesthesia has several advantages over general anaesthesia including stable haemodynamic variables, less blood loss, less post-operative pain, faster recovery time and less post-operative confusion. Despite these advantages, the sympathetic blockade induced by spinal anaesthesia can result in hypotension, bradycardia, dysrhythmias and cardiac arrests. Conventionally, spinal anaesthesia is performed at the level of L3,4 interspace; with a reported incidence of hypotension in the elderly ranging between 65% and 69%. A possible strategy for reducing spinal induced hypotension would be to minimize the peak block height to as low as possible for the planned procedure.
OBJECTIVE: To determine the difference in haemodynamic stability between elderly patients undergoing spinal anaesthesia at L5, S1 interspace compared to those at L3, 4.
METHODS: Thirty two elderly patients scheduled for lower limb or pelvic surgery under spinal anaesthesia were randomized into 2 groups (control group and intervention group) using a computer generated table of numbers. Control group; received 2.5 mls 0.5% hyperbaric bupivacaine injected intrathecally at the L3, 4 interspace and Intervention group; 2.5mls 0.5% hyperbaric bupivacaine injected intrathecally at the L5, S1 interspace.
RESULTS: The two groups had similar baseline characteristics in age, sex, body mass index and use of anti-hypertensive medications. There was 68.8% proportion of hypotension in the control group and 75% in the intervention group. The difference was not found to be statistically significant (p= 0.694). During the
study period, there were 106 episodes of hypotension, out of which, 65 were in the control group and 41 in the intervention group (p=0.004).. Linear regression analysis of the decrease in mean arterial pressures (MAP) showed a higher decrease in MAP in the control group (p 0.018). There were more crystalloids used in the control group (1006mls ± 374) than in the intervention group (606mls ±211) with a p< 0.0001. There was no difference in the amounts of vasopressors used between the two groups (p=0.288). There was no difference in the change in heart rates, conversion to general anaesthesia, use of supplementary intravenous fentanyl and the peak maximum block level achieved. The time to peak maximum sensory block level was 9.06min and 13.07min in the control group and intervention groups, respectively (p<0.0001).
CONCLUSIONS: Among this population, there was no difference in the proportion of those with hypotension between the elderly patients who received their spinal anaesthesia at L3,4 and those who received spinal anaesthesia at L5,S1. The intervention group had better outcomes with significantly less episodes of hypotension. It took a longer time to achieve a maximum peak sensory block in the intervention group. Performing spinal anaesthesia at the level of L5,S1 was found to provide an adequate sensory block for a wide range of pelvic, perineal and lower limb surgeries.