Kung C C, Lin S Y, Tang C S, Wu T J, Sun W Z
Department of Anesthesiology, Taipei Municipal Chung-Hsiao Hospital, Taiwan, Republic of China.
Kaohsiung J Med Sci. 1998 Aug;14(8):486-91.
Continuous spinal anesthesia (CSA) has been considered to be better in temporal and dose flexibility, as well as hemodynamic stability than single dose spinal anesthesia. However, the failure of spinal anesthesia is not a rare experience for anesthesiologists. Here we present our experience in solving the problem and discuss the possible causes for the failure.
236 cases were studied retrospectively from January to December in 1996. All were over 65 years old, ASA III, scheduled for transurethral procedures or orthopedic operation. CSA was performed with 0.2% bupivacaine. Failed CSA was confirmed by positive pin-prick test at T10 dermatome(umbilicus) 30 minutes after 20 mg bupivacaine was injected. For failed cases, 5 mL 1% lidocaine was injected intrathecally for rescue. The failure rate, sensory and motor blockade, success rate by changing to lidocaine and its dosage were recorded.
Eleven of 236 cases (4.7%) were considered spinal failure since the initial 20 mg bupivacaine could not provide adequate T10 anesthesia in 30 minutes. Addition of 5 mL 1% lidocaine produced a profound sensory and motor blockade in 9 cases, while further lidocaine injection was required in two cases. The success rate by rescuing lidocaine was 100% with an average lidocaine consumption by 52.5 +/- 4.5 mg.
Factors contributed to failure spinal anesthesia including failure of technique, errors of judgment, maldistribution and failure of local anesthetic itself. However, we thought that change of pH value of local anesthetic in CSF may play a great part in these failed CSAs. Despite the reasons for failure, we demonstrate that failure of continuous spinal anesthesia by 0.2% bupivacaine can be readily resolved by 1% lidocaine.
连续脊麻（CSA）在时间和剂量灵活性以及血流动力学稳定性方面被认为优于单次脊麻。然而，脊麻失败对于麻醉医生来说并非罕见。在此我们介绍我们解决该问题的经验并讨论失败的可能原因。
回顾性研究1996年1月至12月间的236例患者。所有患者年龄均超过65岁，ASA分级为III级，计划行经尿道手术或骨科手术。采用0.2%布比卡因进行CSA。在注入20mg布比卡因30分钟后，通过T10皮节（脐部）针刺试验阳性确认CSA失败。对于失败病例，鞘内注射5ml 1%利多卡因进行补救。记录失败率、感觉和运动阻滞情况、改用利多卡因后的成功率及其剂量。
236例中有11例（4.7%）被认为脊麻失败，因为最初的20mg布比卡因在30分钟内未能提供足够的T10麻醉。追加5ml 1%利多卡因后，9例产生了深度感觉和运动阻滞，2例需要进一步注射利多卡因。利多卡因补救的成功率为100%，平均利多卡因用量为52.5±4.5mg。
导致脊麻失败的因素包括技术失败、判断错误、分布不均和局部麻醉药本身失效。然而，我们认为脑脊液中局部麻醉药pH值的变化可能在这些失败的CSA中起很大作用。尽管有失败的原因，但我们证明0.2%布比卡因所致连续脊麻失败可通过1%利多卡因轻松解决。
