Frank A, Schuster M, Biscoping J
Klinik für Anästhesie und Operative Intensivmedizin, St. Vincentius-Kliniken gAG Karlsruhe, Germany.
Anasthesiol Intensivmed Notfallmed Schmerzther. 2002 Nov;37(11):659-64. doi: 10.1055/s-2002-35119.
Unilateral spinal anaesthesia ("hemi-spinal") is theoretically associated with the advantages of fewer cardiovascular effects and longer duration of action while offering high density motor block of the extremity affected.
In a prospective, randomised study 60 patients received 2 mls of 4 % hyperbaric mepivacaine intrathecally. Group I (n = 30) was returned into the supine position after 5 minutes in the lateral position, Group II (n = 30) was kept in the lateral position for 15 minutes. Spread and subsequently offset of sensory and motor block were assessed separately for each side at predetermined time intervals pre-, intra-, and postoperatively.
Both groups were identical regarding their morphometric parameters. In Group I (5 minutes), the mean cephalad spread of sensory block of the initially dependent side was T6 after 15 mins and T4 after 25 mins. On the initially non-dependent side, the sensory block reached to T5 after 25 mins. In Group II (15 mins), the initial mean difference was equivalent to two segments (T7/T9). After 25 minutes there was no difference to the results in Group I.
Unilateral spinal anaesthesia ("hemi-spinal") is an attractive concept, supposed to be associated with the above mentioned advantages and the additional benefit of a partially maintained sensation of one limb. The results demonstrated in this study seriously question this theoretical concept. The most likely reason for the lack of inter-lateral differences in sensory block is the high concentration of hyperbaric local anaesthetic in the cerebrospinal fluid on the dependent side, which, on turning the patient to the supine position, will transit to the previously non-dependent side subsequently leading to a significant block.
单侧脊髓麻醉（“半脊髓”）理论上具有心血管影响较小、作用时间较长的优点，同时能对受影响肢体提供高密度运动阻滞。
在一项前瞻性随机研究中，60例患者鞘内注射2毫升4%的高压甲哌卡因。第一组（n = 30）在侧卧位5分钟后恢复仰卧位，第二组（n = 30）保持侧卧位15分钟。在术前、术中和术后的预定时间间隔分别评估每侧感觉和运动阻滞的扩散及随后的消退情况。
两组在形态学参数方面相同。在第一组（5分钟）中，最初依赖侧感觉阻滞的平均头侧扩散在15分钟后为T6，25分钟后为T4。在最初非依赖侧，25分钟后感觉阻滞达到T5。在第二组（15分钟）中，初始平均差异相当于两个节段（T7/T9）。25分钟后与第一组结果无差异。
单侧脊髓麻醉（“半脊髓”）是一个有吸引力的概念，被认为具有上述优点以及部分保留一侧肢体感觉的额外益处。本研究结果严重质疑了这一理论概念。感觉阻滞缺乏侧间差异的最可能原因是依赖侧脑脊液中高压局麻药浓度高，当患者转为仰卧位时，会转移到先前的非依赖侧，随后导致显著阻滞。
