Fernandez-Galinski S M, Monells J, Espadaler J M, Pol O, Puig M M
Department of Anesthesiology, Hospital Universitario del Mar, Barcelona, Spain.
Acta Anaesthesiol Scand. 1996 Jan;40(1):39-46. doi: 10.1111/j.1399-6576.1996.tb04386.x.
Although the effects of local anaesthetics (LA) on motor and sensory transmission in the spinal cord have been described, the effects of opioids are controversial. Our aim was to evaluate the action of clinically relevant doses of subarachnoid (SA) meperidine (MP) and fentanyl (FN), on somatosensory (SSEP) and cortical motor evoked responses (CMER) in awake subjects. Thirty ASA I-II patients scheduled for infra umbilical surgery received SA (N = 10/group): 1 mg/kg lidocaine (LD), 1 mg/kg MP or 25 mu g FN. SSEP elicited by stimulation of the posterior tibial nerve at the ankle, and cortical motor evoked response at rest (r-CMER) and during facilitation (f-CMER) were obtained prior and 30 min after treatment. Conduction at the proximal segment of the motor nerve (F-wave) was evaluated by stimulation of the posterior tibial nerve at the popliteal fossa. Motor/sensory block and side effects were clinically assessed. LD completely abolished SSEP and CMER. At the same dose, MP abolished SSEP in 40% of the patients, while r-CMER and f-CMER were absent in 70% and 30%, respectively; in addition, the F-wave was absent in 50% of the patients. Fentanyl induced small changes in the latencies of SSEP and F-wave; however, a 28% decrease in the amplitude of the f-CMER (P<0.05) was observed. Pruritus was present in 60% of patients in the FN group (P<0.006). Our results show that while LD and MP block sensory and motor conduction at the spinal roots, FN seems to decrease the excitability of the spinal interneurons in the corticospinal tract.
尽管局部麻醉药（LA）对脊髓运动和感觉传导的影响已有描述，但阿片类药物的影响仍存在争议。我们的目的是评估临床相关剂量的蛛网膜下腔（SA）哌替啶（MP）和芬太尼（FN）对清醒受试者体感诱发电位（SSEP）和皮层运动诱发电位（CMER）的作用。30例计划进行脐下手术的ASA I-II级患者接受SA治疗（N = 10/组）：1 mg/kg利多卡因（LD）、1 mg/kg MP或25μg FN。在治疗前和治疗后30分钟，分别记录刺激踝部胫后神经诱发的SSEP、静息时的皮层运动诱发电位（r-CMER）和易化时的皮层运动诱发电位（f-CMER）。通过刺激腘窝处的胫后神经评估运动神经近端节段的传导（F波）。临床评估运动/感觉阻滞和副作用。LD完全消除了SSEP和CMER。相同剂量下，MP使40%的患者SSEP消失，而r-CMER和f-CMER分别在70%和30%的患者中消失；此外，50%的患者F波消失。芬太尼使SSEP和F波潜伏期发生微小变化；然而，观察到f-CMER波幅下降了28%（P<0.05）。FN组60%的患者出现瘙痒（P<0.006）。我们的结果表明，虽然LD和MP阻断脊髓神经根的感觉和运动传导，但FN似乎降低了皮质脊髓束中脊髓中间神经元的兴奋性。
