Carpenter R L, Hogan Q H, Liu S S, Crane B, Moore J
Department of Anesthesiology, Bowman Gray School of Medicine at Wake Forest University, Winston-Salem, North Carolina, USA.
Anesthesiology. 1998 Jul;89(1):24-9. doi: 10.1097/00000542-199807000-00007.
BACKGROUND. Injection of local anesthetic into cerebrospinal fluid (CSF) produces anesthesia of unpredictable extent and duration. Although many factors have been identified that affect the extent of spinal anesthesia, correlations are relatively poor and the extent of spread remains unpredictable. This study was designed to determine whether variability in the volume of lumbosacral CSF among individuals is a contributing factor in the variability of spinal anesthesia.
Spinal anesthesia was administered to 10 healthy volunteers with 50 mg lidocaine in 7.5% dextrose. The technique was standardized to minimize variability in factors known to affect the distribution of spinal anesthesia. The extent of sensory anesthesia was assessed by pin-prick and by transcutaneous electrical stimulation. Motor blockade was assessed in the quadriceps and gastrocnemius muscles by force dynamometry. Duration of anesthesia was assessed by pinprick, transcutaneous electrical stimulation, and duration of motor blockade. Lumbosacral CSF volumes were calculated from low thoracic, lumbar, and sacral axial magnetic resonance images obtained at 8-mm increments. Volumes of CSF were correlated with measures of extent and duration of spinal anesthesia using the Kendall rank correlation test.
Lumbosacral CSF volumes ranged from 42.7 to 81.1 ml. Volumes of CSF correlated with pin-prick assessments of peak sensory block height (P = 0.02) and duration of surgical anesthesia (as assessed by the duration of tolerance to transcutaneous electrical stimulation at the ankle (P < 0.05).
Variability in lumbosacral CSF volume is the most important factor identified to date that contributes to the variability in the spread of spinal sensory anesthesia.
背景。将局部麻醉药注入脑脊液（CSF）会产生范围和持续时间不可预测的麻醉效果。尽管已确定许多影响脊髓麻醉范围的因素，但相关性相对较差，麻醉扩散范围仍然不可预测。本研究旨在确定个体腰骶部脑脊液体积的变异性是否是脊髓麻醉变异性的一个促成因素。
对10名健康志愿者给予50mg利多卡因加7.5%葡萄糖进行脊髓麻醉。该技术标准化以尽量减少已知影响脊髓麻醉分布的因素的变异性。通过针刺和经皮电刺激评估感觉麻醉范围。通过测力计评估股四头肌和腓肠肌的运动阻滞。通过针刺、经皮电刺激和运动阻滞持续时间评估麻醉持续时间。根据以8mm增量获得的低胸段、腰段和骶段轴向磁共振图像计算腰骶部脑脊液体积。使用肯德尔等级相关检验将脑脊液体积与脊髓麻醉范围和持续时间的测量值进行相关性分析。
腰骶部脑脊液体积范围为42.7至81.1ml。脑脊液体积与针刺评估的感觉阻滞峰值高度（P = 0.02）和手术麻醉持续时间（通过踝关节对经皮电刺激的耐受时间评估，P < 0.05）相关。
腰骶部脑脊液体积的变异性是迄今为止确定的导致脊髓感觉麻醉扩散变异性的最重要因素。
