Chung Y T, Lin C H, Pang W W, Yeh L T, Tien Y K
Department of Anesthesiology, Changhua Christian Hospital, Taiwan, R.O.C.
Acta Anaesthesiol Sin. 1998 Dec;36(4):221-7.
Continuous caudal block with caudad catheterization has not yet been mentioned in literatures. We designed a preliminary study to investigate the feasibleness of this technique, spread of contrast medium under fluoroscopy, and its clinical effectiveness.
Ten patients were subjected to epidural block (caudal) for elective anal or vaginal procedures. The entry of the epidural needle was made at the L4-5 interspace either with midline or paramedian approach. Through an 18 G Touhy needle with its bevel facing caudally an epidural catheter was threaded until a length of 10 cm was beyond the point of entry. The presence or absence of paresthesia during the passage of catheter and the ease with which the catheter was inserted were recorded. After the procedure, the course on which the catheter traversed and the spread of the medicinal substance in the epidural space were visualized and studied fluoroscopically using 1 and 3 ml iohexol (omnipaque 300 mg/ml) as contrast medium respectively. Then the patients were brought to operating rooms for anesthesia and surgery. Sensory anesthetic level and motor blockade were evaluated fifteen min after 11-15 ml of 2% lidocaine had been injected through the epidural catheter. During anesthesia vital signs were closely monitored, and adverse reaction if any was evaluated and managed.
The insertion of the epidural catheter was considered easy and caused no paresthesia in nine patients. Catheter insertion encountered moderate resistance and induced paresthesia in one patient. Yet, the catheter was advanced successfully to the expected length. In radiological study with contrast medium, the course of the epidural catheter was not always traceable, while the spread of the contrast medium was clearly identified. Epidural spread occurred in eight patients, left paravertebral spread in one patient, and right retrorectal spread in another one patient. As to clinical assessment, adequate sensory blockade with local anesthetic was gained in 8 patients with well-preserved motor function of the lower limbs. In one patient the caudal block worked well after the withdrawal of the catheter 5 cm in length. Spinal anesthesia was supplemented in one patient due to failure of the caudal block.
Continuous caudal block with caudawise catheterization via lower lumbar interspaces is feasible (eight of 10 patients in this study) with respect to technique and clinical effect. Paravertebral and retrorectal migrations of the catheter may occur in spite of smooth catheterization. Either migration might lead to a failure of caudal block.
文献中尚未提及连续尾端阻滞及尾端置管。我们设计了一项初步研究，以探讨该技术的可行性、透视下造影剂的扩散情况及其临床效果。
10例患者因择期肛门或阴道手术接受硬膜外阻滞（尾端）。硬膜外穿刺针经L4 - 5间隙，采用正中或旁正中入路进针。通过一根18G的斜面朝向尾端的Tuohy针，将硬膜外导管置入，使其超出穿刺点10cm。记录置管过程中有无感觉异常及置管的难易程度。术后，分别使用1ml和3ml碘海醇（欧乃派克300mg/ml）作为造影剂，通过透视观察导管走行及药物在硬膜外间隙的扩散情况并进行研究。然后将患者送入手术室进行麻醉和手术。经硬膜外导管注入11至15ml 2%利多卡因15分钟后，评估感觉麻醉平面和运动阻滞情况。麻醉期间密切监测生命体征，评估并处理任何不良反应。
9例患者硬膜外导管置入顺利，未出现感觉异常。1例患者置管时遇到中度阻力并诱发感觉异常，但导管仍成功置入预期长度。在造影剂的影像学研究中，硬膜外导管走行并非总能清晰显示，但造影剂的扩散情况清晰可辨。8例患者出现硬膜外扩散，1例患者出现左侧椎旁扩散，另1例患者出现右侧直肠后扩散。临床评估方面，8例患者获得了足够的局部麻醉感觉阻滞，下肢运动功能良好。1例患者在导管拔出5cm后尾端阻滞效果良好。1例患者因尾端阻滞失败补充了脊髓麻醉。
经下腰椎间隙向尾端置管进行连续尾端阻滞在技术和临床效果方面是可行的（本研究10例患者中有8例）。尽管置管顺利，导管仍可能出现椎旁和直肠后移位。任何一种移位都可能导致尾端阻滞失败。
