評估經由腰椎往尾端或頭端置入導管對於硬脊膜外麻醉的影響

Evaluation of the Effects of Caudal or Cephalic Epidural Catheterization on the Characteristics of Lumbar Epidural Anesthesia

背景：作硬脊膜外麻醉時，通常會因為較粗大的薦椎神經而導致延遲或不完全的感覺阻斷。 曾經有研究顯示，朝尾端注射局部麻醉劑可以加強薦椎神經的麻醉效果。本研究的目的在探 計，對於感覺神經由薦椎神經所支配之部位的手術，經由腰椎將硬脊膜外導管朝尾端或頭端 置入之硬脊膜外麻醉的麻醉效果。方法：45位接受踩部或痔瘡手術的病人隨機分成兩組。根據導管置入的方向分成朝尾端（ED） 和朝頭端（EU）兩組。在經過C-arm fluoroscopy確認後，每組包括二十位，分別是十位踝部手術 和十位痔瘡手術的病人。這兩組硬脊膜外麻醉起始時間、作用時間、恢復時間及手術期間病 人需要額外止痛的比率被記錄並比較。結果：ED和EU這兩組在病人的年齡、身高、體重和性別方面並沒有統計上的差異。在起始、作用和恢復時間以及麻醉高度上，兩組同樣沒有統計上的差異。碓然在EU這組 期間需要額外止痛的人數比ED這組多，但同樣沒有統計學上的差異。結論：對感覺神經範圍由薦椎神經所支配部位的手術，當掾行腰椎硬脊膜外麻醉時，經 尾端或朝頭端硬脊膜外導管注射局部麻醉劑，並不能改變硬脊膜外麻醉起始、作用的時 麻醉高度、止痛作用等硬脊膜外麻醉的特性及效果。

Background: The delayed and incomplete sensory block of the sacral roots in epidural anesthesia often results from too huge the size of the first sacral nerve root. To overcome the problem, the enhancement of anesthetic effect on the sacral segment by injecting the local anesthetic toward the caudal direction has been reported. Thus, in this study, we compared the anesthetic effects of epidural anesthesia by catheterization toward caudal direction with that toward cephalic direction on the areas innervated by the sacral nerve roots. Methods: The study enrolled 45 ASA physical status I or II patients scheduled for ankle surgery or hemorrho-idectomy who were randomly and evenly divided into two groups. The epidural catheter was placed either cepha- lad (EU group) or caudad (ED group) and confirmed by C-arm fluoroscopy after catheter insertion. Each group finally consisted of 10 patients for ankle surgery and 10 for hemorrhoidectomy after exclusion of the ineligibles. The onset time, duration of, and recovery time from epidural anesthesia, as well as demand of intra-operative anal-gesic in the two groups were recorded and compared. Results: No significant differences were noted in the patients’ characteristics between the two groups. There were also no statistically significant differences in onset, duration, recovery time, and anesthetic level attained be-tween the two groups. More patients in the EU group demanded analgesics during surgery than did patients in the ED group. However, there were no statistically significant differences in the rate of analgesic demand between the two groups. Conclusions: Epidural injection of local anesthetic via catheter oriented caudad or cephalad did not change the characteristics of epidural anesthesia including onset time, duration, anesthetic level, and analgesic effect on the surgical areas innervated by the sacral roots.