硬脊膜外注射Ropivacaine後立刻引起抽筋之病例報告

Ropivacaine-Induced Convulsion Immediately after Epidural Administration-- A Case Report

Ropivacaine是一新的長效局部麻醉劑，其毒性比bupivacaine低。我們報告一位將接受全膝關節置換術的老年女性病人，在硬脊膜外注射完160毫克ropivacaine後，立即發生抽筋的病例報告。雖然在注射前有做過回抽及試驗劑之注射，但我們仍然認為此160毫克的ropivacaine，是意外的注射到了靜脈內。發生抽筋後，在給予thiopental 150毫克及輔助呼吸後，病人意識很快的恢復，當中並沒有發生嚴重的心血管併發症。文中對ropivacaine的安全性，及發生意外靜脈注射的可能原因，有詳細之討論。

Ropivacaine is a new long-acting amide-type local anesthetic with less toxic effects compared with bupivacaine. Here, we report a case who sustained convulsion immediately after administration of epidural ropivacaine. A 75-year-old woman was scheduled for total knee replacement. Epidural catheter was inserted smoothly. After aspiration test and injection of a test dose of 3 ml of 2% lidocaine containing 15 μg epinephrine, 160 mg ropivacaine was administered epidurally. Unfortunately, a generalized tonic-clonic convulsion of sudden onset occurred right after ropivacaine injection. After he was given 100% oxygen and intravenous thiopental 150 mg, the patient recovered uneventfully. During the episode of convulsion sinus tachycardia at a rate of 120 beats/min without the interposal of other form of cardiac arrythmia was noted, and respiration remained intact. This suggests that ropivacaine offers a good cardiovascular stability. This example serves as another evidence to remind us that even with a negative aspiration following epidural catheter placement and an uneventful test dose injection, inadvertent intravascular injection may still happen, particularly in the elderly.