喉部顯微手術後是否需要Edrophonium作為肌肉鬆弛劑Mivacurium的逆轉劑之探討

Reversal of Mivacurium Chloride: Edrophonium of Spontaneous Recovery in Microscopic Laryngeal Surgery

背景：本實驗採取雙盲及隨機設計，比較在喉部顯微手術中使用mivacurium滴注作為肌肉鬆弛劑之病人，術後是否需要edrophonium來當作逆轉劑。神經肌肉阻斷計量則是以刺激尺神經之train of four來評估。方法：在取得病人及人體試驗委員會之同意後，四十位接受喉部顯微手術之病人隨機分為兩組，在手術結束後立刻停止mivacurium滴注，待肌肉組斷T1回復至10％時，在雙盲的條件下，第一組給與edrophponium與atropine；第二組則給與安慰劑，紀錄兩組之平均滴注速度，回復指數(RI50，RI75)，拔管時間，以及離開恢復室的時間。在恢復室時的噁心嘔吐及心律不整也被紀錄下來。結果：兩組之間的基本資料無顯著差異。第一組病人的神經肌肉恢復指數(RI50，RI75)明顯的較第二組縮短約兩分鐘。但是在平均滴注速度、拔管時間、噁心嘔吐、以及離開恢復室的時間則沒有統計上的差異。然而心跳過快與心率不整則是第一組明顯的較多。結論：Mivacurium因為是短效的肌肉鬆弛劑，很適合使用在喉部的顯微手術。雖然本實驗使用edrophonium當作拮抗劑可縮短約2分鐘的恢復時間；但是無論在拔管或離開恢復室時間方面均無差異；與其可能造成的嚴重併發症比較，區區2分鐘的節省是微不足道的。因此，在喉部的顯微手術後，無論就費用或危險性方面，本實驗都不推薦常規使用edrophonium作為逆轉劑。

Background: A double-blind, randomized study was designed to compare the recovery manner of mivacurium infusion with or without edrophonium reversal in microscopic laryngeal surgery. Neuromuscular blockade was quantified using the train-of-four stimuli to the ulnar nerve and quantification of the ratio of the fourth twitch to the first twitch. Methods: With the approval of the Human Studies Committee of the Taipei Veterans General Hospital and patient informed consent, 40 healthy (ASA I or II) patients with age from 24 to 54 years, undergoing microscopic laryngeal surgery were randomly selected for study. Mivacurium chloride 0.2 mg/kg was given intravenously, and then it was given in continuous infusion to maintain muscle relaxation at 90% twitch block during the procedure. At the end of operation, mivacurium infusion was terminated. In a double-blind manner, group I patients (n = 20) received intravenous edrophonium 1 mg/kg and atropine 0.01 mg/kg for reversal when T1 was at 10% recovery whereas patients in Group II (n = 20) received placebo in the same manner. Mean infusion rate, recovery index (RI50, time from T1 25% to T1 50%; RI75, time from T1 25% to T1 75%), extubation time, and discharge time between groups were compared. Nausea, vomiting, and dysrhythmias were also documented until the patient was discharged from hospital. Results: The demographic data between two groups were similar. The recovery index (RI75) for group I was shorter than that of placebo group (5.3 ± 2.19 min vs. 7.3 ± 0.9 min) and the difference was statistically significant (P = 0. 017). There were no statistically significant differences in mean infusion rate, incidence of nausea and vomiting, and discharge time from the POR. The incidence of tachycardia or arrhythmia in group I was significantly greater than that in group placebo. Conclusions: Mivacurium, a short-acting nondepolarizing agent, is a suitable muscle relaxant for patients receiving microscopic laryngeal surgery. Recovery time with the use of edrophonium as reversal agent was shorter than with placebo, but extubation and discharge time did not differ in two groups. The time which could be saved by the use of edrophonium for reversal of mivacurium to hasten the maximal recovery appears to be less than a few minutes. Therefore, clinically, the value of routine use of edrophonium to obtain a faster recovery does not outweigh its demerits of cost and risk and is not worthy of recommendation.