極低流量活寧(Isoflurane)麻醉在冠狀動脈繞道手術中不但可以防止病人高血糖且有利於術中循環與代謝的恆定

Minimal Low-flow Isoflurane-based Anesthesia Benefits Patients undergoing Coronary Revascularization via Preventing Hyperglycemia and Maintaining Metabolic Homeostasis

背景：極低流量(minimal low-flow)麻醉技術已廣泛的應用在臨床麻醉上。本實驗以isoflurane為主要麻醉劑，極低流量為全身麻醉。此方法適用於心臟功能不佳，且需進行冠狀動脈繞道手術的病人。我們推論此麻醉方式可以促進病人手術中的血循環動力學與身體代謝之恆定，與加速術後復原，血管循環系統和代謝恆定達到較佳的麻醉恢復。方法：針對一百零七位常規冠狀動脈繞道手術的病人進行分組實驗。其中五十四人接受以isoflurane為主的極低流量全身麻醉；另外五十三人接受以fentanyl為主的傳統麻醉技術為對照組，比較兩組病人術後升壓劑的使用量，與手術後恢復速度。結果：接受以isoflurane為主的極低流量麻醉之病人，其術後需要升壓劑支持的使用量、病人術後需要持續氣管留滯時間及加護中心停留天數，比fentanyl為主的麻醉對照組明顯減低。在手術中進行體外循環期，以fentanyl為主的傳統的麻醉技術病患，迫切需要矯正酸中毒與高血糖的情形，遠較於極低流量麻醉組增加。結論：以isoflurane為主的極低流量麻醉可以安全的適用在「冠狀動脈繞道手術的病人」且比fentanyl為主的傳統的麻醉更易達到迅速手術後復原，手術中的血循環動力學與身體代謝的恆定表現，正是說明此極低流量麻醉有利病人手術後恢復，也許具有心肌保護的特殊作用，值得進一步探討。

Background: The objectives of this study were to determine whether minimal low-flow isoflurane-based anesthesia could be a feasible technique for patients undergoing coronary artery bypass graft surgery. It is hypothesized that isoflurane-based anesthesia facilitates an agreeable recovery from surgery is mediated through preventing hyperglycemia and metabolic disturbance associated with cardiopulmonary bypass. Methods: 107 consecutive patients were randomly assigned to two groups, i.e., isoflurane-based anesthesia group (n = 54) and fentanyl-based anesthesia group (control group, n = 53). In isoflurane-based anesthesia group, patients received isoflurane from induction up till departure from operating room to intensive care unit (ICU). In the control group, fentanyl (66.4 ± 3.2 μg/kg) and midazolam (320 ± 20 μg/kg) were administered to anesthetize the patients during the operation. Results: Patients with isoflurane-based anesthesia required less dopamine (0.6 ± 0.2 vs. 4.2 ± 0.4 μg/min) and dobutamine (0.4 ± 0.2 vs. 4.1 ± 0.5 μg/min); they could be extubated earlier (7.9 ± 1.0 vs. 35.1 ± 2.9 h), and had a shorter stay at ICU (2.2 ± 0.2 vs. 4.8 ± 0.4 days). In addition, occurrence of hyperglycemia (167 ± 7.7 vs. 243 ± 9.5 mg/dl) and bicarbonate requirement (128 ± 7.0 vs. 313 ± 22.0 mEq) were less in patients with isoflurane-based anesthesia as compared with those in fentanyl group. Conclusions: These results demonstrate that isoflurane, not fentanyl, benefits patients undergoing coronary artery bypass grafting surgery. This benefit perhaps is mediated through maintaining hemodynamic stability and metabolic homeostasis and preventing hyperglycemia.