以聽覺誘發電位(AEP)做為麻醉時插管的指標

Utility of the Auditory Evoked Potentials index as an Indicator for Endotracheal Intubation

背景：聽覺誘發電位（AEP）已被廣泛用來當做麻醉深度的指標之一。這個實驗是要來比較使用AEP當做插管指標及依臨床經驗來做插管，在血行動力學上是否有所差異。方法：本實驗共104位病人。在對照組中，麻醉醫師依個人經驗做插管，實驗組依不同的AAI值（15, 20, 30）做為插管指標。麻醉誘導時給予cisatracurium, lidocaine, fentanyl, thiamylal and succinylcholine等藥物，分別在休息時、插管前一分鐘、插管後一分鐘及三分鐘測量心跳及血壓，如果插管前、後一分鐘心跳血壓的變化超過20％，則定義為嚴重變化。結果：在AAI-15及AAI-20這兩組的心跳、血壓產生嚴重變化的機率比對照組是明顯的要低（19％ and 39％ vs. 68％，P < 0.01and 0.05；52％ and 52％ vs.91％，P < 0.01）。而誘導時間在對照組比起實驗組則是短了 許多（183 ± 47 vs. 366 ± 151, 248 ± 53，and 255 ± 85 sec, P < 0.01）。在 AAI-15這組所需的thiamylal劑量及誘導時間是最高和最長的。結論：和醫師個人經驗比較起來，插管時以AEP當做輔助指標會使心跳血壓較穩定，而AAI-20是一不錯的插管指標。

Background: The A-line ARX Index (AAI) has been used as an indicator of depth of anesthesia. The study examined whether AAI-guided endotracheal intubation (El), compared with experience guidance, could provide better hemodynamic stability during general anesthesia (GA). Methods: One hundred and four patients were included in this study. In the control group, El was performed based on the judgment of the anesthesiologist by clinical experience. In the study groups, El was performed at an AAI value of either 15, 20, or 30. GA was induced with cisatracurium, lidocaine, fentanyl, thiamylal and succinylcholine. Heart rate (HR) and mean arterial pressure (MAP) were recorded at baseline, 1 min before and 1 and 3 min after intubation. The change of hemodynamics over 20% in the space between 1 min before and after intubation was defined as severe change. Results: The incidences of severe changes of HR and MAP in the AAI-15 and AAI-20 groups were significantly lower than those in the control group (19% and 39% vs. 68%, P < 0.01 and 0.05; 52% and 52% vs, 91%, P < 0.01, respectively). The induction time was significantly shorter in the control group than that in the study groups (183 ± 47 vs. 366 ± 151, 248 ± 53, and 255 ± 85 sec, P < 0.01). Highest dose of thiamylal and longest induction time were needed in the AAI-15 group. Conclusions: Compared with the routine clinical practice, AAI monitoring helps to achieve better condition for El during induction with less hemodynamic changes. The AAI value of 20 is suggested as an optimal indicator for El.