喉罩和气管导管在经皮扩张气管造口术中的应用：气管内结构可见度的对比

目的在经皮扩张气管造口（pefcutaneous dilatational tracheostomy，PDT）过程中，由于气管结构暴露不良，导致一些严重的并发症。从主观上来说，通过喉罩（1aryngeal mask airway，LMA）行纤维支气管镜检查比通过气管导管（endotracheal tube，ETT）行纤维支气管镜检查其视野显示更充分。本前瞻性随机研究旨在比较LMA及EIT在PDT过程中，气管结构显示的清晰程度，同时报道lOT中通气质量及气道相关并发症。方法本研究中，接受PDT的患者33例使用LMA，30例使用ETT。通气质量及气管结构（甲状软骨、环状软骨、气管软骨）的可视程度分为4级：很好（1级）；较好（2级）；困难（3级）；无法通气或看见（4级）。评分为4级的患者需要更换通气方法。组间比较使用X2检验。结果LMA组的气管结构可见度更高：LMA组94％为1级或2级，而ETT组仅有66％为1级或2级（P〈0．05）。LMA组患者气管穿刺过程中97％的患者视野显示为1级或2级，而ETT组仅有77％（P〈0．05）。LMA组及ETT组分别有1例和3例患者评分为4级。两组的血流动力学变化相似。两组均存在PDT过程中Pa02的下降及PaCO2的上升，但是ETT组PaCO2的上升更为显著（59±14mmHg及51±11mmHg，P〈0．05）。ETF组2例患者气管导管不慎滑脱，另1例患者因气管穿刺位置显示不清导致纤维支气管镜损坏。结论与EIT相比，LMA在气管结构的可视程度及PUF扩张中具有明显优点。特别是对于缺乏经验的重症监护人员或是解剖结构复杂的患者而言，良好的显露使得操作条件更优化。

PURPOSE： Some severe complications during percutaneous dilatational tracheostomy （PDT） may be related to poor visualization of tracheal structures. Subjectively, the bronchoscopical view obtained via a laryngeal mask airway （LMA） seems to be better than that obtained with an endotracheal tube （ETT）. In this prospective, randomized study, we compared LMA and ETT as the ventilatory device during PDT mainly with respect to visualization of tracheal structures. The quality of ventilation and airway-related complications are also reported. METHODS： In this prospective, randomized study, PDT was performed using an LIMA （n = 33） or an ETT （n = 30）. Quality of ventilation and visualization of tracheal structures （thyroid, cricoid, and tracheal cartilages） were rated as follows： very good （1）, good （2）, difficult （3）, and not possible （4） with LMA/ETT. A rating of 4 required the alternate airway. Groups were compared using the X2 test. RESULTS： Visualization of tracheal structures was better with the LMA： ratings were i or 2 in 94% of patients with an LMA, compared with 66% of patients with an ETT （P 〈 0.05）. Visual control during puncturing the trachea was 1 or 2 in 97% of patients using an LMA and 77% of patients for an ETT （P 〈 0.05 ）. A rating of 4 was assigned to 1 patient with an LMA and to 3 patients with an ETT. Hemodynamic variables were similar in both groups. Blood gas analysis during PDT showed decreased PaO2 in both groups, and increased PaCO2, which was more pronounced with an ETT compared with an LMA （59 ± 14 mm Hg and 51 ± 11 mm Hg （P 〈0. 05 ] ）. In the EFT group, 2 patients were extubated accidentally, and in another patient, the bronchoscope was damaged because of insufficient visualization of the tracheal puncture site. CONCLUSIONS： The LMA technique showed definite advantages regarding visualization of relevant tracheal structures and the dilation process compared with an ETT. This may be especially relevant in the hands of inexperienced intensivists and in cases of difficult patient anatomy where improved structural visualization optimizes operating conditions.