本研究结果可能与以下因素有关: ILMA引导气管插管操作包括插入ILMA、气管插管和拔除ILMA三个步骤,因此操作时间相对较长。本研究中ILMA组的气管插管时间[(91.84±8.58)s] 明显长于喉镜组[(28.52±9.66)s],从而使得心血管反射增强。与直接喉镜操作相比较,采用ILMA引导气管插管操作对口咽部黏膜和颈椎施加的压力较大,甚至超过了咽部黏膜的毛细血管灌注压并可使颈椎向后移位[15-16],因此可能产生较大的局部刺激作用。为了寻找ILMA的最佳肺通气位置以顺利插入气管导管,需采取上下提拉操作、水平移动通气导管、改变患者头颈部的位置、增加通气罩内的充气量或更换ILMA的型号等措施,从而可对口咽腔产生较大的摩擦性刺激。在进入声门之前,气管导管需要抬起ILMA的会厌提升板,以上提会厌和显露声门,从而可能对会厌及其周围组织产生一定的压迫性刺激。当气管导管的前端顶在喉前庭壁、下垂的会厌尖端或食管上端括约肌等部位时,可发生气管导管推送困难。此时需要旋转气管导管、上下调整ILMA的位置或调整患者头颈部的位置,从而可进一步增强对咽喉部的刺激。另有研究证实,与ILMA插入和引导气管插管操作相比较,气管插管成功后拔除ILMA是一种更为强烈的刺激,可产生更为明显的心血管刺激和皮肤血管舒缩反射[17]。这是因为在拔除ILMA的过程中,通气罩可与口咽腔以及气管导管可与气管壁发生较强的摩擦。而且为了防止意外性拔管,麻醉医师常采用专用稳定棒进一步推送气管导管,从而可摩擦气管壁甚至出现气管导管过深而刺激隆突的情况。 综上所述,虽然采用ILMA可以避免直接喉镜上提会厌的强烈刺激,但是该有益作用被操作过程中产生的其他伤害性刺激所掩盖,从而导致了与直接喉镜气管插管相类似的血流动力学反应。 需要注意的是,有些研究与我们的结果并不一致。Baskett等认为,采用ILMA引导气管插管可产生具有明显统计学差异而没有明确临床意义的轻度心血管反应[3]。Joo等研究发现,采用直接喉镜经口气管插管的患者在气管插管后平均动脉压明显高于采用ILMA引导气管插管的患者[4]。但是,Baskett未进行直接喉镜经口气管插管的对照研究,而Joo是在将ILMA插入5min后才开始实施气管插管操作,因此并不符合实际的临床应用情况。 总之,本研究结果显示,在全身麻醉下采用ILMA引导气管插管可产生与直接喉镜气管插管相类似的心血管反应。在日常临床麻醉工作中,对心脑血管疾病患者不建议采用ILMA来预防气管插管的心血管不良反应。<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> 参 考 文 献 1. Brain AIJ,Verghese C,Addy EV,et al. The intubating laryngeal mask,Ⅰ: Development of a new device for intubation of the trachea. Br J Anaesth,1997;79:699-703. 2. Brain AIJ,Verghese C,Addy EV,et al. The intubating laryngeal mask,Ⅱ:A preliminary clinical report of a new means of intubating the trachea. Br J Anaesth,1997;79:704-709. 3.Baskett PJF,Parr MJA,Nolan JP. The intubating laryngeal mask. Results of a multicentre trial with experience of 500 cases. Anaesthesia,1998;53:1174-1179. 4. Joo HS,Rose DK. The intubating laryngeal mask airway with and without fiberoptic guidance. Anesth Analg,1999;88:662-666. 5. Kihara S,Yaguchi Y,Watanabe S,et al. Haemodynamic responses to the intubating laryngeal mask and timing of removal. Eur J Anaesth,2000;17:744-750. 6. Kihara S,Watanabe S,Taguchi N,et al:Tracheal intubation with the Macintosh laryngoscope vs intubating laryngeal mask airway in adults with normal airways. Anaesth Intensive Care,2000;28:281-286. 7. Choyce A,Avidan MS,Harvey,et al. The The cardiovascular responses to insertion of the intubating laryngeal mask airway.Anaesthesia,2002;57:330-333. 8.Imai M,Matsumura C,Hanaoka Y,Kemmotsu O. Comparison of cardio-vascular responses to airway management:fiberoptic intubation using a new adapter,laryngeal mask insertion,or conventional laryngoscopic intubation. J Clin Anesth,1995;7:14-18. 9.Takahashi SJ,Mizutani T,Miyabe M,et al. Hemodynamic responses to tracheal intubation with laryngoscope versus lightwand intubating device (Trachlight)in adults with normal airway. Anesth Analg,2002;95:480-484. 10. Helfman SM,Gold MI,DeLisser EA,et al. Which drug prevents tachycar- dia and hypertension associated with tracheal intubation:lidocaine,fentanyl or esmolol?Anesth Analg,1991;72:482-486. 11. Kirvela M,Scheinin M,Lindgren L. Haemodynamic and catecholamine re-sponses to induction of anaesthesia and tracheal intubation in diabetic and non-diabetic uraemic patients. Br J Anaesth,1995;74:60-65. 12. Houghton IT,Low JM,Lau JTF,et al.An ethnic comparison of the sympathetic responses to tracheal intubation. Anaesthesia,1993;48:965-968. 13. Shribman AJ,Smith G,Achola KJ:Cardiovascular and catecholamine re-sponses to laryngoscopy with and without tracheal intubation. Br J Anaesth,1987;59:295-299. 14. Bucx MJ,Scheck PA,Van Geel RT,et al. Measurement of forces during laryngoscopy. Anaesthesia,1992;47:348-351. 15. Keller C,Brimacombe J. Pharyngeal mucosal pressures,airway sealing pres-sures and fiberoptic position with the intubating versus the standard laryngeal mask airway. Anesthesiology,1999;90:1001-1006. 16. Keller C,Brimacombe J,Keller K. Pressures exerted against the cervical vertebrae by the standard and intubating laryngeal mask airway:a randomized,controlled,cross-over study in fresh cadavers. Anesth Analg,1999;89:1296-1300. 17. Shimoda O,Yoshitake A,Abe E,et al. Reflex responses to insertion of the intubating laryngeal mask airway,intubation and removal of the ILMA. Anaesth Intensive Care,2002;30:766-770. |