Ghai Babita, Sethi Sameer, Ram Jagat, Wig Jyotsna
Department of Anesthesia, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
Paediatr Anaesth. 2013 Feb;23(2):122-6. doi: 10.1111/pan.12023. Epub 2012 Sep 18.
Clinical end points are often used to guide inflation and adequacy of cuff seal after laryngeal mask airway placement. However, clinical end points for cuff inflation have been shown to have significantly higher intracuff pressure. The adjusted cuff pressure between 55 and 60 cm H(2)O causes significantly better seal of laryngeal mask airway. We prospectively assessed the cuff pressures generated by cuff inflation guided by clinical end points, and the actual volume of air required to achieve cuff pressures between 55 and 60 cm H(2)O for sizes 1-2.5 reusable classic laryngeal mask airway.
Two hundred and three ASA I and II children undergoing elective cataract surgery requiring general anesthesia receiving laryngeal mask airway sizes 1-2.5 were recruited to this study. The laryngeal mask airway was placed using standard technique. After insertion of laryngeal mask airway, the cuff was slowly inflated until a slight outward shift of device was noted. Cuff pressures were measured using calibrated hand held Portex Cuff Inflator Pressure Gauge (Portex Limited, Hythe, Kent, UK). If the cuff pressure was >60 cm H(2)O, the cuff was deflated to achieve a cuff pressure of 55-60 cm H(2)O. The volume of air required to achieve this pressure was recorded.
The volume of air required to achieve the pressure between 55 and 60 cm H(2)O in laryngeal mask airway size 1, 1.5, 2.0, and 2.5 were 2.750 ± 0.2565, 4.951 ± 0.5378, 6.927 ± 0.6328, and 10.208 ± 1.4535 ml, respectively. The difference between the initial and the final cuff volumes and pressures in all laryngeal mask airway sizes were statistically significant(P = 0.000).
Lower cuff volumes are required to achieve a pressure of 60 cm H(2)O than those required if clinical end points are used as a sole guide for determining cuff inflation for patients receiving pediatric laryngeal mask airways.
临床终点常被用于指导喉罩气道置入后套囊充气及密封的充分性。然而，已表明用于套囊充气的临床终点会使套内压力显著更高。55至60 cm H₂O之间的调整后套囊压力能使喉罩气道的密封效果显著更佳。我们前瞻性地评估了由临床终点指导套囊充气所产生的套囊压力，以及1至2.5号可重复使用经典喉罩气道达到55至60 cm H₂O套囊压力所需的实际空气量。
招募了203例接受择期白内障手术且需全身麻醉、使用1至2.5号喉罩气道的美国麻醉医师协会（ASA）分级为I级和II级的儿童参与本研究。采用标准技术置入喉罩气道。插入喉罩气道后，缓慢给套囊充气，直至观察到装置有轻微向外移位。使用校准的手持式Portex套囊充气压力计（Portex有限公司，英国肯特郡海斯）测量套囊压力。如果套囊压力>60 cm H₂O，则将套囊放气以达到55至60 cm H₂O的套囊压力。记录达到该压力所需的空气量。
1号、1.5号、2.0号和2.5号喉罩气道达到55至60 cm H₂O压力所需的空气量分别为2.750±0.2565、4.951±0.5378、6.927±0.6328和10.208±1.4535 ml。所有喉罩气道尺寸的初始和最终套囊容积及压力之间的差异具有统计学意义（P = 0.000）。
对于接受小儿喉罩气道的患者，与将临床终点作为确定套囊充气的唯一指导相比，达到60 cm H₂O压力所需的套囊容积更低。
