探讨不同体位喉罩充气容积与气囊内压的变化

目的探讨仰卧位与俯卧位喉罩套囊不同充气容积时气囊内压的变化。方法择期行腰椎手术的患者40例(男24例,女16例),年龄22⁶7岁,体重5067岁,体重50⁷0 kg,BMI<30 kg/m2,ASA分级Ⅰ70 kg,BMI<30 kg/m2,ASA分级Ⅰ^Ⅱ级。麻醉诱导后置入4号Supreme喉罩,分别测量仰卧位(A组)与俯卧位(B组)套囊充气容量范围为5Ⅱ级。麻醉诱导后置入4号Supreme喉罩,分别测量仰卧位(A组)与俯卧位(B组)套囊充气容量范围为5³0 ml(每5 ml递增)时套囊内压及气道峰压并记录相对应的实际潮气量。记录喉罩拔出过程中恶心呕吐、呛咳、误吸、低氧血症和喉罩四周血迹程度的情况;术后24 h内患者咽喉疼痛、声音嘶哑、吞咽困难等发生情况。结果充入相同容量的气体时,A组的气道峰压和气囊内压要明显低于B组(P<0.05)。仰卧位套囊充气容量为1530 ml(每5 ml递增)时套囊内压及气道峰压并记录相对应的实际潮气量。记录喉罩拔出过程中恶心呕吐、呛咳、误吸、低氧血症和喉罩四周血迹程度的情况;术后24 h内患者咽喉疼痛、声音嘶哑、吞咽困难等发生情况。结果充入相同容量的气体时,A组的气道峰压和气囊内压要明显低于B组(P<0.05)。仰卧位套囊充气容量为15²5 ml时,气囊内压为(23.5±3.1)25 ml时,气囊内压为(23.5±3.1)^(46.3±4.5)cmH2O,有92.5%(46.3±4.5)cmH2O,有92.5%¹00%的患者实际潮气量达到90%设定潮气量;充气容量为30 ml时,气囊内压为(64.5±5.5)cmH2O,大于推荐的60 cmH2O气囊内压。俯卧位套囊充气容量为15100%的患者实际潮气量达到90%设定潮气量;充气容量为30 ml时,气囊内压为(64.5±5.5)cmH2O,大于推荐的60 cmH2O气囊内压。俯卧位套囊充气容量为15²0 ml时,气囊内压为(31.8±3.7)20 ml时,气囊内压为(31.8±3.7)^(50.2±3.0)cmH2O,有95%(50.2±3.0)cmH2O,有95%¹00%的患者实际潮气量达到90%设定潮气量;充气容量为25 ml时,气囊内压为(67.0±6.6)cmH2O,大于推荐的60 cmH2O。喉罩拔出过程中所有患者均未发生恶心呕吐、呛咳、误吸,有1例拔出喉罩后有低氧血症,有2例拔出喉罩后,喉罩带血;术后24 h所有患者均未有声音嘶哑及吞咽困难,有1例术后有咽喉疼痛。结论俯卧位喉罩所需的充气容量明显减少,且在相同充气容积时俯卧位的囊内压明显高于仰卧位,在临床工作中需根据实际体位选择最合适的充气容量。

Investigate the variation of cuff volume and intracuff pressure in different position

Objective To explore the intracuff pressure （ICP） of a laryngeal mask airway （LMA） with different cuff volume both in the prone positions and in the supine position. Methods Forty （male 24, female 16） ASA Ⅰ-Ⅱ patients, aged 22 to 67, weighing 50-70 kg, BMI〈30 kg/m2, scheduled for elective lumbar surgery, were included in the study. General anesthesia was induced and then a size 4 deflated LMA was inserted. Measured the intracuff pressure and airway peak pressure of LMA inflated with 5-30 ml （on the increase of 5 ml） of air both in supine （group A） and prone （group B） position and then recorded the corresponded actual tidal volume （Vat）. Nausea vomiting, choking, aspiration, hypoxemia and the extent of blood around the laryngeal mask were noted, alongside with sore throat, hoarseness, difficulty swallowing within 24 hours after surgery. Results Inflated with the same volume of air, both airway peak pressure and ICP in group A were lower than those in group B （P〈0.05）. In group A, when cuff volume was 15-25 ml, ICP was （23.5±3.1）-（46.3±4.5）cmH2O and actual tidal volume of 92.5%-100% patients reached 90% set tidal volume; when cuff volume was 30ml, ICP was （64.5±5.5） cmH2O and more than recommended 60 cmH2O. In group B When cuff volume was 15-20 ml, ICP was （31.8±3.7）-（50.2±3.0）cmH2O and actual tidal volume of 95%-100%patients reached 90%set tidal volume;when cuff volume was 25 ml, ICP was （67.0±6.6）cmH2O and more than recommended 60 cmH2O. During removing the LMA, all patients had no nausea and vomiting, choking, and aspiration, there was one case of hypoxia and two cases with blood staining on the LMA after its removal;all patients were no dysphonia and dysphagia and one case of postoperative sore throat pain 24 hours after operation. Conclusion The cuff volume is significantly reduced in prone position, the intracuff volume is obviously higher in prone position than that in supine position with the same cuff volume. It is needed to select the