呼气末正压对喉罩全麻患者颈内静脉横截面积及颈总动脉／颈内静脉解剖关系的影响

Effect of positive end-expiratory pressure on the cross-sectional area of the internal jugular vein and anatomic relationship between the internal jugular vein and the carotid artery in general anaesthesia of laryngeal mask airway

目的超声观察不同程度呼气末正压（PEEP）对喉罩全麻患者颈内静脉横截面积（CSA）和颈总动脉/颈内静脉解剖关系的影响。方法本研究为前瞻性研究，纳入2017年5至11月宁波市第二医院行择期喉罩全麻患者60例。年龄20～65岁，美国麻醉医师协会（ASA）分级Ⅰ或Ⅱ级，通过Excel软件随机分为4组：P0组（PEEP： 0 cmH2O）、P5组（PEEP： 5 cmH2O）、P10组（PEEP： 10 cmH2O）、P15组（PEEP： 15 cmH2O）。患者全麻诱导后置入Supreme喉罩并行机械通气，每次以随机顺序更换PEEP压力后1 min在固定位置获取右侧颈部超声图像。记录各组患者颈内静脉CSA、横径和前后径，颈总动脉直径，颈总动脉重叠距离和重叠率，平均动脉压（MAP），心率（HR）和血管活性药使用次数。结果P0、P10、P15组的CSA分别为（1.36±0.55）、（1.80±0.54）、（2.02±0.58） cm2；横径分别为（1.31±0.33）、（1.61±0.49）、（1.74±0.53） cm；前后径分别为（1.12±0.20）、（1.33±0.30）、（1.46±0.32） cm；与P0组比较，P10组和P15组的CSA、横径和前后径均显著增加（P0/P10：t＝7.81、3.81、4.30，均P〈0.01；P0/P15：t＝11.68、5.40、6.96，均P〈0.01）；与P10组比较，P15组的前后径和横径差异均无统计学意义（均P〉0.05），但CSA显著增加（t＝2.17，P〈0.05）。P0、P10、P15组的重叠距离为（0.51±0.12）、（0.62±0.16）、（0.66±0.15） cm；重叠率为（76.80±20.03）%、（91.10±26.13）%、（96.21±25.36）%。与P0组比较，P10组和P15组的重叠距离和重叠率均显著增加（P0/P10：t＝4.49、3.41，均P〈0.01；P0/P15：t＝5.91、4.63，均P〈0.01）；与P10组比较，P15组的重叠距离和重叠率差异均无统计学意义（均P〉0.05）。与P0组相比，P15组MAP显著降低[（73.35±9.73） vs （67.58±12.58） mmHg，t＝2.745，P〈0.05]；所有患者均未给予阿托品或去氧肾上腺素。结论应用PEEP能够有效增加喉罩全麻患者颈内静脉CSA，但同时使得颈内静脉颈总动脉重叠率上升。10 cmH2O PEEP能够在增加颈内静脉CSA和维持血流动力学稳定之间取得较好的平衡。

ObjectiveTo investigate the effect of positive end-expiratory pressure（PEEP） on the cross-sectional area （CSA） of the internal jugular vein （IJV） and anatomic relationship between the IJV and the common carotid artery （CCA） in general anaesthesia of laryngeal mask airway（LMA）. MethodsSixty American Society of Anesthesiologists （ASA） Ⅰ or Ⅱ grade patients undergoing elective operation received general anaesthesia using LMA from May to November 2017, aged 20-65, were included in this study and randomly divided into 4 groups： group P0 （PEEP： 0 cmH2O）, group P5 （PEEP： 5 cmH2O）, group P10 （PEEP： 10 cmH2O）, group P15 （PEEP： 15 cmH2O）. Following the induction of anesthesia, LMA was inserted, and mechanical ventilation was started while the right cervical vessels was imaged by ultrasonography after applying 4 different PEEPs in random order. Measurements were made after 1 min in each PEEP. The CSA, transverse diameter （TD）, anteroposterior diameters （AD） of the IJV and the diameter, overlap distance and overlap index of CCA was measured. The arterial blood pressure, heart rate, and vasoactive drugs used were also recorded. ResultsThe CSA of group P0, P10 and P15 was （1.36±0.55）, （1.80±0.54）, （2.02±0.58） cm2. The TD was （1.31±0.33）, （1.61±0.49）, （1.74±0.53） cm. The AD was （1.12±0.20）, （1.33±0.30）, （1.46±0.32） cm. Compared to group P0, the CSA, TD and AD of IJV in group P10 and P15 were significantly increased （P0/P10： t=7.81, 3.81, 4.30, all P〈0.01; P0/P15： t=11.68, 5.40, 6.96, all P〈0.01）. There was no significant difference in the AD and TD of IJV between group P10 and P15 （all P〉0.05）, while the CSA of group P15 was bigger than that of group P10 （t=2.17, P〈0.05）. The overlap distance of group P0, P10 and P15 was （0.51±0.12）, （0.62±0.16）, （0.66±0.15） cm. The overlap index was （76.80±20.03）%, （91.10±26.13）%, （96.21±25.36）%. Compared to group P0, the overlap distance and overlap index in group P10 and P15 were significantly increased （P0/P10： t=4.49, 3.41, both P〈0.01; P0/P15： t=5.91, 4.63, both P〈0.01）. There was no significant changes in the overlap distance and overlap index between group P10 and P15 （all P〉0.05）. The MAP of group P15 was lower than that of group P10 [（73.35±9.73 ）vs （67.58±12.58） mmHg, t=2.745, P〈0.05]. No patients were given atropine or norepinephrine. ConclusionsThe application of PEEP effectively increases the CSA of IJV in general anaesthesia of LMA. At the same time, it also lead to higher overlap index between the IJV and CCA.Ten cmH2O PEEP provides the best balance between the increase of CSA and the stability of haemodynamics.