超声实时监测颈部食管进气在全身麻醉诱导期的应用

Real-time monitoring of cervical esophageal insufflation by ultrasound during induction of general anesthesia

目的通过超声实时监测全身麻醉诱导期颈部食管进气情况并及时调整面罩通气压力,探讨减少胃内进气的效果。方法择期接受全身麻醉的手术患者60例,男33例,女27例,年龄25~65岁,BMI 19~28 kg/m^2,ASAⅠ或Ⅱ级。随机分为研究组(S组)和对照组(C组),每组30例。全身麻醉诱导期采用压力控制模式进行面罩通气,两组的起始通气压力为15 cmH2O。S组采用高频超声探头观察颈部食管进气情况,及时降低通气压力,直至未发现食管进气为止;C组通气压力维持15 cmH2O。两组均采用低频超声探头观察并测量麻醉诱导前后胃窦部横截面积(CSA),机械通气2 min后进行气管插管,记录通气前后胃窦部CSA。记录通气结束后胃内进气情况,末次通气时气道峰压(Ppeak)、呼出潮气量(VTe)、呼气末二氧化碳(PETCO2)和呼气末氧浓度(CETO2)。结果通气结束后,S组胃进气发生率明显低于C组(P<0.01)。末次通气时S组Ppeak、VTe、CETO2明显低于C组(P<0.01),PETCO2明显高于C组(P<0.01)。通气结束后S组CSA明显小于C组(P<0.01)。结论麻醉诱导期间面罩压力通气时,通过超声实时监测颈部食管进气情况并及时调整面罩通气压力,可明显减少胃内进气的发生率。

Objective To explore the effect of real-time monitoring of cervical esophageal insufflation during the induction period of general anesthesia by ultrasonography and timely adjustment of mask ventilation pressureon reducing gastric insufflation.Methods Sixty patients,33 males and 27 females,aged 25-65 years,BMI 19-28 kg/m ^2,falling into ASA physical statusⅠorⅡ,about to undergo elective surgery under general anesthesia,were randomly divided into study group(group S)and control group(group C),with 30 patients in each group.During the induction period of general anesthesia,pressure control mode was used for mask ventilation.The initial ventilation pressure of the two groups was 15 cmH 2O.In group S,high-frequency ultrasound probe was used to observe the cervical esophageal insufflationtimely,and reduce the ventilation pressure accordingly,until no esophageal insufflations was observed.While in group C,the ventilation pressure of face mask was maintained at 15 cmH 2O.The cross sectional area(CSA)of gastric antrum before and after induction of general anesthesia was observed and measured by low-frequency ultrasound probe in both groups.The tracheal intubation was performed 2 min after mechanical ventilation.Gastric insufflation,peak of pressure(Ppeak)at the last time of the pressure ventilation,exhaled tidal volume(VTe),end-expiratory partial pressure of carbon dioxide(P ET CO 2),end-expiratory oxygen concentration(C ET O 2)and CSA of gastric antrum of each subject were recorded.Results After ventilation,the incidence of gastric insufflation in group S was significantly lower than that in group C(P<0.01).At the last time of ventilation,the Ppeak,VTe and C ET O 2 in group C were significantly higher than those in group S(P<0.01),while the P ET CO 2 in group C was significantly lower than that in group S(P<0.01).After ventilation,the CSA of gastric antrum in group S was obviously smaller than that in group C(P<0.01).Conclusion During the induction period of general anesthesia with mask pressure ventilation,the real-time monitoring of cervical esophageal insufflation by ultrasound and timely adjustment of mask ventilation pressure can significantly reduce the incidence of gastric insufflation.