不同流速经鼻湿化快速充气通气联合无创通气对肥胖患者全麻诱导期胃进气的影响

Gastric insufflation related to transnasal humidified rapid-insufflation ventilatory exchange at different flow rates combined with non-invasive ventilation for intubation during induction of general anaesthesia in obese patients

目的通过胃窦超声检查评估不同流速经鼻湿化快速充气通气(THRIVE)联合无创通气(NIV)在全麻诱导时对肥胖患者胃进气的影响。方法选择择期全麻手术患者72例,男29例,女43例,年龄18-64岁,BMI 30.0-39.9 kg/m^(2),ASAⅠ或Ⅱ级。随机分为三组:H30组、H50组、H70组,每组24例。三组均行THRIVE 30 L/min预给氧5 min后行全麻诱导。全麻诱导后三组分别接受相应氧流量大小(30、50、70 L/min,FiO_(2)100%)的THRIVE联合NIV(10 cmH_(2)O)行压力控制给氧。气管插管期,各组继续行对应流速THRIVE以提供窒息氧合。入室时以及诱导通气结束时,采用超声监测患者仰卧位胃窦部进气情况,超声图像出现“彗尾征”则定义为胃进气阳性(GI^(+))。记录全麻诱导期GI^(+)的发生情况;记录入室时以及诱导通气结束时的胃窦部横截面积(CSA);记录插管过程中SpO_(2)最低值以及诱导通气结束时PaO_(2)、PaCO_(2)、P_(ET)CO_(2)等呼吸参数;记录术后恶心呕吐、反流误吸、鼻咽部不适和气压伤等不良事件的发生情况。结果全麻诱导期H70组GI^(+)发生率明显高于H30组、H50组(P<0.05)。与入室时比较,诱导通气结束时H70组胃窦部CSA明显增大(P<0.05)。诱导通气结束时H70组CSA明显大于与H30组、H50组(P<0.05)。插管过程中H50组、H70组SpO_(2)最低值明显高于H30组(P<0.05);诱导通气结束时H50组、H70组PaO_(2)明显高于H30组,PaCO_(2)明显低于H30组(P<0.05)。三组恶心呕吐发生率差异无统计学意义。三组均无一例反流误吸、鼻咽部不适和气压伤。结论THRIVE 50 L/min联合NIV 10 cmH_(2)O压控给氧能为肥胖患者全麻诱导期提供较好的氧合,且明显降低胃进气发生率。

Objective To evaluate the effects of gastric insufflation related to transnasal humidified rapid-insufflation ventilatory exchange(THRIVE)at different flow rates combined with noninvasive ventilation(NIV)for intubation during induction of general anaesthesia in obese patients under ultrasound.Methods Seventy-five patients undergoing elective operation under general anesthesia,29 males and 43 females,aged 18-64 years,BMI 30.0-39.9 kg/m^(2),ASA physical statusⅠorⅡ,were enrolled and randomly allocated into three groups(n=25):group H30,group H50,and group H70.All the patients in the above three groups underwent general anesthesia induction after pre-oxygenation for 5 minutes though THRIVE at a set oxgen flow rate of 30 L/min.During the induction period of general anesthesia,the three groups of patients received THRIVE with oxygen flow of 30 or 50 or 70 L/min and FiO_(2)=100%combined with NIN(10 cmH_(2)O)for pressure controlled oxygen administration.During intubation,each group continued with THRIVE at the corresponding flow rate to obtain apnoeic oxygenation.All patients were monitored by ultrasound at entry of the operation room and at the end of the ventilation.“Comet-tail artifacts”presented in the ultrasound image were defined as positive gastric insufflation(GI^(+)).The incidence of GI^(+) during the observation of the whole proess of general anesthesia induction and the value of the cross-sectional area(CSA)at entry of the operation room and at the end of the ventilation were recorded.PaO_(2),PaCO_(2),and P_(ET)CO_(2) at the time of last ventilation before intubation were recorded.Besides,the incidence of postoperative adverse events such as nausea,vomiting,reflux aspiration,nasopharyngeal discomfort,and barotrauma were also recorded.Results During induction of general anesthesia,the incidence of GI^(+)in group H70 was significantly higher than that in groups H30 and H50(P<0.05).CSA in group H70 was significantly increased at the end of the ventilation compared with that at entry of the operating room.At the end of the ventilation,the CSA in group H70 increased significantly compared with that in groups H30 and H50(P<0.05).During intubation,the lowest value of SpO_(2) in groups H50 and H70 was significantly higher than that in group H30(P<0.05).In groups H50 and H70,the PaO_(2) was significantly higher and the PaCO_(2) was significantly lower than that in group H30 at the end of the induction(P<0.05).There was no significant difference in the incidence of nausea and vomiting among the three groups.There was no reflux aspiration,nasopharyngeal discomfort,and barotrauma in all three groups.Conclusion THRIVE at a flow rate of 50 L/min combined with NIV at a pressure of 10 cmH_(2)O for pressure-controlled oxygen administration can provide obese patients better oxygenation during the induction period of general anesthesia without increasing the incidence of gastric insufflation.