喷射通气频率对硬质支气管镜检查患者通气效果的影响

Effect of jet ventilation frequency on ventilation efficacy in patients undergoing rigid bronchoscopy

目的通过电阻抗断层扫描(EIT)观察喷射式呼吸机在不同喷射通气(JV)频率下对硬质支气管镜检查患者通气效果的影响。方法选择择期行硬质支气管镜检查患者90例,男42例,女48例,年龄18~60岁,BMI 18.5~27.9 kg/m^(2),ASAⅠ或Ⅱ级。采用随机数字表法将患者分为三组:低频通气组(J20组)采用20次/分的频率进行喷射通气;常频通气组(J60组)采用60次/分的频率进行喷射通气;高频通气组(J150组)采用150次/分的频率进行喷射通气,每组30例。记录麻醉诱导后通气5 min(T_(1))、手术开始5 min(T_(2))、手术结束(T_(3))时喷射通气下的吸气峰压(PIP)、平均吸气压力(MIP)、氧合指数(PaO_(2)/FiO_(2))、PaCO_(2)。并通过EIT记录T_(1)—T_(3)时肺不同区域(ROI_(1)、ROI_(2)、ROI_(3)、ROI_(4))的通气占比及阻抗值(IR)。结果与J20组比较,J60组和J150组PIP、MIP、PaO_(2)/FiO_(2)明显降低,PaCO_(2)明显升高(P<0.05),在ROI_(1)、ROI_(2)、ROI_(3)、ROI_(4)区域通气占比均明显降低(P<0.05),IR明显降低(P<0.05)。与J60组比较,J150组PIP、MIP、PaO_(2)/FiO_(2)明显降低,PaCO_(2)明显升高(P<0.05),在ROI_(1)、ROI_(2)、ROI_(3)、ROI_(4)区域通气占比均明显降低(P<0.05),IR明显降低(P<0.05)。T_(1)—T_(3)时三组肺ROI_(1)、ROI_(2)、ROI_(3)、ROI_(4)区域通气占比变化差异无统计学意义。结论硬质支气管镜检查的患者在不同喷射通气频率下肺内气体分布改变明显,150次/分的高频喷射通气可在满足氧合的前提下明显改善肺内气体分布。

Objective To observe the effect of jet ventilation(JV)at different frequencies on ventilation in patients undergoing rigid bronchoscopy by electrical impedance tomography(EIT).Methods Ninety patients,42 males and 48 females,aged 18-60 years,BMI 18.5-27.9 kg/m^(2),ASA physical statusⅠorⅡ,undergoing elective rigid bronchoscopy were selected.The patients were divided into three groups by random number table:low frequency jet ventilation group was treated with jet ventilation at a rate of 20 beats/minutes(group J20),normal frequency ventilation group was treated with jet ventilation at a rate of 60 beats/minutes(group J60),high frequency ventilation was treated with jet ventilation at a rate of 150 beats/minutes(group J150),30 patients in each groups.Peak inspiratory pressure(PIP),mean inspiratory pressure(MIP),oxygenation index(PaO_(2)/FiO_(2)),and PaCO_(2) under jet ventilation were recorded at 5 minutes after induction of anesthesia(T_(1)),5 minutes after the start of surgery(T_(2)),and the end of surgery(T_(3)).Ventilation ratio in different regions of the lung during jet ventilation(ROI_(1),ROI_(2),ROI_(3),ROI_(4))and impedance value(IR)were obtained and recorded by EIT.Results Compared with group J20,PIP,MIP and PaO_(2)/FiO_(2) were significantly decreased and PaCO_(2) was increased during ventilation in group J60 and group J150(P<0.05),the proportion of ventilation in ROI_(1),ROI_(2),ROI_(3) and ROI_(4) regions was significantly decreased in group J60 and group J150(P<0.05),and IR values were significantly decreased in group J60 and group J150(P<0.05).Compared with group J60,PIP,MIP and PaO_(2)/FiO_(2) were significantly decreased and PaCO_(2)was increased during ventilation in group J150(P<0.05),the proportion of ventilation in ROI_(1),ROI_(2),ROI_(3) and ROI_(4) regions was significantly decreased in group J150(P<0.05),and IR values were significantly decreased in group J150(P<0.05).There were no significant differences in lung ROI_(1),ROI_(2),ROI_(3),and ROI_(4) regions at T_(1)-T_(3).Conclusion The pulmonary gas distribution changes significantly in patients undergoing rigid bronchoscopy at different jet ventilation frequencies,and jet ventilation at 150 beats/minutes can significantly improve the homogeneity of pulmonary gas distribution under the premise of sufficient oxygenation.