Lung Ultrasound And Perioperative Atelectasis After General Anesthesia

Objectives: The aim of this study was to compare the changes on the lungs at different time points and different areas by observing the changes on the lung ultrasound images of general anesthesia patients who had surgery within two days.On the basis of the study,to research further study of reducing the pulmonary complications after general anesthesia.Methods:72 patients scheduled for surgery were recruited.Mechanical ventilation during operation.Lung ultrasonography was performed at 4 predefined time points:1 day before surgery(T1),30 minutes after extubation(T2),24 hours after operation(T3),48 hours after operation(T4).Parts of LUS investigations: Left Upper Anterior,Left Lower Anterior,Left Upper Lateral,Left Basal Lateral,Left PLAPS Area,Left Lower Posterior,Right Upper Anterior,Right Lower Anterior,Right Upper Lateral,Right Basal Lateral,Right PLAPS Area,Right Lower Posterior.LUS scores:0=normal pattern of healthy lungs with sliding pleura and horizontal A-lines parallel to the smooth pleural line;1=thickened,irregular and coarsened pleural line with or without hypo-echoic juxtapleural consolidations combined with intermittent and scattered B-lines,which were linear vertical artifacts named comet-tail signs;2=thickened,irregular and coarsened pleural line with small,hypo-echoic,juxtapleural consolidation patches combined with diffused B-lines;3=coalescent B-lines arising from irregular pleural lines erasing any A-line;and 4=sizes of subpleural echo-poor regions of tissue-like echo texture with deep margins originating from the pleural line.According to the rules,dealing with different LUS scores at different time points and chest areas differently.Results:(1)Mean LUS scores at baseline(time point T1)were 0.42± 1.09(range0–6),(n = 72).30 minutes after extubation(time pointT2)caused a significant increase in LUS scores,This increase persisted throughout the study period.(p<0.05).(2)The study of the average LUS scores of the left and right chest at time point T2,T3,T4(except time point T4 of left Lower Anterior)compared with time point T1 shows statistical significance(p<0.05).The most significant increase of average LUS scores is on Basal Lateral,PLAPS Area and Lower Posterior.(3)At time point T2,T3,T4,the study of the average LUS scores of the left and right Basal Lateral,PLAPS Area and Lower Posterior compared with Upper Anterior shows statistical significance(p<0.05).(4)The study of the difference of average LUS scores on all the areas of left and right chest at four time points shows no statistical significance.Conclusions: The study shows that lung aeration changed partly on the lung ultrasound image of general anesthesia patients,which indicate possibly atelectasis,especially on Lower Posterior,PLAPS Area and Basal Lateral.The severe symptom appears right after the surgery and may last for one day,and after that shows a tendency to reduce.