Ultrasound Evaluation Of The Incidence Of Atelectasis And Lung Recruitment In Laparoscopic Surgery In Elderly Patients

Objectives:1.To evaluate the incidence and severity of postoperative atelectasis by lung ultrasound in laparoscopic colorectal cancer surgery in elderly patients.2.Evaluate the role of ultrasound-guided recruitment manoeuvre and provide a basis for the application of ultrasound in perioperative period.Methods:Patients more than 60 years old,with physical status classification(ASA)?-?,undergoing laparoscopic colorectal cancer surgery were included in the study.Forty two elderly patients were randomly divided into the control group(n=21)and the recruitment manoeuvre group(n=21)and obtained the same methods of anesthesia and mechanical ventilation.Patients in the two groups were examined by lung ultrasound at three time points:before anesthesia(T1),at the end of surgery(T2)and 30 minutes after extubation(T3).The method of performing ultrasound:each hemithorax was divided into 12 regions by three vertical lines(parasternal,anterior and posterior axillary)and two horizontal lines(parallel to the nipple,diaphragm).Using a abdominal convex array probe of 2-5MHz to scan 12 regions of the lung vertically or parallel to the intercostals and the ultrasonic signs of each region were scored by lung ultrasound:0-normality with the lung "sliding" sign,A-lines and 0 to 2 B-lines.1-thickened,irregular and coarsened pleural line,minimal juxtapleural consolidation or more than three B-lines.2-thickened,irregular and coarsened pleural line,multiple coalescent B-lines or small-sized consolidation.3-white lung or large-sized consolidation.We defined anesthesia-induced atelectasis to be significant if any region had a consolidation score of ?2.At the end of surgery(T2),recruitment manoeuvre was performed guided by lung ultrasound in RM-group.The airway pressure gradually increased from 10 cmH2O by 5 cmH2O increments until the consolidation disappeared on ultrasound and maintained for 40 seconds under the airway pressure and then continued mechanical ventilation.The airway pressure was limited to 40 cmH2O.In the control group,patients were without recruitment manoeuvre and continued mechanical ventilation.After the conditions of extubation were met,endotracheal tubes were removed in each group and then sent patients to PACU for further observation and treatment.PaO2 and SpO2 at T1,lug ultrasound scores at different time points(T1,T2,T3),PaO2,PaCO2and SpO2 at T3,length of surgery,blood loss in operation,postoperative pulmonary symptoms,length of stay of the two groups were recorded.Results:(1)There were no significant differences in gender,age,ASA grade,lung ultrasound score at T1,length of surgery,blood loss in operation,length of PACU time,length of stay,PaO2and SpO2 at T1,PaO2,PaCO2 and SpO2 at T3 and pulmonary symptoms between the two groups(P>0.05).(2)At T2,There was no significant difference in the lung ultrasound scores between the control group and the recruitment manoeuvre group(9.00(6.00?9.00)vs.9.00(6.50?11.00),P>0.05).There was no significant difference in the incidence of atelectasis which was 95%in the control group and 100%in the recruitment manoeuvre group(P>0.05)and the total atelectasis was 97.5%.(3)At T3,the lung ultrasound scores of patients in the recruitment manoeuvre group were lower than those in the control group(3.00(2.00?5.00)vs.9.00(7.00?10.00),P<0.001).The incidence of atelectasis was significantly lower in the recruitment manoeuvre group than in the control group(95%vs.50%,P<0.001).(4)In control group,there was no significant difference in lung ultrasound scores between T2 and T3(9.00(6.00?9.00)vs.9.00(7.00?10.00),P>0.05).In recruitment manoeuvre group,the lung ultrasound scores at T3 were significantly lower than it at T2(3.00(2.00?5.00)vs.9.00(6.50?11.00),P<0.001).(5)Postoperative atelectasis mainly occurred in region 5 and 6 of the back.Conclusions:1.The incidence of atelectasis after laparoscopic colorectal cancer surgery in elderly patients was 97.5%.2.Ultrasound-guided recruitment manoeuver can effectively reduce the incidence of postoperative atelectasis,reduce lung ultrasound scores and improve pulmonary ventilation,and the application of lung ultrasound in perioperative period is worth promoting.