Analysis Of Influential Factors Of Gas-related Complications In POEM For Achalasia Of Cardia And The Prediction For The Value Of Intraoperative Airway Peak Pressure Monitoring

Objective:1.To analyze the influencing factors of gas-related complications during peroral endoscopic myotomy?POEM?,and to identify the risk factors that may lead to gas related complications,so as to provide reference for how to prevent the occurrence of this complication.2.To evaluate the applicability and accuracy of monitoring the changes of peak airway pressure?Ppeak?during POEM in predicting the occurrence of gas-related complications,and to explore the early diagnostic methods and significance of gas-related complications during POEM.Methods:Part one:The clinical data of 115 patients with AC who underwent POEM in the Sichuan Mianyang 404 Hospital and the General Hospital of Western War Zone from January 2014 to July 2019 were retrospectively analyzed.Collected the general data of patients:age,gender,course of disease,history of previous treatment;preoperative evaluation data:severity of clinical symptoms,shape of esophagus;endoscopic surgery data:tunnel entrance establishment method,tunnel establishment length,myotomy depth,whether to use Hybrid Knife,operation time.According to the occurrence of gas-related complications,the patients were divided into those with gas-related complications and those without gas-related complications,the statistical differences in the relevant indicators between the two were analyzed,the factors affecting the occurrence of gas-related complications were explored,the independent risk factors were selected,and the accuracy of independent risk factors was analyzed with ROC curve.Part two:The clinical data of 38 AC patients receiving POEM treatment in Sichuan Mianyang 404 Hospital from July2017 to July 2019 were observed and analyzed.We divided into groups according to the presence or absence of gas-related complications and their severity.Group A:no gas-related complications,Group B:mild gas-related complications?mediastinal emphysema or/and Subcutaneous emphysema?,Group C:moderate?mediastinal and subcutaneous emphysema combined with pneumoperitoneum?,Group D:severe?combined with pneumothorax?.Closely monitor the changes of Ppeak during operation,and the Ppeak was recorded at 1min after successful anesthesia intubation?T₁?,10 min after the tunnel was dissected?T₂?,tunnel dissection was completed?T₃?,10 min after myotomy?T₄?and myotomy was completed?T₅?for each patient.Meanwhile,the rise of Ppeak within 1min was more than thirty percent,which was set as a significant increase.Firstly,the influencing factors of gas-related complications were analyzed.The Ppeak at different time points during the operation of each group of patients was compared.At the same time,the sensitivity,specificity,positive and negative predictive value for predicting gas-related complications caused by significant increase of Ppeak were calculated.Results:1.Analysis of influencing factors of gas-related complications:Of the 111 patients included,51?45.9%?had gas-related complications?with concurrent conditions?,including subcutaneous emphysema in 32?28.8%?,pneumomediastinum in 21?18.9%?,pneumoperitoneum in 16?14.4%?,and pneumothorax in 9?8.1%?.?1?Univariate analysis showed that duration of disease,previous treatment history,Eckardt score,S-shaped esophagus,tunnel inlet establishment method,total operation time,and use of pebble knife were associated with gas-related complications in AC patients treated with POEM?P<0.05?.?2?Multivariate logistic regression analysis results suggested that previous treatment history?OR,0.057;95%CI,0.014 to 0.233;P<0.001?,S-shaped esophagus?OR,0.12;95%CI,0.016 to 0.918;P=0.041?and total operation time?OR,0.969;95%CI,0.941 to 0.997;P=0.031?were associated with the occurrence of gas-related complications.The presence of previous treatment history,severe esophageal distortion in S-shape,and long total operation time were independent risk factors for gas-related complications during surgery.?3?ROC curve analysis of the AUC of operation time for predicting the occurrence of gas-related complications=0.755?P<0.001?,and the optimal cutoff value calculated using the Youden index method was 82.5 min,at the same time the sensitivity for predicting the occurrence of gas-related complications was 52.9%and the specificity was 91.7%.2.The relationship between Ppeak and gas-related complications:Among the 38 surgical patients observed and analyzed,28?73.68%?had gas-related complications,including 15?39.47%?with mild,8?21.05%?with moderate and 5?13.16%?with severe.?1?Comparison of Ppeak at different time points in each group:In the four groups of patients,Ppeak appeared an upward trend in T₁^T₃ and T₄^T₅ and a downward trend in T₃^T₄.Moreover,the increase degrees of Ppeak of group C and group D in T₂^T₃period were significantly higher than that of group A and group B;There was no significant difference in Ppeak between the four groups at T1 and T2.Ppeaks of Group C and group D were significantly higher than group A and group B at T₃,T₄ and T₅?P<0.05?.There was no significant difference in Ppeak between group A and group B,group C and group D in T3 and T4.Group B was higher than group A and group D was higher than group C at T₅,and the difference was statistically significant?P<0.05?.?2?The accuracy of predicting gas-related complications when Ppeak increases significantly:During the operation,the sensitivity was?78.57%,22/28?,specificity was?80.00%,8/10?,positive predictive value was?91.67%,22/24?and negative predictive value was?57.14%,8/14?for predicting gas-related relative complications caused by significant increase of Ppeak.Conclusion:1.Gas-related complications,including subcutaneous emp-hysema,pneumomediastinum,pneumoperitoneum,and pneumothorax are the most common complications during POEM procedures.Patients with mild symptoms may not require treatment,and those with severe symptoms require emergency treatment,such as closed thoracic drainage and paracentesis for deflation,or even termination of surgery.2.The presence of a history of previous treatment,severe distortion of the esophagus in an S-shaped shape,and prolonged operation time were independent risk factors.Preoperative evaluation of patients with a history of previous treatment and severe esophageal distortion is necessary.Detailed preoperative discussion,the development of a safe and effective protocol which can shorten the operation time and effective preventive measures are required to reduce the incidence of gas-related complications.3.POEM intraoperative Ppeak monitoring has a high clinical value in predicting gas-related complications,and the surgical risk can be reduced by early prevention and intervention.During the operation,it is important to pay close attention to the changes of Ppeak,especially for the patients with risk factors.When Ppeak changes significantly,it is necessary to timely press the subcutaneous loose tissues such as neck and face of the patient,observe the abdominal shape of the patient,actively perform pulmonary auscultation and prevent the occurrence of subcutaneous emphysema,pneumoperitoneum and pneumothorax.