Analyses Of The Associations Between The Anesthesia Management Strategies And Postoperative Outcomes In Infants And Neonates Undergoing Thoracoscopic Surgery

Background Minimally invasive surgery,represented by thoracoscopic surgery,has advantages of less trauma,quick postoperative recovery and less surgical scar,and has been widely used in children’s thoracic surgery,cardiovascular surgery(such as ligation of patent ductus arteriosus)and orthopedic surgery(such as anterior spinal fusion for spine deformity).With the advances of surgery and anesthesia techniques,as well as the improvement of endoscopic equipment and instruments(such as high-definition camera system,3 mm trocar,Hem-o-lok clip,etc.),thoracoscopic surgery has been gradually used in infant and even neonatal thoracic surgery.Due to the unique anatomic,physiological,and pathological characteristics of infants and neonates,management of the infants and neonates undergoing thoracoscopic surgery,presents significant challenges for surgeons,anesthesiologists,and intensive care medicine physicians.The associations between anesthesia management strategies and postoperative outcomes in infants and the newborns undergoing thoracoscopic surgery,still remains unclear.Objective To investigate the incidence,related factors and outcome of post-operative pulmonary complications(PPC)in infants undergoing thoracoscopic surgery with one-lung ventilation,the effects of small tide volume protective lung ventilation strategy on the outcome was especially focused;and to analyze the peri-operative mortality and predict factors in neonates with congenital diaphragmatic hernia(CDH)in the era of minimally invasive surgery.Methods This study consists of two parts.In the first part of the study,we retrospectively reviewed the electrical medical records of all the infants undergoing elective thoracoscopic surgery with one lung ventilation in the Children’s Hospital,Capital Institute of Pediatrics,between January 2016 to December 2020.The post-operative pulmonary complications(PPC),including respiratory failure,pneumonia,atelectasis and pneumothorax,were recognized according to the PPC diagnosis criteria,and the incidence of PPC was analyzed.The subjects were divided into Case group(with PPC)and Control group(with no PPC).Seventeen potentially related factors of PPC were analyzed,including gender,months of age,weight,surgical procedure(sequestration excision,segments excision,lobectomy,diaphragm or mediastinal mass surgery),transfer to open thoracotomy,operation time,intra-operative fluid balance,intra-operative transfusion,small tidal volume lung ventilation(Vt≤7 mL/kg)during the surgery,basic dynamic lung compliance(tidal volume/[PIP-PEEP]),intra-operative(maximum)end-tidal carbon dioxide partial pressure(PetCO2),and oxygenation index(OI,OI=PaO2/FiO2),hemoglobin(Hb)and albumin(Alb)levels in the serum at baseline and post-operatively.Multivariate Logistic regression analysis was used to investigate the independent risk factors of PPC.The needs for postoperative ICU admission,the length of stay in the hospital and the medical expenses,were compared between the two groups.In the second part of the study,all neonates with CDH undergoing surgical repair in our hospital,from January 2016 to December 2019,were reviewed,and the mortality within 30 days after surgery was analyzed.The neonates were divided into Group survival and Group death according to whether they were survived within 30 days after surgery.Univariate analysis was performed to compare the general information,preoperative,intraoperative and postoperative predictors between the 2 groups,to determine the clinical predictors of mortality within 30 days after surgery in the neonates with congenital diaphragmatic hernia.Results In the first part of the study,a total of 295 infants underwent selective thoracoscopic surgery under one-lung ventilation during the study period,and the incidence of PPC was 18.3%(54 cases),with respiratory failure of 11.5%(34 cases),pneumonia of 6.8%(20 cases),pneumothorax of 3.4%(10 cases),and atelectasis of 1.0%(3 cases).Surgical procedure(mediastinal mass surgery vs other procedures),transition to thoracotomy,operation time,blood transfusion,basal dynamic lung compliance,intraoperative maximum PetCO2,and postoperative OI and Alb,were significantly different between the Control and the Case group(P<0.05).Multivariate Logistic regression analysis showed that mediastinal mass surgery(OR=7.4,95%confidence interval[CI]:2.4-22.5),intra-operative maximum PetCO2>50 mmHg(OR=3.4,95%CI:1.2-9.6)and postoperative OI<290 mmHg(OR=4.6,95%CI:1.6-12.9),were 3 independent risk factors of PPC.Compared with the control group,more children in the Case group were transferred to ICU post-operatively(33.3%vs 1.2%,P<0.05),the length of stay in the hospital was prolonged(8[6-12]days vs 6[5-7]days,P<0.05),and the medical expenses was increased(43[36-64]vs 36[33-39],thousand RMB yuan,P<0.05).All the infants were recovered and discharged post-operatively.In the second part of the study;a total of 50 cases of neonates with CDH undergoing surgical repair in our hospital from January 2016 to December 2019,of which 32(64%)were completed with thoracoscopy.Fifteen neonates died within 30 days after surgery,and the overall mortality rate was 30%.Univariate analysis showed that,prenatal diagnosis before 25 weeks gestational age(P=0.006),low birth weight(<2500 g,P=0.029),combined with simple congenital heart disease(P=0.037),preoperative use of high-frequency oscillatory ventilation(HFOV,P<0.001),preoperative oxygenation index(OI=100 ×mean airway pressure × FiO2/PaO2,FiO2:fraction of inhaled oxygen,PaO2:arterial partial pressure of oxygen;P=0.007),American Society of Anesthesiologists(ASA)physical status(P=0.014),age at surgery after birth(P=0.045),open laparotomy(P<0.001)and postoperative OI(P<0.001),were 9 predict factors of mortality.Conclusion The incidence of post-operative pulmonary complications in infants undergoing thoracoscopic surgery with single lung ventilation is high.Mediastinal mass surgery,intra-operative maximum PetCO2 over 50 mmHg,and post-operative oxygenation index less than 290 mmHg,are 3 independent risk factors of post-operative pulmonary complications.The needs for ICU admission post-operatively,the length of stay in the hospital and the medical expenses,are significantly increased in the infants with post-operative pulmonary complications.No protective effect of small tidal volume ventilation or permissive hypercapnia in infants undergoing thoracoscopic surgery with one lung ventilation was observed.In an era of minimally invasive surgery,neonates with congenital diaphragmatic hernia had a mortality rate of 30%within 30 days after surgery,mainly related to the severity of the disease;prenatal diagnosis gestational age,low birth weight(<2500 g),combined with simple congenital heart disease,preoperative needs of high-frequency oscillatory ventilation,preoperative oxygenation index,ASA physical status,age at surgery after birth(hours),surgical techniques(thoracoscopic vs.open surgery),and postoperative oxygenation index,have predictive values for postoperative outcomes.