Association Between Changes Of Local Tissue Oxygen Saturation And Postoperative Complications In Thoracotomy With One-Lung Ventilation

Part one Association Between Changes of Cerebral Oxygen Saturation and Postoperative Delirium in Thoracotomy With One-Lung VentilationObjective:The association between changes of cerebral oxygen saturatio and postoperative delirium in thoracotomy with one-lung ventilation（OLV）has not been specifically studied.Methods:This study is a prospective observational cohort study.This study was conducted in the First Hospital of Peking University and the Fourth Hospital of Hebei Medical University from September 2017 to October 2018.The subjects were patients who underwent elective thoracic surgery and needed one-lung ventilation.The inclusion criteria:1)Age≥55years;2)The expected operation time≥2 hours.The exclusion criteria were any of the following:1)refusal to participate;2)emergent surgery;3)poor hearing or vision,language barrier impeding delirium assessment;4)history of schizophrenia;5)Serious cognitive impairment,such as coma and dementia;6)American Society of Anesthesiologists physical status>Ⅲ;7)Researchers believe that they are not suitable to participate in the study.Anesthesia induction was accomplished using a bolus of propofol（2–4 mg/kg）and continuous infusion of sufentanil（site-effect concentration,0.2–0.5 ng/mL）.Anesthesia was maintained using propofol（4–10 mg/kg/h）and sufentanil（site-effect concentration,0.2–0.5 ng/mL）continuous infusion.Bispectral index（BIS）monitor was used to maintain the BIS value between 40 and 60.Adjust the respiratory parameters to maintain the end-expiratory carbon dioxide partial pressure(P_ETCO₂)between 35-45mm Hg.The goal of hemodynamic maintenance is to keep the change of systolic blood pressure within 20%of the baseline value and maintain the peripheral SpO₂ above 92%.The patient controlled intravenous analgesia（PCIA）technique was used to maintain the postoperative digital pain（NRS）score≤3 points.Tissue oxygen saturation was monitored using the FORE-SIGHT ELITE tissue oximeter.We monitored 4 tissue beds,including the left forehead,right forehead,forearm over the brachioradialis muscle,and upper thigh over the quadriceps.Data collection:preoperative data of patients,including basic information,past medical history and cognitive function evaluation;Intraoperative data,including the basic value of tissue oxygen saturation and intraoperative monitoring data of tissue oxygen saturation,anesthesia related information,surgery related information,mechanical ventilation related information,intraoperative adverse events,intraoperative fluid intake,blood loss and urine volume;Postoperative follow-up data,including delirium assessment,pain assessment,postoperative complications and postoperative hospital stay,etc.The confounding factors,such as age,OLV time,use of midazolam,occurrence of hypotension and severity of pain,were controlled.Multivariate logistic regression was used to analyze the relationship between the lowest SctO₂ and POD,the decrease of tissue oxygen saturation,the increase of tissue oxygen saturation and POD,and the relationship between AUT/AAT and POD.Results:A total of 175 patients（65±6 years old）were included in this study,including 105 patients from the Fourth Hospital of Hebei Medical University and 70 patients from the First Hospital of Peking University.Delirium occurred in 35（20%）of 175 patients.After controlling for confounding factors such as age,OLV time,use of midazolam,occurrence of hypotension and severity of pain on the first day after operation,multivariate logistic regression analysis showed that:1)The lowest value of left or right SctO₂ was not correlated with the occurrence of POD;2)The left SctO₂<90%baseline and the right SctO₂<85%baseline are related to the increased risk of POD,while the other（lower/higher）SctO₂ and SmtO₂ based on the relative threshold change are not related to the increased risk of POD;3)SctO₂ and SmtO₂ based on absolute value changes（decrease/increase）have no correlation with the increased risk of POD;4)The AUT/AAT calculated based on the relative change threshold or absolute value threshold has no correlation with the occurrence of POD.Conclusions:The incidence of POD in patients undering thoracotomy with OLV was 20%;The minimum SctO₂ was not related to the occurrence of POD in patients undergoing thoracotomy;The left SctO₂<90%of baseline or the right SctO₂<85%of baseline,lasting for 15 seconds or more,is related to the increase of POD risk in patients undergoing thoracotomy.Part two Muscular tissue desaturation and pneumonia in patients in Thoracotomy With One-Lung VentilationObjective: To investigate the association between muscular tissue desaturation and postoperative pneumonia in patients receiving lung cancer surgery.Methods: This study is a retrospective analysis of the previous prospective cohort study.This study was conducted in the First Hospital of Peking University and the Fourth Hospital of hebei Medical University from September 2017 to October 2018.The inclusion criteria: 1)Age ≥ 55 years;2)undergoing lobectomy with one-lung ventilation;3)The expected operation time≥ 2 hours.The exclusion criteria were any of the following: 1)refusal to participate;2)emergent surgery;3)poor hearing or vision,language barrier impeding delirium assessment;4)history of schizophrenia;5)Serious cognitive impairment,such as coma and dementia;6)American Society of Anesthesiologists physical status >III;7)Researchers believe that they are not suitable to participate in the study;8)The intraoperative SmtO₂ data were incomplete.Anesthesia induction was accomplished using a bolus of propofol（2–4 mg/kg）and continuous infusion of sufentanil（site-effect concentration,0.2–0.5 ng/mL）.Anesthesia was maintained using propofol（4–10 mg/kg/h）and sufentanil（site-effect concentration,0.2–0.5 ng/mL）continuous infusion.Bispectral index（BIS）monitor was used to maintain the BIS value between 40 and 60.Adjust the respiratory parameters to maintain the end-expiratory carbon dioxide partial pressure(P_ETCO₂)between 35-45 mm Hg.The goal of hemodynamic maintenance is to keep the change of systolic blood pressure within 20% of the baseline value and maintain the peripheral SpO₂ above 92%.The patient controlled intravenous analgesia（PCIA）technique was used to maintain the postoperative digital pain（NRS）score ≤ 3 points.Tissue oxygen saturation was monitored using the FORE-SIGHT ELITE tissue oximeter.We monitored 2 tissue beds,including the forearm over the brachioradialis muscle and upper thigh over the quadriceps.Data collection: preoperative data of patients,including basic information,past medical history and cognitive function evaluation;Intraoperative data,including the basic value of tissue oxygen saturation and intraoperative monitoring data of tissue oxygen saturation,anesthesia related information,surgery related information,mechanical ventilation related information,intraoperative adverse events,intraoperative fluid intake,blood loss and urine volume;Postoperative follow-up data,including POP,pain assessment,postoperative complications and postoperative hospital stay,etc.Single factor logistic regression was used to analyze the relationship between SmtO₂ decrease,SmtO₂ increase,AUT/AAT and POP.The patients were divided into SmtO₂ reduction group（group D）and control group（group C）according to whether SmtO₂ reduced or not.The confounding factors,such as the use of peripheral nerve block,use of propofol,use of sufentanil,age,ASA grade were controlled.Multivariate logistic regression was used to analyze the relationship between between SmtO₂ reduction and POP.Results: A total of 207 patients were screened in this study,and 174 patients were included in the study,including 104 patients from the Fourth Hospital of Hebei Medical University and 70 patients from the First Hospital of Peking University.POP occurred in 35（19.5%）of 174 patients.Patients were divided into SmtO₂ reduction group（n=82）and control group（n=92）according to whether SmtO₂ <80% baseline at forearm or not.The incidence of SmtO₂ reduction was 47.1%.There was no significant difference in age,body mass index,ASA grade,concomitant diseases（stroke,coronary heart disease,hypertension,COPD,asthma,diabetes and hyperlipidemia）,preoperative SpO₂,preoperative PaO₂,FEV1,forearm and lower limb basic SmtO₂,ARISCAT score,operation site,operation mode,application of peripheral nerve block,intraoperative medication（propofol,sufentanil,etomidate,midazolam and inhalation anesthetics）,intraoperative adverse events（hypoxemia,hypotension,minimum PaO₂,maximum PaO₂）,maximum SmtO₂ in forearm and lower limb,average SmtO₂ in lower limb,blood loss,urine volume,crystalloid input,one-lung ventilation time,operation time,anesthesia time,pain score in the first three days after operation and postoperative hospital stay（P>0.05）;There were significant differences between the two groups in gender,smoking history,the lowest SmtO₂ in forearm and lower limb,the average SmtO₂ in forearm,and the incidence of pneumonia（P<0.05）.In order to study the relationship between the change of tissue oxygen saturation（increase and decrease）and POP,this study was divided into pneumonia group（n=34）and non-pneumonia group（n=140）according to whether POP occurred or not.The incidence of POP was 19.5%（34/174）.Multivariable analysis showed that muscular desaturation was associated with an increased risk of pneumonia（OR 2.672,95% CI 1.187-6.017,P=0.021）after adjusted for the use of peripheral nerve block,use of propofol,use of sufentanil,age,ASA grade.Conclusions: The incidence of POP in lung cancer patients after lung surgery was 19.5%;Muscular tissue desaturation,defined by SmtO₂ <80% baseline at forearm,may be associated with an increased risk of postoperative pneumonia.