Risk Factors Influencing The Efficacy Of Extracorporeal Membrane Oxygenation In The Treatment Of Acute Respiratory Distress Syndrome In Adults

According to relevant reports[1-6],acute respiratory distress syndrome(ARDS)is now a relatively common clinical disease,accounting for more than 10%of all patients were admitted to ICU.ARDS is an excessive pulmonary inflammatory response that can lead to hypoxemia,hypercapnia,pulmonary hypertension,increased pulmonary dead space and decreased lung compliance.On the basis of the treatment of primary diseases,the treatment regimen of small tidal volume combined with positive end-expiratory pressure(PEEP),muscle relaxants,prone position,inhaling nitric oxide and intravenous steroids has become a clinically mature treatment method.Nevertheless,the mortality rate of ARDS patients is still as high as 46%[4,7],and the mortality rate of patients with extremely severe ARDS is even higher[8].At present,in order to improve the in-hospital survival probability and long-term survival outcome of ARDS patients,the medical community is still exploring new support means for ARDS patients and continuing to improve patient support programsIn 1972,Hill et al.[9]successfully treated a 24-year-old ARDS patient with extracorporeal membrane oxygenation(ECMO),but the curative effect of the other patients treated with ECMO since then were not very ideal due to serious complications Then the treatment of ECMO in neonatal respiratory failure achieved great success[10]The principle of ECMO is to drain the blood out of the body from the venous system through a blood pump,then use a membrane oxygenator to oxygenate the blood and expel the carbon dioxide from it,in the end,the fresh blood is pumped back to the venous or arterial system,thus to partially or completely substitute unction of the heart and/or the lungs,Therefore,there are VV-ECMO and VA ECMO in clinic,and the former is most commonly used in respiratory related patients such as ARDS[11].In recent years,Severe influenza virus outbreaks frequently(CESAR),With in-depth research on the rationale of ECMO and accumulated experience in treating severe diseases,ECMO has more and more obvious advantages in treating ARDS compared with traditional use of ventilator[12],the vv-ecmo can make the damaged lung tissue get a full rest by improving patient's oxygenation and help eliminating CO2,Thus,it has become the first choice for ARDS patients when ventilator therapy don't work very well,which can gain more time for the recovery of lung functionAlthough ECMO has become a commonly used method In the treatment ofARDS,But there is still a great of difference in its clinical effect in different therapeutic centers.Besides,the domestic data on the effect of vv-ecmo on the outcome of patients with severe ARDS are very limited.11 the existing relevant reports are mainly case report,clinical studies with large sample are rarePeople's hospital of zhongshan city is the first hospital to carry out ECMO technology in China except Hong Kong and Taiwan.their annually number of ECMO-treated cases ranks among the top five in China mailand.in recent years,this center has saved a large number of ARDS patients by the usage of ECMO.we plan to collect all their medical records,analyze their survival factors,and discuss the relevent risk factors that may affect the patients' prognosis,so as to provide reference and clinical evidence for the treatment of such patients in the futureObjective:To analyze the relevant risk factors of extracorporeal membrane oxygenation in the treatment of adults with acute respiratory distress syndrome,so as to provide clinical evidence for improving the treatment and management of ECMO in ARDS patientsMethods:1.The basic data of adult ARDS patients treated with vv ECMO in Zhongshan people's hospital from January 2017 to April 2019 were collected.Exclusion criteria ECMO supporting less than 24 hrsOr the patient is pregnant2.patients were divided into two groups:Successful withdrawal of the ECMO group(success group)and unsuccessful withdrawal of the ECMO group(failure group)Successful withdrawal of ECMO was defined as patient survived for more than 24 hrs after the ECMO withdrawal and no need of retreatment3.Observation indicators(1)general information:age,sex,estimated body weight,preoperative complications(hypertension/diabetes)(2)the relevant indicators before ECMO Treatment:APACHE ? score,mechanical ventilation time,tidal volume,Positive end-expiratory pressure ventilation(PEEP)index,the worst oxygenation index,lactic acid,mean arterial pressure(MAP)and left ventricular ejection fraction(ejection fraction,EF)(3)relevant indicators during the ECMO assisting period:lactate level at 24 h with ECMO,flow rate at 24 h with ECMO,arterial oxygen partial pressure at 24 h with ECMO,and ECMO weaning time(4)occurrence of complications:the requirement of continuous renal replacement therapy(CRRT),pulmonary complications,cerebral hemorrhage,ECMO mode alteration4.Statistical analysiscompare and analyze all the observation indexes in the two groups respectively,screening suspicious risk factors that would failed the successful withdrawal of ECMO ROC curve analysis was performed on the above factors to infer their critical value,and then Logistic regression analysis was performed on the same factors to determine the risk factors that would affect the ECMO weaning successfullyResults:1.A total of 52 patients were included in the study,including 32 males and 20 females Age 21?77(48.3±15.1)years old,there were 27 cases(52%)in the success group while 25 cases(48%)in the failure group.4 patients in the success group died before discharge.The overall survival rate was 44%2.group comparison(1)general situation:there was no significant difference in age,gender,estimated body weight,preoperative complications(hypertension/diabetes)(P>0.05)between the two groups(2)relevent conditions before ECMO treatment:mechanical ventilation time,tidal volume,PEEP Index,the worst oxygenation index,lactic acid level,MAP and left ventricular EF Between the two groups are all not showed significant difference(P>0.05)(3)relevant information during the ECMO assisting period:there was no significant difference in flow rate,arterial oxygen partial pressure at 24 h with ECMO and ECMO assisting time between the ywo groups(P>0.05)(4)occurrence of complications:CRRT(12 cases in the success group/24 cases in the failure group,44%vs 96%;P<0.001),pulmonary complications(2 cases in the successful group/8 cases in the failed group,4%vs 32%;P=0.036),cerebral hemorrhage(0 cases in the successful group/4 cases in the failed group,0 vs 16%;P=0.047),ECMO mode alteration(1 case in the successful group/7 cases in the failed group,4%vs 28%;P=0.022)3.other indicators:APACHE ? score before ECMO treatment,lactic acid level at 24 h with ECMO between the two groups are all showed significant differences(P<0.05);ROC curve analysis was performed for APACHE score before ECMO treatment and lactic acid level at 24 h with ECMO respectively,then take their critical value as the cut-off point,convert them into binary variables,at last analysis them with the above variables by Logistic regression analysis4.Logistic regression analysis showed that lactic acid level(>3.10mmol/L)at 24 h with ECMO and CRRT requirement were independent risk factorsConclusion1.During ecmo-treatment of adult ARDS,the lactic acid level(>3.10mmol/L)at 24 h with ECMO and CRRT requirement are two independent risk factors for the failure of ECMO withdrawal2,APACHE ? score(>18.5)before the ECMO treatment,pulmonary complications during ECMO supporting,cerebral hemorrhage,the need to change the mode of ECMO may be lead to Unsuccessful ECMOwithdrawal.