Weaning And Outcome Of Mechanically Ventilated Patients Predicted By Diaphragm Function

Objective:To evaluate the predictive value of diaphragm and micro RNA in plasma in the outcome of weaning of mechanically ventilated patients.Methods:A prospective observational research was conducted.Patients were admitted to the Department of Critical Care Medicine,Zhongda Hospital,Southeast University from May 2018 to February 2019,and who received invasive mechanical ventilation for more than 12 hours and met the inclusion criteria were enrolled.After the patient was enrolled,the diaphragmatic catheter was placed and the position was confirmed.In the 5cmH₂O CAPA mode,the patient's neuro-ventilatory efficiency?NVE?and neuro-mechanical efficiency?NME?were measured according to the diaphragmatic electrical signal.The excursion of diaphragm?EXdi?and thickening fraction of diaphragm?TFdi?on the right side were both measured by the ultrasound.Each enrolled patient would be screened at 8 a.m.daily to see whether the conditions for pre-weaning are met.A 30-minute 5cmH₂O CPAP spontaneous breathing test was performed on eligible patients.The patients who passed the trial were subjected to weaning and extubation,and the prognosis was followed up.Patients who did not pass the trial would be assessed again on the next day.Peripheral blood samples were collected on the first day of mechanical ventilation.The expression level of miRNAs in plasma were detected by RT-PCR.The following data were recorded on the first day of mechanical ventilation:?1?The characteristics as age,gender,acute physiology and chronic health status score II?APACHE II?,the main cause of mechanical ventilation.?2?Ventilator mode and parameters,respiratory form,respiratory mechanics,gas exchange.?3?Hemodynamics and the use and dose of vasoactive drugs?4?Inflammatory indicators:WBC,CRP,PCT,IL-6?5?The function of diaphragm?NVE,NME,EXdi,TFdi??6?The expression level of miRNAs in plasma.According to the WIND study,the prognosis of patients was divided into three groups,including simple weaning,difficult weaning,and prolonged weaning.The study defined the difficult weaning and prolonged weaning as non-simple weaning.According to the results of previous studies,patient who met at least one of these criterias?EXdi<1 cm,and TFdi<30%?was defined as diaphragmatic dysfunction.The above recording data will be analysised in comparison in three groups.The factors of weaning were included in the binary logistic regression analysis.The risk ratio models of non-simple weaning and prolonged weaning were established.Finally,the predictive value of factors in the outcome of weaning of mechanically ventilated patients were compared.Results:1 Baseline Characteristics57 patients were enrolled,including 20 patients with simple weaning,20 patients with difficult weaning,and 17 patients with prolonged weaning.Patients with prolonged weaning were older than patients with simple and difficult weaning.The APACHE II score of patients with difficult and prolonged weaning was significantly higher than those with simple weaning.2 Comparison of respiratory form and respiratory mechanics?1?There was no significant difference between the tidal volume?VT?,the respiratory rate and the rapid shallow breathing index?RSBI?in patients with simple weaning and difficult weaning.VT of patients with prolonged weaning was significantly lower than that of simple and difficult weaning patients,and the respiratory rate and RSBI were significantly higher than that of simple and difficult weaning patients.?2?There was no significant difference in driving pressure and airway resistance between these three groups.The respiratory compliance of patients with prolonged weaning was significantly lower than that of patients with simple and difficult weaning.?3?There was no significant difference in pH,PaCO₂,lac,HCO3-,and hemoglobin concentration in these three groups,and the oxygenation index?PaO₂/FiO₂,P/F?of patients with prolonged weaning was significantly lower than that of patients with simple and difficult weaning.3 Comparison of the function of diaphragm:EXdi of patients with prolonged weaning was significantly lower than that of patients with difficult weaning.There were no significant differences in TFdi between the three groups.NVE in patients with difficult and prolonged weaning was significantly lower than that in patients with simple weaning[43.09?29.87-58.49?vs.45.69?27.94-74.63?vs.82.2?59.75-97.10?,?P<0.05?.NME in patients with difficult and prolonged weaning was significantly lower than that in patients with simple weaning[1.06?0.74-1.57?vs.1.09?0.68-1.61?vs.1.91?1.50-2.79?,?P<0.05?].The proportion of diaphragm dysfunction were 64.91%.4 Comparison of expression level of miRNA in plasmaThe expression level of miRNA-1 and miRNA-206 in plasma of patients with difficult and prolonged weaning was significantly lower than that of patients with simple weaning.The expression level of miRNA-1 of patients with prolonged weaning was higher than that of patients with difficult weaning.5 Correlation between the level of miRNA in plasma and the function of diaphragmThere was no correlation between miRNA-1 levels and EXdi,TFdi,NVE,NME.The level of miRNA-206 were positively correlated with NVE and NME,with correlation coefficients of 0.316 and 0.378 respectively.6 Comparison of the predictive value of diaphragmatic function on the prognosis of weaningThe ROC area of NVE<73.660 ml/?v predicting non-simple weaning ROC area of0.840,sensitivity is 0.838 and specificity is 0.700.The ROC area of NME<1.229cmH20/?v predicting non-simple weaning is 0.840,sensitivity is 0.622 and specificity is 0.950.The ROC area of miRNA-1 predicting non-simple weaning is 0.929.The ROC area of miRNA-206 predicting non-simple weaning is 0.861.7 Multi-factor regression analysis of the prognosis of mechanical ventilation?1?Compared to simple weaning,respiratory system compliance,the level of miRNA-1 and miRNA-206 in plasma are the independent protective factors of non-simple weaning.OR values were 0.901?0.817-0.994?,0.980?0.963-0.997?,and 0.988?0.977-0.998?respectively.?2?Compared to simple and difficult weaning patients,age is an independent risk factor for prolonged weaning,and respiratory compliance is an independent protective factor for prolonged weaning.The OR values were 1.058?1.005-1.115?and 0.939?0.886-0.996?respectively.8 Correlation analysis between mechanical ventilation time and expression level of miRNA in plasmaMechanical ventilation time was positively correlated with miRNA-206 ratio on first day and the weaning day of mechanical ventilation,with a correlation coefficient of0.571,and miRNA-1 is not relevant.Conclusion:Patients receiving mechanical ventilation have a high incidence of diaphragm dysfunction on the first day of mechanical ventilation.NVE,NME and the expression levels of miRNA-1 and miRNA-206 in plasma on the first day of mechanical ventilation have predictive value for outcome of weaning.Objective: Investigate the relationship between the changes of mi RNA in plasma and the change of diaphragm thickness during mechanical ventilation,and to observe the effect of diaphragm thickness on the outcome of patients.Methods:A prospective observational research was conducted.Patients were admitted to the Department of Critical Care Medicine,Zhongda Hospital,Southeast University from May 2018 to February 2019,and who received invasive mechanical ventilation for more than 12 hours and difficult or prolonged weaning patients.After the patient was enrolled,the diaphragmatic catheter was placed and the position was confirmed.In the 5cm H2 O CAPA mode,the patient's neuro-ventilatory efficiency?NVE?and neuro-mechanical efficiency?NME?were measured according to the diaphragmatic electrical signal.The peripheral blood samples were collected on the first day and weaning of mechanical ventilation.The thickness of the diaphragm?Tdi?,excursion of diaphragm?EXdi?and thickening fraction of diaphragm?TFdi?were also measured by the ultrasound on the first,third,and seventh days of mechanical ventilation in 5cm H2 O CPAP mode.The following data were recorded:?1?The characteristics as age,gender,acute physiology and chronic health status score II?APACHE II?,the main cause of mechanical ventilation.?2?Ventilator mode and parameters,respiratory form,respiratory mechanics,gas exchange.?3?NVE,NME on first day of mechanical ventilation,and Tdi,EXdi,TFdi on the first,third,and seventh days of mechanical ventilation?4?The expression level of mi RNAs in plasma on the first and weaning day of mechanical ventilation?5?28-day,ICU and hospital mortality,mechanical ventilation time,length of ICU stay,etc.Patients were divided into survival group and non-survival group according to the patient's 28-day survival.The general characteristics,respiratory form and respiratory mechanics,and the changes of diaphragm function and mi RNA level were compared between the two groups.And the relationship between ?Tdi% and NVE,NME,EXdi and TFdi was analyzed.The area under the ROC curve was used to estimate the predictive value of the diaphragma function on the 28-day mortality.Kaplan-Meier survival curves were used to analyze the effects of different diaphragm function on 28-day survival.Results :1 Baseline CharacteristicsIn this study,37 patients with difficult weaning and prolonged weaning were enrolled,28 patients survived and 9 patients died.The overall age of the patients was 60.43±18.21 years old,and the APACHE II score was 18.95±5.86.There were no significant differences in age,gender,BMI,and underlying diseases among the two groups?P>0.05?.2 Comparison of respiratory form and respiratory mechanicsThere was no significant difference in respiratory form and respiratory mechanics between the survival group and non-survival group?P>0.05?.The oxygenation index of patients in the non-survival group was significantly lower than that in the survival group [207.20?189.80-227.60?vs.273.75?218.70-350.05?,P<0.05].The hemoglobin concentration in the non-survival group was lower than that in the survival group.There were no significant differences in arterial blood gas p H,carbon dioxide partial pressure,lactic acid and bicarbonate concentrations between the two groups?P>0.05?.3 Comparison of diaphragm functionThere was no significant difference in the Tdi and TFdi values between the two groups on the 1st,3rd and 7th day of mechanical ventilation?P>0.05?.EXdi of the non-survivors was lower than the survivals.?Tdi% of non-survivals was significantly lower than that of the survivals [-27.66?-38.00--10.34?vs.4.67?-14.41-21.11?,P<0.05].4 Correlation analysis between ?Tdi% and NVE,NME,EXdi and TFdiThe absolute value of ?Tdi% is negatively correlated with TFdi,and the correlation coefficient is-0.504.5 Comparison of the expression level of mi RNA-1 and mi RNA-206 in plasmaThere was no significant difference between in these two groups on the expression levels and the change of mi RNA-1 and mi RNA-206 on the first day and weaning day of mechanical ventilation in plasma?P>0.05?.6 Comparison of prognosisThere was no significant difference between the non-survival group and the survival group?the proportion of difficult and the prolonged weaning??P>0.05?.The time of mechanical ventilation free day and total hospital stay in the non-survival group were significantly lower than those in the surviving group within 14,28,and 60 days.7 ? Tdi% and EXdi predictive value of patients' survival:?Tdi% predicts the survival area of patients with an area under the ROC curve of 0.7893?0.6949-0.9837?,?Tdi%<-22% predicts death and sensitivity is 0.6667,specificity is 0.8966.The area under the ROC curve for predicting patient survival by EXdi was 0.7282?0.5584-0.8979?,and the sensitivity for predicting 28-day mortality for EXdi<1.52 cm was 1 and the specificity was 0.4286.There was a significant difference in 28-day survival between patients with ?Tdi%<-22% and ?Tdi%?-22%.There was no significant difference in 28-day survival between patients with EXdi < 1.52 cm and EXdi ? 1.52 cm?P = 0.077?.Conclusion:Changes in diaphragm thickness and excursion of diaphragm have predictive value for patient prognosis.Patients with a decrease in diaphragm thickness greater than 22% had a significantly lower 28-day survival.