Clinical Rearch Of Mechanical Ventilation In Patients With Moderate To Severe Actue Respiratory Distress Syndrone By Lung Ultrasoud

Part 1 Effects of Cardiopulmonary Function and Prognosis with Lung Ultrasound-guided Lung Protection Strategy in Patients with Moderate to Severe Acute Respiratory DistressObjective:To explore the impact on cardiopulmonary function,respiratory mechanics,complications and prognosis of patients with moderate to severe acute respiratory distress syndrome by applying ultrasound scoring method with the expectation of providing clinical guidance for reasonable mechanical ventilation strategies.Methods:This study included 120 patients with moderate to severe ARDS meeting the standards（Berlin-defined）who were admitted to the second ward of the Intensive Medicine Department of the Affiliated Hospital of Guilin Medical College between September 2019 and November 2020.According to the random number table method,120 patients with moderate to severe ARDS were randomly divided into lung ultrasound scoring group（LUS）and maximum pressure control group（PCV）,with 60 cases in each group.The lung protection strategy of the LUS group used the lung ultrasound score-guided PEEP incremental method for lung recruitment.After lung recruitment,the lung ultrasound PEEP decrease method was used to determine the best PEEP;the PCV group lung protection strategy used the pressure control mode of high pressure 40 cm H₂O,PEEP 20cm H₂O.After lung recruitment,the PCV group selected the corresponding best PEEP value according to the ARDS net low PEEP high inspired oxygen concentration table.Collect 15 min（T0）before lung recruitment,15 min（T1）,1h（T2）,2 h（T3）,24 h（T4）,48 h（T5）after lung recruitment,clinical indicators,hemodynamic related indicators:including heart rate,mean arterial pressure,central venous pressure;arterial blood gas analysis related indicators:including p H,Pa CO₂,oxygenation index,lactic acid concentration;cardiac function evaluation indicators:including left ventricular ejection fraction（LVEF）,right ventricular end diastolic area/left ventricular end diastolic area（RV∕LV）,tricuspid valve early diastolic peak E wave/tricuspid valve late diastolic peak A（E/A）,tricuspid valve early diastolic peak E wave/tricuspid late diastolic e-wave peak（E/e）,tricuspid annulus systolic displacement rate（TAPSE）and inferior vena cava diameter（IVC）;respiratory mechanics parameters:including positive end expiratory pressure（PEEP）,peak airway pressure（Ppeak）,airway platform pressure（Pplat）,lung static compliance（Cstat）,airway resistance（Raw）;lung recruitment complications,hospital stay,ventilator use time,mortality and other clinical prognostic indicators,interleukin-6（IL-6）,tumor necrosis factor-α（TNF-α）and high-sensitivity c-response protein（hs-CRP）.Results:A total of 97 patients completed the experiment and were included in the statistical analysis.There were 49 patients in the LUS group and 48 patients in the PCV group.（1）There was no statistical difference in general data between the two groups of patients before lung protection strategy（P>0.05）.（2）Comparison of CVP between the two groups of patients:CVP in the LUS group was significantly higher than that in the PCV group at T1,T2,T3,T4,and T5（P<0.05）.（3）Pa CO₂ comparison of the two groups of patients:Pa CO₂ of the LUS group was higher than that of the PCV group at T1,T2,T3,T4,and T5（P<0.05）.（4）The comparison of OI of the two groups:the OI of the LUS group at the time points of T1,T2,T3,T4,and T5 were higher than those in the PCV group（P<0.05）.（5）Comparison of LVEF,RV/LV,E/A,E/e,TAPSE,IVC between the two groups of patients at T0,T1,T2,T3,T4,T5:there was no statistical difference between the groups（P>0.05）.（6）Comparison of PEEP of two groups patients:PEEP of LUS group was higher than that of PCV group at T1,T2,T3,T4,and T5（P<0.05）.（7）Ctat comparison of two groups of patients:Ctat of LUS group at T1,T2,T3,T4,and T5 were significantly higher than those of the PCV group,which was statistically different（P<0.05）.（8）The length of ICU hospitalization and ventilator use time of patients in the LUS group was lower than that of the PCV group,which was statistically different（P<0.05）.The lung recruitment complications and fatality rates of the LUS group and the PCV group were both with no statistical difference（P>0.05）.（9）The incidence of pleural effusion in the LUS group was significantly lower than that in the PCV group（P<0.05）.（10）There was no statistical difference in the levels of IL-6,TNF-α,hs-CRP inflammatory factors between the two groups of patients at the T0 time point（P>0.05）.At the T5 time point,the level of inflammatory factors in the LUS and PCV group was significantly higher than that before treatment（P<0.05）,and the level in the LUS group increased more significantly.There was a statistical difference between the two groups（P<0.05）.Conclusion:（1）Lung ultrasound score-guided lung protection ventilation strategy can improve the oxygenation of patients with moderate to severe acute respiratory distress syndrome,promote the efficiency of lung ventilation,and the heart function is less affected.（2）Lung ultrasound score-guided lung protection ventilation strategy can shorten the time of using ventilator and ICU hospitalization;meanwhile,the incidence of organ dysfunction is lower,Part 2 Predictive Value of Lung Ultrasound Combined with Echocardiography in the Outcome of Mechanical Ventilation and Weaning in Patients with Moderate to Severe Acute Respiratory Distress SyndromeObjective: To predict the success rate of the weaning process of mechanical ventilation for moderate to severe patients by using lung ultrasound combined with echocardiography.Methods: A case-control study method was used to analyze 97 patients with moderate to severe acute respiratory distress syndrome who were admitted to the second ward of the Intensive Medicine Department of the Affiliated Hospital of Guilin Medical College from September 2019 to November 2020.Collect all the basic clinical information,recorded weaning indices at spontaneous breathing test 15 min before SBT（T0）,30 min after SBT（T1）,12 h after weaning（T2）and 24 h after weaning.Indices include early diastolic left atrioventricular valve blood flow Velocity（E）/early diastolic left atrioventricular annulus velocity（e’）,left ventricular ejection fraction（LVEF）,pulmonary ultrasound score（LUS）,inferior vena cava variability（△DIVC）,diaphragm displacement（DE）.Calculate the rapid shallow breathing index（RSBI）.Collect the N-terminal pro-brain natriuretic peptide（NT-pro BNP）values at T0 and T3.According to the results of weaning,patients were divided into successful weaning group and failed weaning group,and the differences of indicators were compared in the successful weaning group and the failed weaning group;use receiver operating characteristic curve（receiver operating characteristic,ROC）to evaluate the value of LUS score,E/e’,△DIVC,DE,RSBI to predict whether weaning failed;and then calculate the area under the ROC curve（AUC）,accuracy,sensitivity,specificity,positive predictive value,negative predictive value,positive likelihood ratio and negative likelihood ratio.The Clopper-Pearson method is applied to calculate the 95% CI of the corresponding value;meanwhile,LUS combined with E is evaluated based on logistic regression.The value of /e’ to test whether the weaning fails or not and the AUC of each indicator is compared using the De Long test.Pearson correlation analysis was used to analyze the correlation between LUS score and E/e’ in the successful weaning group and the failed weaning group.Results :（1）According to the success or failure of the weaning,the subjects were divided into 76 cases in the success group and 21 cases in the failure group.Through comparative analysis,it was found that there was no significant difference in the basic data of the two groups of patients（P > 0.05）.（2）LUS and E/e’ of the patients in the successful weaning group were lower than those in the failed weaning group at T0,T1,T2,and T3,but △DIVC and DE of the patients in the successful weaning group were higher than those in the failed weaning group,which shows comparative statistical difference（P < 0.05）.（3）The results of Pearson correlation analysis showed that LUS and E/e’ were positively correlated in the loser group（r=0.564,P=0.032）,LUS and E/e’ were positively correlated in the success group（r=0.478,P =0.007）.（4）ROC curve analysis results show that the accuracy,specificity,sensitivity,positive predictive value,negative predictive value,and positive likelihood ratio of LUS combined with E/e’ are all greater than E/e’,△DIVC,LUS,DE,RBSI;but LUS combined with E/e’ has the smallest negative likelihood ratio.（5）The results of De Long’s test showed that the AUC of LUS combined with E/e’ were all greater than E/e’,△DIVC,LUS,DE,and RBSI（all P < 0.05）.（6）Test results of plasma NTpro BNP concentration in the two groups of patients: NT-pro BNP levels in the successful weaning group at T1 and T3 were lower than those in the failure group（P < 0.05）,and NT-pro BNP in the failed weaning process group increased the amplitude was more significant than that of the successful group（P < 0.05）.Conclusion:Assessment method of lung ultrasound score combined with echocardiography has higher sensitivity and specificity,and has a better predictive effect on the successful weaning of patients with moderate to severe acute respiratory distress syndrome.