Study On The Clinical Effect Of Transpulmonary Pressure Guided PEEP Titration In Patients With ARDS

Objective:To investigate the effects of optimal positive end-expiratory pressure（PEEP）titration with transpulmonary pressure（Ptp）on hemodynamics,pulmonary edema,gas exchange and respiratory mechanics in patients with acute respiratory distress syndrome（ARDS）.Methods:Sixteen patients with moderate and severe ARDS admitted to the Department of intensive Care Medicine of the third Hospital of Hebei Medical University from September 2019 to January 2020 were randomly divided into two groups:transpulmonary pressure group（n=8）and ARDSnet group（n=8）.In the transpulmonary pressure group,the end-expiratory transpulmonary pressure（Ptp-e）>0 was used as the target value to monitor the esophageal pressure to titrate the PEEP value,and the PEEP titration in the ARDSnet group was performed according to the ARDS collaboration network（ARDSnet）.The indexes of hemodynamics,pulmonary edema,gas exchange and respiratory mechanics at D0,12H,D1,D2,D3 and D5 were measured and recorded,and the time of mechanical ventilation and 28-day mortality were recorded.Results:A total of 16 patients were enrolled in this study,including transpulmonary pressure group（n=8）and ARDSnet group（n=8）.There was no significant difference in sex,age,height,weight and severity of illness between the two groups（P>0.05）.In terms of hemodynamics,there was no significant difference in hemodynamic indexes between the two groups at each time point（D0、12H、D1、D2、D3、D5）（P>0.05）,and there were no adverse reactions such as barotrauma between the two groups.In terms of pulmonary edema index,there was no significant difference in extravascular lung water index（EVLWI）and pulmonary vascular permeability index（PVPI）,between the two groups（P>0.05）.In terms of gas exchange,the Pa O₂ of transpulmonary pressure group was higher than that of ARDSnet group,and the difference was statistically significant（P<0.05）;There was no significant difference in p H、Pa CO₂ results（P>0.05）.In terms of respiratory mechanics,the PEEP titrated by transpulmonary pressure method was significantly higher than that of PEEP titrated by ARDSnet method（10±1 vs 8±2,P=0.011）,and the indexes of transpulmonary pressure method were higher than those of ARDSnet method,such as oxygenation index（OI）（225±80 vs 158±41,P=0.043）,end-expiratory transpulmonary pressure（Ptp-e）（1.5±0.7vs-0.5±1.1,P=0.001）,lung tissue compliance（C_L）（73±14 vs 55±17,P=0.047）.The difference was statistically significant.However,there was no significant difference in end-inspiratory transpulmonary pressure between transpulmonary pressure method and ARDSnet method（4.9±1.3 vs 5.6±3.7,=0.621）.There was no significant difference in platform（Pplat）,end-expiratory esophageal pressure（Pes-e）,end-inspiratory transpulmonary pressure（Ptp-i）,respiratory system driving pressure（ΔP）,transpulmonary driving pressure（ΔP_L）,respiratory system compliance（Crs）and chest wall compliance（Ccw）（P>0.05）.In terms of curative effect index,the 28-day fatality rate of transpulmonary pressure group was 25.0%and that of dint ARDSnet group was 37.5%,and the difference was not statistically significant（P>0.05）;There was no significant difference in the duration of mechanical ventilation between the two groups（11.6±3.8 vs 12.3±42.2）（P>0.05）.Conclusion:1.For moderate and severe patients with ARDS,the best PEEP of transpulmonary pressure titration is higher than that of ARDSnet titration during mechanical ventilation,which can significantly improve the oxygenation index and lung function of ARDS patients.2.Transpulmonary pressure method can significantly improve oxygenation in patients with moderate and severe ARDS.Although there is no significant difference in Crs compared with ARDSnet method,C_L is significantly improved,and has little effect on hemodynamics,so it can be used as one of lung protective ventilation strategies.3.There was no significant difference in 28-day mortality between transpulmonary pressure method and ARDSnet method in patients with moderate and severe ARDS.Whether transpulmonary pressure can improve the prognosis of patients needs further study.