Mechanism Study Of PEEP Titrated In Different Methods On Right Heart Function And Pulmonary Artery Pressure In ARDS Patients

Objective:Comparison of effects of PEEP on right heart function and pulmonary artery pressure selected by ARDSnet method,EIT method and transpulmonary pressure methodMethods:A single-center prospective method was adopted in this study.In brief,from 1 June 2018 to 31February 2019,patients diagnosed ARDS who meet the inclusion were prospectively recruited into the study from the department of critical care medicine Zhongda Hospital,Southeast University,for whom clinical phenotype data,including age,gender,body weight index,underlying disease,and infection source,were collected,blood plasma samples were subsequently collected.In addition to baseline demographic data,Acute Physiology and Chronic Health Evaluation?APACHE?II scores,Sepsis-related Organ Failure Assessment?SOFA?scores were measured.PEEP was selected within three methods of ARDSnet,EIT,and transpulmonary pressure within 48 hours after diagnosis of ARDS.Then,the PEEP sequence selected by basic,ARDSnet,EIT,and transpulmonary pressure ware divided into four groups.The PEEP selected by ARDSnet,EIT,and transpulmonary pressure ware independently divided into two subgroups with a driving pressure of 15 cmH₂O and 12 cmH₂O.The ventilator parameters in the pressure control mode were set to:FIO₂ 40-80%,I:E 1:2,RR 20 times/min.Ventilator parameter was set for each group of PEEP,and each group was re-expanded with high pressure 45cmH₂Olow pressure 30cmH₂O for 35S.Each group lasted for 10min and then The patient's right heart function and pulmonary artery were detected at the interface of the four-chamber heart passed through transthoracic echocardiography?TTE?at the apex.The following data were recorded during the experiment:ARDSnet,EIT,and esophageal titration PEEP data;data for each method under PEEP settings:lung compliance,airway resistance,heart rate,blood pressure,center Venous pressure,arteriovenous blood gas,left and right ventricular diameter,tricuspid annulus systolic displacement?TAPSE?,tricuspid annulus systolic velocity?TAM?,pulmonary artery pressure.Result:1.Baseline Characteristics:A total of 25 patients with ARDS were included in this study,including moderate 14patients and severe 11 patients,excluding 3 patients with poor image quality.A total of 22 patients were included in the final study,and 10 of them received ECMO treatment.19 cases?86.36%?had moderate right ventricular enlargement and 3 cases?13.63%?had severe right ventricular enlargement under basic PEEP 5cmH₂O condition.Pulmonary hypertension was found in 1 cases?4.54%?.The PEEP values of ARDSnet,EIT and transpulmonary pressure titration were 10.00?8.00,10.00?,12.00?10.00,14.00?and 12.00?9.00,14.00?cmH₂O,respectively.The PEEP values of ARDSnet titration were significantly lower than those of EIT and esophageal pressure titration?P=0.002,P=0.022?.2.Effects of PEEP titrated in different methods on right heart function and pulmonary artery pressure:When the driving pressure was 15cmH₂O,the PEEP ventilation of ARDSnet,EIT and transpulmonary pressure groups significantly decreased compared with that of the 5cmH₂O PEEP group?20.91±5.40 vs 24.98±5.42,P=0.01?.21.07±5.39 vs 24.98±5.42,P=0.013;21.31±4.96 vs 24.98±5.42,P=0.02).The transpulmonary pressure group was significantly lower than the basic group?14.19±2.47 vs 16.11±3.37,P=0.041?.There was no statistically significant difference in pulmonary artery pressure between the ARDSnet,EIT,transpulmonary pressure groups and the basic group.When the driving pressure was 12cmH₂O,the PEEP ventilation in the ARDSnet,EIT and transpulmonary pressure groups was significantly lower than that in the 5cmH₂O PEEP group?22.92±4.94 vs 24.98±5.42,P=0.01?.22.01±6.05 vs 24.98±5.42,P=0.013;22.29±5.61 vs 24.98±5.42,P=0.02).Compared with the basic group,TAM was significantly lower[14.80?12.65,17.90?)vs.16.64?14.01,18.05?,P=0.039].There was no statistically significant difference in pulmonary artery pressure between the ARDSnet,EIT,transpulmonary pressure groups and the basic group.Under the same PEEP condition,compared with the driving pressure of 15cmH₂O,the TAPSE of ARDS net group and transpulmonary pressure group was significantly increased when the driving pressure was 12cmH₂O,respectively?20.91±5.40 vs 22.92±4.94,P=0.012?.21.31±4.96 vs 22.29±5.61,P=0.038).TAM was significantly increased in the transpulmonary pressure group and EIT group?14.19±32.47 vs 14.96±2.69,P=0.03?.21.31±4.96 vs 22.29±5.61,P=0.03).There was no statistically significant difference in pulmonary artery pressure between ARDS net group,EIT group and transpulmonary pressure group.3.Effects of PEEP titrated in different methods on hemodynamics:When the driving pressure was 15 and12cmH₂O respectively,there was no significant difference in systolic blood pressure,diastolic blood pressure,mean arterial pressure and central venous pressure between the ARDSnet,EIT and transpulmonary pressure groups under PEEP ventilation compared with the basic 5cmH₂O PEEP group.Under the same PEEP condition,compared with the driving pressure of 15cmH₂O,the hemodynamic differences in ARDS net group,EIT group and transpulmonary pressure group under the driving pressure of12cmH₂O were not statistically significant.4.Effects of PEEP titrated by different methods on blood gas analysis:When the driving pressure was15cmH₂O,the oxygen partial pressure and oxygenation index of the three groups of ARDSnet,EIT and transpulmonary pressure were significantly increased under PEEP ventilation compared with that of the basic5cmH₂O PEEP group,and the difference was statistically significant.When the driving pressure was 12cmH₂O,the oxygen partial pressure was significantly increased under PEEP ventilation in the transpulmonary pressure group compared with that in the basic 5cmH₂O PEEP group,and the difference was statistically significant.Under the same PEEP condition,compared with the driving pressure of 15cmH₂O,there was no significant difference in blood gas analysis between ARDS net group,EIT group and transpulmonary pressure group at the driving pressure of 12cmH₂O.5.Effects of PEEP titrated by different methods on right heart function and pulmonary artery pressure in patients with non-ecmo treatment:When the driving pressure was 15cmH₂O,the PEEP ventilation in EIT group was significantly lower than that in the 5cmH₂O PEEP group,and the difference was statistically significant?25.7±6.75 vs 20.54±5.39,P=0.032?.Compared with the basic 5cmH₂O PEEP group,the transpulmonary pressure group had significantly lower TAM and the difference was statistically significant?17.43±3.14 vs 15.08±2.64,P=0.045?.There was no statistically significant difference in pulmonary artery pressure between the ARDSnet,EIT,transpulmonary pressure groups and the basic group.When the driving pressure was 12cmH₂O,there was no statistically significant difference in right heart function and pulmonary artery pressure between ARDSnet,EIT and the transpulmonary pressure group under PEEP ventilation compared with the basic 5cmH₂O PEEP group.Under the same PEEP condition,compared with the driving pressure of 15cmH₂O,when the driving pressure was 12cmH₂O,the TAPSE of EIT group and transpulmonary pressure group was significantly increased and the difference was statistically significant?20.54±5.39 vs 23.53±4.96,P=0.02?.21.71±4.91 vs 23.56±5.67,P=0.02).TAM was significantly increased in the EIT group and the transpulmonary pressure group,and the difference was statistically significant?15.88±2.56 vs 17.69±1.47,P=0.03?.15.08±2.38 vs 16.25±2.35,P=0.02).6.Effects of PEEP titrated by different methods on hemodynamics in patients with non-ecmo treatment:When the driving pressure was 15 and 12cmH₂O respectively,there were no statistically significant differences in systolic blood pressure,diastolic blood pressure,mean arterial pressure and central venous pressure between the ARDSnet,EIT and transpulmonary pressure groups under PEEP ventilation compared with the basic5cmH₂O PEEP group.Under the same PEEP condition,compared with the driving pressure of 15cmH₂O,the hemodynamic differences in ARDS net group,EIT group and transpulmonary pressure group under the driving pressure of12cmH₂O were not statistically significant.7.Influence of PEEP titrated by different methods on blood gas analysis in non-ecmo patients:When the driving pressure was 15 and 12cmH₂O respectively,the oxygen partial pressure was significantly increased under PEEP ventilation in the transpulmonary pressure group compared with that in the basic 5cmH₂O PEEP group,and the difference was statistically significant.Under the same PEEP condition,compared with the driving pressure of 15cmH₂O,there was no significant difference in blood gas analysis indexes between ARDS net group,EIT group and transpulmonary pressure group at the driving pressure of 12cmH₂O.8.There were no statistically significant differences in right heart function and blood gas indexes among ARDS patients receiving ECMO treatment under different PEEP methods and driving pressure conditions.Conclusion:Right ventricular dilatation is a common complication of moderate to severe ARDS.There were differences in the three methods of ARDSnet,EIT and esophageal pressure for titration of PEEP.ARDSnet,EIT,and esophageal pressure titration PEEP affect right ventricular systolic function in patients with moderate to severe ARDS.In patients treated with ECMO,PEEP has no significant effect on right heart function in patients with moderate to severe ARDS.