Correlation Between Mechanical Ventilation Pressure Parameters And Early Prognosis Of Patients With Acute Respiratory Distress Syndrome

Objective1.To explore the correlation between pressure parameters in pressure-controlled mechanical ventilation mode and early prognosis of patients with acute respiratory distress syndrome,and to determine the target drive pressure and platform pressure,so as to reduce the occurrence of ventilators associated lung injury.2.The driving pressure,platform pressure,Apache II score,LAC level,and PEEP were compared to evaluate the predictive ability of the above indicators on the prognosis of ARDS patients with pressure-controlled ventilation mode.Methods1.199 ARDS patients treated in the First Affiliated Hospital of Zhengzhou University from January 2018 to January 2020 were selected.2.The demographic characteristics of patients: age and gender were collected retrospectively through HIS system in hospital;the primary disease causing ARDS;APACHE II score;the arterial blood gas analysis indexes within 24 hours after patients were included in the study: arterial blood p H(p H),arterial oxygen partial pressure(Pa O2),arterial carbon dioxide partial pressure(Pa CO2)and arterial lactic acid(Lac);the related parameters of mechanical ventilation on ventilator include respiratory rate(RR),inhaled oxygen concentration(Fi O2),positive end-expiratory pressure(PEEP)and platform pressure(pplat);blood routine record index: WBC,PLT;infection indicators: including C-reactive protein(CRP)and procalcitonin(PCT);coagulation function indexes: fibrinogen(Fib)and plasma D-dimer;The respiratory oxygenation index(Fi O2/Pa O2)was calculated.Calculate the driving pressure(Δp = pplat-peep);Mechanical ventilation days of suction machine;Hospital stay in ICU.3.The outcome index of the patient,that is,28-day and 90-day survival index,was obtained by telephone follow-up from July to September 2020.The main outcome index of this study was 28-day mortality after the occurrence of ARDS,while 90-day mortality,days of mechanical ventilation and length of stay in ICU were secondary outcome indicators.4.The outcome index of the patient,that is,28-day and 90-day survival index,was obtained by telephone follow-up from July to September 2020.The main outcome index of this study was 28-day mortality after the occurrence of ARDS,while 90-day mortality,days of mechanical ventilation and length of stay in ICU were secondary outcome indicators.Results1.According to the inclusion and exclusion criteria,our study included a total of199 ARDS patients with pressure-controlled mechanical ventilation,93 died on the28 th day,106 survived,and the 28-day fatality rate was 46.7%.113 cases died in 90 days,86 cases survived,and the 90-day fatality rate was 56.8%.There was no significant difference in mortality between patients with pulmonary ARDS and those with extrapulmonary ARDS(χ2 =1.335,P=0.248).2.Through the one-way ANOVA,we can see that the driving pressure of the dead group is significantly higher than that of the survival group [(18.36 ±4.02)VS.(15.55 ±3.26)],and there is a significant difference between the two groups(P < 0.05).The platform pressure,APACHEII score,respiratory rate and arterial lactic acid Lac were compared between the two groups [(25.60 ±5.13)VS.(21.85 ±4.64),(24.87±5.03)VS.(17.77 ±4.86)],(22.40 ±5.78)VS.(19.64 ±4.67)] and(2.62 ±2.76)VS..(1.58 ±1.47),the death group was significantly higher than the survival group,and there was significant difference between the two groups(P < 0.05).The oxygenation index [(94.72 ±51.11)VS.(137.09 ±60.68)] in the survival group was significantly higher than that in the death group,and there was significant difference between the two groups(P < 0.05).The mechanical ventilation time and ICU hospitalization time in the death group were significantly higher than those in the survival group,and there was significant difference between the two groups.According to the severity of ARDS,the patients were divided into three groups.The driving pressure of mild,moderate and severe patients was(14.82±3.568)、(16.61±3.926)and(17.53±3.764)cm H2 O,respectively.The plateau pressure was(21.14 ±4.346),(22.93 ±4.985)and(24.73 ±5.336)cm H2 O,respectively,and there was significant difference between the two groups(P < 0.05).There was no significant difference in positive end-expiratory pressure among mild,moderate and severe ARDS patients.3.Multivariate Cox regression model showed that age,driving pressure(ΔP),APACHEⅡ score and Lac were the risk factors for 28-day prognosis of patients with acute respiratory distress syndrome(ARDS),which were correlated with short-term adverse prognosis.ROC curve analysis showed that APACHEⅡscore(AUC=0.842)and oxygenation index(AUC=0.720)were the best predictors,while Lac arterial blood gas lactic acid(AUC=0.684)was slightly worse.Among the mechanical ventilation pressure parameters,driving pressure(AUC=0.706)and platform pressure(AUC=0.711)have the best predictive ability,while positive end-expiratory pressure(AUC=0.0.581)has the worst predictive effect.4.Kaplan-Meie survival curve analysis showed that the cumulative survival rate of ARDS patients with high driving pressure level(ΔP>16 cm H2O)without endpoint events was significantly lower than that of ARDS patients with low driving pressure level(ΔP≤16cm H2O),and the difference between the two groups was statistically significant(Log Rank test: 2=26.92,P<0.001).The cumulative survival rate of ARDS patients without endpoint events in high plateau pressure group(ΔP>22cm H2O)was significantly lower than that in low plateau pressure group(ΔP≤22cm H2O),and the difference between the two groups was statistically significant(Log-Rank test:2=18.47,P<0.0001)Conclusion1.In the pressure-controlled mode of lung protective ventilation strategy,high driving pressure and high plateau pressure are the risk factors of patients’ early survival state,so it is recommended to control the level of driving pressure below16.5cm H2O;too high plateau pressure is not conducive to the early prognosis of patients,and it is recommended to control the level of plateau pressure below22 cm H2O.2.Among the pressure parameters of mechanical ventilation,the early prognostic value of plateau pressure in patients with ARDS is greater than that of driving pressure.