Study On The Correlation Between Plasma SPLA2-IIA And Airway Opening Pressure In Patients With ARDS Mechanical Ventilation

Objectives:airway closure(AC)is a common phenomenon in Acute Respiratory Syndrome(ARDS)patients and the main cause of pulmonary dysfunction,pulmonary inflammation and atelectasis.Airway closure was closely related to qualitative and quantitative loss of surfactant in alveoli.This study studied airway closure in ARDS patients and the relationship between group IIA secreted phospholipase A2(sPLA2-IIA)and airway opening pressure(AOP).To explore the relationship between different AOP and sPLA2-IIA levels,to further understand the mechanism of airway closure in ARDS,and to provide help for the optimization of mechanical ventilation.Methods:This study was a single-center,retrospective,observational clinical case study.The study subjects were 98 mechanically ventilated ARDS patients admitted to the Intensive Care Unit(ICU)of Taizhou People’s Hospital from January 2022 to February 2023,meeting the Intensive care standard.General clinical data of enrolled patients were collected and sorted out.The AOP was measured by fully sedated and analgesic muscle relaxation within the first 72 hours after endotracheal intubation,and other respiratory mechanics indexes were recorded and calculated.Meanwhile,plasma sPLA2-IIA levels were measured and clinical outcome indexes were recorded.Specific research indicators:(1)Detecting the low inflection point on the low-flow pressure-time(P-T)curve,evaluating the incidence of airway closure,and analyzing the correlation between AOP and plasma sPLA2-IIA level;(2)According to the presence of AOP,ARDS patients were divided into airway closure group(n=32)and non-airway closure group(n=66),and the differences of plasma sPLA2-IIA level,AOP and ARDS severity between the two groups were compared.(3)According to Berlin diagnostic criteria,ARDS patients were divided into mild group(n=33),moderate group(n=34)and severe group(n=31).Compare the differences of AOP,sPLA2-IIA,driving pressure(DP)and plateau pressure(Pplat)among the three groups:(4)According to 28-day mortality,the patients were divided into survival group(n=62)and death group(n=36),and the differences of AOP,sPLA2-IIA,oxygenation index(PaO2/FIO2)and APACHEII scores were compared between the two groups.Results:1.A total of 98 patients with ARDS mechanical ventilation were included in this study,among which 32 patients had airway closure,accounting for 32.65%.The median AOP value was 9.5(7.0-14.0)cmH2O.The proportion of airway closure in mild,moderate and severe ARDS groups was 12.1%,31.3%and 56.3%,respectively.2.AOP was significantly correlated with plasma sPLA2-IIA level in airway closure group(p=0.001),with a linear positive correlation(r value 0.672).3.The proportion of airway closure and plasma sPLA2-IIA level in severe ARDS are higher,and the prognosis is worse.4.Plasma sPLA2-IIA level,APACHEII score and drive pressure are independent risk factors for death in ARDS patients.Conclusions:1.Airway closure accounts for about 1/3 of mechanical ventilation patients with ARDS in ICU.The proportion of airway closure and plasma sPLA2-IIA level in severe ARDS were higher.2.AOP was positively correlated with plasma sPLA2-IIA level;Plasma was compared between the airway closure group and the non-airway closure group higher sPLA2-IIA levels were associated with worse prognosis;3.Plasma sPLA2-IIA level,APACHE Ⅱ score and drive pressure are independent risk factors for death in ARDS patients.