Application Value Of The Serum Level Of Interleukin-17 And Lung Ultrasound Score In Early Prediction Of Neonatal Ventilator-associated Pneumonia

ObjectiveNeonatal ventilator-induced lung injury(VILI)refers to in the process of the treatment of mechanical ventilation,due to improper parameter adjustment,not matched with individual lung and so on,neonates develop a series of complications of impaired lung function such as oxygenation dysfunction and pulmonary edema.Ventilator-associated pneumonia(VAP),pneumothorax,pulmonary hemorrhage,and bronchopulmonary dysplasia(BPD)are the most common lung injuries seen in neonates.At present,the most common VILI is ventilator-associated pneumonia(VAP).Studies indicate that the incidence of early onset VAP is 3.33%,the incidence of late onset VAP is 11.67%,and the fatality rate is 8.33%.Neonatal VAP often increases the use rate and intensity of antibiotics,prolongs mechanical ventilation,oxygen therapy and hospital stay,and increases the cost of hospital stay.In severe cases,it can directly lead to death of children.Interleukin 17(IL-17)is the main effector lymphocyte secreted by helper T lymphocyte-17(TH17).It is a proinflammatory cytokine that plays a pro-inflammatory role in the early stage of bacterial and viral infection by activating transcription factors and mitogen-activated protein kinases,promoting the release of a variety of inflammatory factors by cells.Lung ultrasound is based on ultrasound artifacts to analyze lung lesions,using color Doppler ultrasound instrument for ultrasound examination.Compared with adults,neonates have many advantages,such as low degree of rib ossification,thin chest wall,small lung volume,small body surface area and so on.Lung ultrasound is easy to operate and no radiation,can be used for bedside diagnosis and provide real-time images.It has a high application prospect in neonatal lung diseases,and the development of ultrasound technology has been great in recent years.Lung ultrasound has become a new monitoring method respected in intensive care units(ICU).By comparing the serum level of Interleukin-17,lung ultrasound score at different time points after mechanical ventilation,and comparing the expression differences between VAP group and non-VAP group,this study aims to explore the application value of the serum level of Interleukin-17 and lung ultrasound score in the early prediction of neonatal VAP,in order to find out new ideas and monitoring methods to diagnose and intervene neonatal VAP in time.Methods1.A total of 57 neonates with mechanical ventilation admitted to the Neonate Intensive Care Unit(NICU)of Northern Jiangsu Peolple’s Hospital from January 2019 to January 2021 were selected as the research subjects.Neonates with the following conditions were excluded:(1)prenatal diagnosis of chromosomal abnormalities,hereditary lung diseases;(2)congenital respiratory malformation;(3)The mother had infectious diseases such as chorioamnitis;(4)Death during hospitalization or abandonment(interruption)of treatment.All the neonates were divided into VAP group and non-VAP group according to the diagnostic criteria of neonatal VAP.2.All the children were treated with heparin tubes to collect 1.5 milliliter of peripheral venous blood at 0h,48h and 72h after mechanical ventilation.The samples were left standing at indoor temperature for 15-25 minutes,and centrifuged at 3000r/min for 15minutes.After centrifugation,the upper serum was collected by pipet and stored in a refrigerator at-20℃ for use.Enzyme linked immunosorbent assay(ELISA)was used to determine the serum level of IL-17.The specific procedures are strictly in accordance with the kit instructions,and all samples are tested by the same doctor in charge of the laboratory.3.Lung ultrasound was performed for all children at the corresponding 3 time points(0h,48h and 72h after mechanical ventilation),and lung ultrasound score(LUS)were performed.All examinations were performed by the same physician who had received lung ultrasound training for more than half a year.4.Results of routine examinations,such as blood cell analysis and chest X-ray,were recorded,and the severity of the disease was assessed by clinical pulmonary infection score(CPIS)based on clinical signs,imaging and laboratory examinations.5.The obtained data were analyzed by SPSS24.0 software,and the normal distribution and homogeneity of variance were first tested for all the continuity variables.Continuous variables were expressed as mean±standard deviation(x± s),and independent sample t test was used for comparison between groups.Count data were described by frequency,and comparison between groups was performed by chi-square test.Repeated measurement analysis of variance was used for comparison at different time points within the group.Pearson correlation analysis was used to describe the correlation between the variables.The ROC curve was drawn and the sensitivity and specificity were calculated to compare value of single index and combined index for early prediction of VAP.Results1.A total of 57 cases of premature infants were included in this study,among which 3 cases died or gave up treatment midway.A total of 54 patients had complete data,including 30 in the VAP group and 24 in the non-VAP group.The general information of the two groups:gestational age,sex,body length,birth weight and delivery mode were compared,and the differences were not statistically significant(P>0.05).2.The serum level of IL-17 of VAP group was higher than that of non-VAP group at Oh,48h and 72h,but there was no statistically significant difference between the two groups at 0h(P>0.05),and the differences were statistically significant between the two groups at 48h and 72h(P<0.01).The serum level of IL-17 in VAP group was significantly increased with the prolongation of mechanical ventilation time,and the differences were statistically significant between 48h and 0h and between 72h and 48h(P<0.01).The serum level of IL-17 in non-VAP group was also slightly higher than before,but there was no statistical significance between 48h and 0h and between 72h and 48h(P>0.05).3.Comparison of lung ultrasound score in the two groups at 0h,48h and 72h showed that lung ultrasound score of VAP group were higher than that of non-VAP group,but there was no statistically significant difference between the two groups at 0h(P>0.05),and there was statistically significant difference between the two groups at 48h and 72h(P<0.01).With the extension of mechanical ventilation time,LUS of VAP group at 48h was lower than 0h and LUS at 72h was higher than 48h,and there was statistically significant difference at different time points(P<0.05).LUS of non-VAP group showed a decreasing trend,48h was lower than 0h,and the difference was statistically significant(P<0.05).LUS of non-VAP group at 72h was lower than 48h,but the difference was not statistically significant(P<0.05).4.The serum level of IL-17 was positively correlated with CPIS(r=0.804,P<0.01)and LUS was positively correlated with CPIS(r=0.695,P<0.01).5.The areas under the ROC curve of CPIS,the serum level of IL-17,LUS,the serum level of IL-17 combined with LUS in early prediction of neonatal VAP were 0.872,0.776,0.836,0.865;the sensitivity were 0.862,0.707,0.724,0.828;the specificity were 0.760,0.741,0.880,0.843.Conclusions1.The serum level of IL-17 and lung ultrasound score(LUS)were positively correlated with clinical pulmonary infection score(CPIS);Both the serum level of IL-17 and lung ultrasound score(LUS)can be used as early prediction indexes of neonatal VAP.2.Both the serum level of IL-17 and LUS can predict the occurrence of neonatal VAP in early stage.However,the clinical application value of the serum level of IL-17 combined with LUS in predicting neonatal VAP is better than that of single the serum level of IL-17 and LUS,with high specificity and sensitivity.