Diagnosis and prognosis evaluation value of neutrophil elastase in ventilator-associated pneumonia / 中华危重病急救医学

ABSTRACT

Objective To investigate the diagnosis and prognosis evaluation value of neutrophil elastase (NE) in ventilator-associated pneumonia (VAP).Methods A retrospective analysis was conducted.The data of patients undergoing mechanical ventilation admitted to Department of Central Intensive Care Unit (ICU) of Boai Hospital of Zhongshan City Affiliated to Southern Medical University from September 2012 to October 2015 were enrolled.The patients were divided into two groups according to whether they suffered from VAP or not.The content of NE in serum and bronchoalveolar lavage fluid (BALF) at the time of mechanical ventilation start,VAP diagnosis (the worst value from 48 hours after mechanical ventilation start to weaning in non-VAP patients),and at the time before mechanical ventilation weaning,as well as inflammation parameters,clinical pulmonary infection score (CPIS),duration of mechanical ventilation and prognosis were recorded.Receiver operating characteristic curve (ROC) was used to analyze the predictive value of NE on VAP diagnosis and prognosis.Results Finally 38 patients were enrolled in the VAP group,and 40 in non-VAP group,and baseline data was similar between the two groups.There was no significant difference in the content of NE in serum and BALF between VAP group and non-VAP group [serum NE (μg/L)67.04 (63.00,75.75) vs.69.00 (63.75,75.00),BALF NE (μg/L)96.26 (85.26,176.01) vs.95.26 (86.76,107.11),both P ＞ 0.05].From continuous monitoring,no significant change in the content of NE in serum and BALF during mechanical ventilation was found in the non-VAP group,but the content of NE in serum and BALF at the time of VAP diagnosis in VAP group was significantly higher than that at mechanical ventilation start [μg/L157.00 (153.04,165.75) vs.67.04 (63.00,75.75),178.04 (153.00,188.25) vs.96.26 (85.26,176.01),both P ＜ 0.05],and NE content in serum and BALF was significantly decreased at the time after VAP clinical recovery and before mechanical ventilation weaning [μg/L75.67 (64.51,110.55) vs.157.00 (153.04,165.79),95.50 (66.56,183.02) vs.178.04 (153.00,188.25),both P ＜ 0.05].The NE in the start time of VAP in VAP group was divided into four groups according to quartile,it was found that with the increase of NE content in serum and BALF,the CPIS was increased,the duration of mechanical ventilation was prolonged,and the prognosis was poor (all P ＜ 0.01).Compared with non-VAP group,white blood cell count (WBC),neutrocyte proportion,C-reactive protein (CRP),and procalcitonin (PCT) in VAP group were significantly increased (all P ＜ 0.01).NE in BALF was significantly positively correlated with WBC,neutrocyte proportion,CRP and PCT (r value was 0.507,0.432,0.779,and 0.519,respectively,all P =0.000),among which the highest correlation was CRP.NE in BALF used for VAP diagnosis has good accuracy,with sensitivity of 87.4％,and specificity of 90.6％,and sensitivity and specificity of NE in serum for VAP diagnosis was 78.6％ and 79.2％ respectively.Conclusion NE can be used as one of the indicators for VAP diagnosis,and it is related to the prognosis of VAP.