探讨支气管肺泡灌洗液α-淀粉酶在早期评估呼吸机相关肺炎(ventilator-associated pneumonia, VAP)风险的应用价值，分析导致VAP发生的危险因素。

选取2017年7月至2019年12月中国中医科学院西苑医院ICU收治的行气管插管机械通气的患者185例，收集患者临床资料，对所有患者在入ICU第3天行纤维支气管镜肺泡灌洗检查，检测支气管肺泡灌洗液中α-淀粉酶水平；根据患者气管插管机械通气第3～14天内是否发生VAP分为VAP组和非VAP组，比较两组患者临床资料、α-淀粉酶水平，采用多因素logistic回归方程分析导致VAP发生的独立危险因素；绘制受试者工作特征曲线(ROC)，分析α-淀粉酶在早期预测VAP中的诊断效能。

185例患者共发生37例VAP，发生率为20.00%；比较两组临床资料显示，VAP组误吸危险因素数量、GCS评分、低蛋白血症比例、机械通气时间、应用催眠镇静药和质子泵抑制剂比例以及支气管肺泡灌洗液中α-淀粉酶水平与非VAP组比较存在统计学差异(P<0.05)；多因素Logistic回归分析显示，存在误吸危险因素数量≥3个(OR＝45.086)、低蛋白血症(OR＝40.718)、机械通气时间越长(OR＝1.464)、气管肺泡灌洗液中α-淀粉酶水平越高(OR＝1.016)是导致VAP发生的独立危险因素(P<0.05)；ROC曲线分析显示，α-淀粉酶水平在早期预测VAP发生的曲线下面积为0.887，高于误吸危险因素数量≥3个(AUC＝0.733)、低蛋白血症(AUC＝0.652)和机械通气时间(AUC＝0.664)，最佳截点值为580.90 U/L，预测VAP发生的敏感度为94.59%，特异度为75.00%。

气管插管机械通气患者入院时误吸风险数量越多、机械通气时间越长、合并低蛋白血症以及支气管肺泡灌洗液中α-淀粉酶水平越高，其发生VAP的风险就越大，支气管肺泡灌洗液中α-淀粉酶可作为评估机械通气患者VAP发生风险的新生物学标志物。

To explore the application value of bronchoalveolar lavage fluid α-amylase in early assessment of ventilator-associated pneumonia (VAP) risk, and to analyze the risk factors leading to VAP.

F 185 patients who underwent tracheal intubation and mechanical ventilation who were admitted to the ICU of Xiyuan Hospital of the Chinese Academy of Chinese Medical Sciences from July 2017 to December 2019 were selected, clinical data were collected, and all patients underwent fibrobron choscope alveolar lavage examination on the third day of ICU admission. To detect the level of α-amylase in bronchoalveolar lavage fluid; According to whether VAP occurred within 3 to 14 days of endotracheal intubation mechanical ventilation, patients were divided into VAP group and non-VAP group. The clinical data and α-amylase levels of the two groups were compared. The independent risk of VAP was analyzed by multivariate logistic regression equation analysis. factor; The receiver operating characteristic curve (ROC) was drawn to analyze the diagnostic efficacy of α-amylase in the early prediction of VAP.

A total of 37 cases of VAP occurred in 185 patients, and the incidence rate was 20.00%; comparing the clinical data of the two groups showed that the number of risk factors for aspiration of the VAP group, GCS score, hypoproteinemia rate, mechanical ventilation time, hypnotic sedation and The proportion of proton pump inhibitor and the level of α-amylase in bronchoalveolar lavage fluid were statistically different from those in non-VAP group (P<0.05); Multivariate logistic regression analysis showed that there were ≥3 risk factors for aspiration (OR=45.086), hypoproteinemia (OR=40.718), the longer the mechanical ventilation time (OR=1.464), α in tracheal alveolar lavage fluid -The higher amylase level (OR=1.016) is an independent risk factor for the occurrence of VAP (P<0.05); ROC curve analysis showed that the area under the curve of α-amylase level in the early prediction of VAP was 0.887, which was higher than the number of risk factors for aspiration ≥3 (AUC=0.733), hypoproteinemia (AUC=0.652) and mechanical ventilation Time (AUC=0.664), the best cut-off value is 580.90 U/L, the sensitivity to predict the occurrence of VAP is 94.59%, and the specificity is 75.00%.

The greater the number of patients who have been admitted to the hospital for tracheal intubation mechanical ventilation, the longer the risk of aspiration, the longer the mechanical ventilation time, the combined hypoproteinemia and the higher the level of α-amylase in the bronchoalveolar lavage fluid, the greater the risk of VAP Large, α-amylase in bronchoalveolar lavage fluid can be used as a new biological marker to assess the risk of VAP in patients with mechanical ventilation.