摘要目的:探讨恶性肿瘤患者呼吸机相关性肺炎（VAP）与机械通气前中性粒细胞/淋巴细胞比值（NLR）的关联性。方法:采用回顾性巢式病例对照设计研究方法，选择2015年2月至2020年2月贵州医科大学第三附属医院收治并接受机械通气治疗的恶性肿瘤患者。以发生VAP患者作为病例组，按1∶2比例匹配非VAP患者作为对照组。收集患者临床资料，比较两组各指标的差异，并用多因素Logistic回归分析恶性肿瘤患者发生VAP的影响因素。结果:研究期间进行机械通气治疗的恶性肿瘤患者1 271例，其中241例发生VAP，VAP发生率为18.96%。病例组有232例VAP患者匹配成功，对照组为464例非VAP患者。两组年龄、性别、入院诊断、原发性肿瘤、区域淋巴结和远处转移（TNM）分期、急性生理学与慢性健康状况评分Ⅱ（APACHEⅡ）、合并症、机械通气时间、血红蛋白（Hb）和血清白蛋白（Alb）水平等临床资料均衡可比，且集束化护理措施具有一致性。与对照组比较，病例组虽然中性粒细胞计数（NEU）和淋巴细胞计数（LYM）差异无统计学意义〔NEU（×10 9/L）：3.81±1.07比3.64±1.05，LYM（×10 9/L）：2.06±0.59比2.15±0.62，均 P>0.05〕，但NLR却明显升高（2.07±1.05比1.89±0.96， P<0.05），住院时间也明显延长（d：24.84±3.81比13.19±3.98， P<0.01）。将NLR、性别、年龄、APACHEⅡ评分、TNM分期、Hb、血清Alb、机械通气时间纳入多因素Logistic回归分析显示，NLR升高患者发生VAP风险较大〔优势比（ OR）＝1.187，95%可信区间（95% CI）为1.015～1.387， P＝0.032〕。发生VAP患者中，NLR与VAP发生前机械通气时间呈负相关（ r＝-0.327， P＝0.000），与VAP发生后使用抗菌药物时间呈正相关（ r＝0.559， P＝0.000）。 结论:恶性肿瘤机械通气患者NLR升高可显著增加VAP发生风险，治疗难度加大。

abstractsObjective:To explore the relationship between ventilator-associated pneumonia (VAP) and neutrophil/lymphocyte ratio (NLR) before mechanical ventilation in patients with malignant tumors.Methods:A retrospective nested case-control study was conducted. Patients with malignant tumor treated by mechanical ventilation admitted to the Third Affiliated Hospital of Guizhou Medical University from February 2015 to February 2020 were enrolled. The patients with VAP were selected as the case group, and the matched non-VAP cases were selected according to 1∶2 as the control group. The clinical data were collected, and the differences of each index between the two groups were compared. The influencing factors of VAP in patients with malignant tumor were analyzed by multivariate Logistic regression.Results:During the study period, 1 271 patients with malignant tumors were treated with mechanical ventilation, of which 241 cases had VAP, and the incidence of VAP was 18.96%. There were 232 VAP patients in the case group matched 464 non-VAP patients in the control group. The clinical data of age, gender, hospitalization diagnosis, primary tumor, regional lymph node and distant metastasis (TNM) stage, acute physiology and chronic health evaluation Ⅱ (APACHEⅡ), complications, duration of mechanical ventilation, hemoglobin (Hb) and serum albumin (Alb) levels were balanced and comparable between the two groups, and the cluster nursing measures were consistent. Compared with the control group, although there was no significant difference in neutrophil count (NEU) and lymphocyte count (LYM) in the case group [NEU (×10 9/L): 3.81±1.07 vs. 3.64±1.05, LYM (×10 9/L): 2.06±0.59 vs. 2.15±0.62, both P > 0.05], NLR was significantly increased (2.07±1.05 vs. 1.89±0.96, P < 0.05), and the hospital stay was significantly longer (days: 24.84±3.81 vs. 13.19±3.98, P < 0.01). NLR, gender, age, APACHEⅡ score, TNM stage, Hb, serum Alb and duration of mechanical ventilation were included in multivariate Logistic regression analysis. The results showed that patients with elevated NLR had higher risk of VAP [odds ratio ( OR) = 1.187, 95% confidence interval (95% CI) was 1.015-1.387, P = 0.032]. In patients with VAP, NLR was negatively correlated with the time of mechanical ventilation before VAP (r = -0.327, P = 0.000), and positively correlated with the time of treatment with antibiotics after VAP (r = 0.559, P = 0.000). Conclusion:Elevated NLR in patients with malignant tumors who were on mechanical ventilation can significantly increase the risk of VAP and increase the difficulty of treatment.