Abstract:Objective To observe the expression of mucoprotein MUC5AC in respiratory tract of patients with ventilator-associated pneumonia (VAP) and the clinical value. Methods A total of 63 patients received mechanical ventilation in the intensive care unit (ICU) of Anqing Hospital Affiliated to Anhui Medical University from April 2018 to March 2019 were selected as study subjects. The subjects were divided into experimental group (VAP group) and control group (non-VAP group) according to the diagnostic criteria of VAP formulated by the Chinese society of critical care medicine. After endotracheal intubation at 1 h and 48 h, alveolar lavage fluid was collected by fiberoptic bronchoscopy, and MUC5AC content of mucin in lavage fluid was determined by enzyme linked immunosorbent assay, and a simplified clinical pulmonary infection score (CPIS) was calculated. MUC5AC level and CPIS score were compared between the two groups, and the correlation between MUC5AC expression level and CPIS score was analyzed. MUC5AC level and CPIS score of the two groups had no significant difference after 1 h of intubation (P > 0.05). MUC5AC level and CPIS score in the experimental group were higher than those in the control group (P < 0.05). The expression level of MUC5AC mucin and CPIS score in the experimental group were significantly higher than that in the experimental group at 48 h after intubation (P < 0.01). The expression level of MUC5AC in the control group was also higher than that in the control group at 48 h after intubation (P < 0.05), while CPIS score had no significant difference between 48 h and 1 h after intubation (P > 0.05). MUC5AC expression level was positively correlated with CPIS score in all patients (r = 0.782, P < 0.05). Conclusion MUC5AC is highly expressed in respiratory tract of ventilator-associated pneumonia patients. Mechanical ventilation also plays an important role in MUC5AC oversecretion.