观察机械通气患者呼吸机管路细菌污染以及对呼吸机相关性肺炎的影响

Bacterial contamination of ventilator circuit and its influence on ventilator associated pneumonia in mechanically ventilated patients

目的：观察重症监护病房（ ICU）内机械通气患者呼吸机管路细菌污染状态以及呼吸机管路更换对呼吸机相关性肺炎（ VAP）发生率的影响，为合理进行呼吸机管路管理提供依据。方法将ICU内161例机械通气患者根据换管时间分组，其中81例患者每天分别进行呼吸机管路不同部位细菌培养、痰培养，比较细菌生长率的情况；对不同组间VAP的发生率及预后进行比较。结果呼吸机管路细菌以革兰阴性菌为主，管路与人工气道接口处细菌生长率（84．65％）最高（P＜0．01），进气管路细菌培养与痰培养一致率（41．49％）较低（P＜0．01）；呼吸机进气管路、出气管路、与人工气道接口处细菌生长均与时间呈正相关，相关系数（ r）分别为0．9694、0．9082、0．6384。细菌生长的时间先后顺序依次为人工气道接口处、出气管路、进气管路。不同换管时间患者VAP的发生率及预后比较差异无统计学意义（P＞0．05）。结论机械通气患者呼吸机管路细菌污染率高，但调整更换呼吸机管路的更换周期对VAP的发生率无影响。

Objective To survey the status of ventilator circuit with bacterial contamination and the influence on morbidity of VAP associated with ventilator circuit changes in mechanically ventilated patients.Methods According to the frequency of ventilator circuit changes, 161 patients with mechanical ventilation in ICU were divided into different groups.Bacterial culture of different locations in ventilator circuit and sputum culture were made every day in 81 patients in order to compare the rate of bacterial growth, the difference of morbidity of VAP and prognosis.Results Gram-negative bacteria is superior in ventilator circuit.Statistically, the rate of bacterial growth （ 84.65%） was the highest in circuit and artificial airway joints（P〈0.01）.The consistent rate of bacterial culture of inspiratory tube and sputum culture（41.49%）was low（P〈0.01）.The rates of bacterial growth in inspiratory tube, exspiratory tube and artificial airway joints are positively correlated with time （ r =0.9694, 0.9082, 0.6384） .The time sequence of bacteria growth were at the artificial airway joints, inspiratory tube and exspiratory tube.There were no statistical differences in the morbidity of VAP and prognosis among in the groups which were divided by frequency of ventilator circuit changes（ P〉0.05） .Conclusion The rate of ventilator circuit with bacterial contamination in mechanically ventilated patients is high, but it has no effect on the morbidity of VAP by adjusting the frequency of ventilator circuit changes.