气囊上滞留物引流预防呼吸机相关性肺炎的临床研究

The clinical study of subglottic secretion drainage on the morbidity of ventilator-associated pneumonia

目的评价气管插管气囊上滞留物持续吸引(subglottic secretion drainage,SSD)对降低机械通气患者呼吸机相关性肺炎(ventilator associated pneumonia,VAP)发病率的意义。方法选择2010年1月—2011年6月入住重症医学科(intensive care unit,ICU)内预计机械通气超过72h的80例患者,分为引流组和非引流组,两组均使用可冲洗式气管插管。记录患者VAP病例数、VAP发病时间、机械通气时间、ICU住院时间、病死率、每天气囊上持续引流量,定期留取气管内痰液、气囊上滞留物进行细菌培养。结果 SSD使引流组VAP的发病率(25%)明显低于非引流组(60%)(P<0.05);引流组VAP发病的时间为(12.5±2.1)d,迟于非引流组[(5.3±2.1)d](P<0.05);两组病死率(住ICU期间)、总通气时间及住院ICU时间比较无明显差异(P>0.05);两组气囊上滞留物及下呼吸道分泌物的致病菌分布均以革兰阴性杆菌为主,主要优势菌为铜绿假单胞菌和鲍曼不动杆菌,致病菌构成比差异无统计学意义(P>0.05);35例VAP患者气囊上滞留物与下呼吸道优势菌符合率为71.4%。前5d气囊上滞留物大多数是革兰阳性球菌、肠道细菌、颊部常驻菌群,随着时间延长浓度降低,绿脓杆菌数目逐渐增多,真菌始终存在。结论气囊上滞留物是VAP病原体的重要来源,气囊上滞留物引流可降低VAP的发病率,使机械通气时VAP发病时间延迟,对病死率、总通气时间、住ICU时间及住院时间无明显影响。气囊上滞留物和下呼吸道分泌物致病菌分布以革兰阴性杆菌为主,主要优势菌为铜绿假单胞菌和鲍曼不动杆菌。

Objective To assess the significance of subglottic secretion drainage（SSD） on the incidence of ventilator-associated pneumonia（VAP） in mechanically ventilated（MV） patients.Methods From January 2010 to June 2011,80 patients who received MV estimated for more than 72 hours were intubated with a special type endotracheal tube with a small-bore cannula in the wall for SSD.The patients were randomly divided into two groups,they were received SSD and usual care non-SSD respectively.The number of cases with VAP,the time of occurrence of VAP,the duration of MV,the length of stay in hospital,mortality of VAP and the amount of subglottic secretion aspirated daily were recorded.Bacterial culture of samples from the subglottic secretions and lower respiratory tract were obtained periodically.Results The incidence rate of VAP in SSD group（25%） was less then non-SSD groups′（60%,P0.05）;The time of occurrence of VAP was delayed in SSD group [（12.5±2.1） day] compared with the non-SSD group [（5.3±2.1） day,（P0.05）];There were no significantly statistic differences for hospital mortality of VAP,overall duration of mechanical,lengths of stay in the hospital between the two groups（P0.05）;Gram-negative bacilli was the main pathogens in the lower respiratory tract and subglottic secretion in the two groups.The dominant bacteria cultured in the two groups were pseudomonas aeruginosa and Baumanii.There was no significant difference between the two groups in the spectrum of bacteria（P0.05）;71.4% specimens bacteria culture in 35 cases of VAP in all patients was found the same dominant strains in the subglottic secretions and the lower air way respiratory tract secretions.Most gram-positive becteria,intestinal bacteria,normal flora of the cheek were found in five days after the subglottic.With a long time to reduce the concentration,but gradually increased the number of Pseudomonas aeruginosa,there was always a fungua.Conclusion The presence of subglottic secretion maybe an main origin of the pathogenetic organisms of VAP.SSD can reduced the incidence of VAP and delay time VAP occurs in patients with MV.The mortality rate,total MV time,ICU stay and hospital stay time were no significant effect.The dominant cultured bacteria in the lower airway secretion were gram-negative bacilli,most commonly Pseudomonas aeruginosa and Baumanii.