持续声门下吸引预防呼吸机相关肺炎

Continuous aspiration of subglottic secretion for preventing ventUator-associated pneumonia

目的观察持续声门下吸引（CASS）预防机械通气（MV）患者发生呼吸机相关肺炎（VAP）的临床价值。方法将ICU 111例气管插管行MV的患者随机分为CASS吸引组56例为A组，对照组55例为B组，同步收集口咽部、声门下、下呼吸道分泌物进行细菌学检查。记录每日声门下分泌物的吸引量、发生VAP的例数及时间、MV天数、死亡人数。依据保护性毛刷采样定量培养结果确定VAP病原体。结果（1）MV5d内，A组VAP发生率10．7％显著低于B组的41．8％（P〈0．01）；A组VAP发生的中位时间6．0d，四分位间距1．5d，显著较B组中位时间4．0d，四分位间距3．0d为晚（P〈0．05）；A组声门下分泌物革兰氏阳性G^＋致病菌浓度明显低于B组（P〈0．01）。（2）28例（47．5％）患者下呼吸道分泌物出现致病菌前声门下分泌物就发现了该致病菌；21例（44．7％）口咽部、声门下、下呼吸道分泌物分离出来的致病菌是一致的。（2）两组下呼吸道分泌物致病菌分布以革兰氏阴性G-杆菌为主，主要优势菌为铜绿假单胞菌和肺炎克雷伯氏菌。（4）未发生VAP者声门下分泌物的平均吸引量显著高于发生VAP者吸引量（P〈0．01），每日吸引量较多患者发生VAP时间迟于较少患者（P〈0．05），MV时间短于较少患者（P〈0．01）。结论（1）CASS可以降低早发VAP的发生率，使发生时间延迟，声门下分泌物的G^＋致病菌浓度降低。（2）声门下分泌物是VAP病原菌的重要来源。（3）声门下分泌物吸引量与是否发生VAP及VAP发生时间有关。（4）CASS方法安全简便，并发症少。

[ Abstract] Objective To study the clinical effects of continuous aspiration of subglottic secretion （CASS） on ventilator-associated pneumonia （VAP） in mechanically ventilated （MV） patients. Method All intubated patients, who received MV, were randomly divided into two groups： patients receiving CASS （group A） and patients not receiving CASS as control group （group B）. Scraping-pharynx specimen, the subglottic secretion, and the secretion from lower airway were collected at the same time for quantitative bacterial culture and antibiotic sensitivity test. Daily volume of subglottie secretions, number of YAP patients, the specific time of occurrence of VAP, days of ventilation, and number of deaths were recorded. Etiologic diagnosis of VAP was based on the quantitative bacterial culture of secretion by protectire specimen brush （PSB）. Results （1） In patients with MV ~ ~5 days, the incidence of VAP was 10.7% in group A, much lower than those in group B （41.8%, P 〈 0.01）. The onset of VAP was delayed in group A as compared with group B （ P 〈 0.05）. The number of G~ bacteria colony in subglottic secretion from group A was decreased significantly compared to that of group B （ P 〈 0.01）. （2） The same organism as found in previously subglottic secretion was isolated by PSB in 28 （47.5%） patients. In 21 （44.7%） patients the same organism was found in scraping-pharynx specimen, the subglottic secretion,and the lower airway secretion.（3）Gram-negative bacilli were the main pathogens in the lower respiratory tract in bothgroups.The dominant bacteria were Pseudomones aerugionosa and Klebsielia pneumoniae,（4）Volume of subglottic secretions in patients with non-VAP was higher than those with VAP（P〈0.01）.The onsets of VAP in aspiration group with higher volumce of secretion aspirated out was delayed as compared with aspiration group with less amoure of secrection drained（P〈0.05）,and in turn the duration of ventilation were shortened（P〈0.01）.Conclusions （1）CASS reduced the incidence of VAP in patients with MV〈5 days,The onset of VAP was delayed in group A as compared with group B.The number of G^＋ bacteria colony in the subglottic secretion was reduced by CASS.（2） The presence of subglottic secretion may be an origin of the pathogenetic organisms of VAP.（3）The volume of subglottic secretion was inversely related to the incidence of VAP and the onset time of VAP.（4） CASS may be a simple,safe,and effective approsch nearly without complications to prevention of VAP.