Anesthesia and Critical Care Department, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Minerva Anestesiol. 2011 Mar;77(3):323-33. Epub 2010 Dec 9.
Ventilator-associated pneumonia (VAP), which develops in patients receiving mechanical ventilation, is the most common nosocomial infection in patients with acute respiratory failure. The major mechanism of lower respiratory tract colonization is aspiration of bacteria-colonized secretions from the oropharynx into the lower airways. The hydrostatic pressure of the secretions that collect in the subglottic space, which is the area above the endotracheal tube (ETT) cuff, or aerosolization of bacteria from the secretions collected within the respiratory tubing may facilitate the leakage into the lower airways. Ideally, the elimination of the mechanisms responsible for aspiration would decrease the incidence of VAP. Several preventive measures have been tested in clinical trials with little success.Here we present the results of our efforts to develop novel approaches for the prevention of VAP. Specifically, we found that keeping ventilated patients in a lateral position, which eliminates gravitational forces, is feasible and possibly advantageous. Additionally, several novel medical devices have been recently developed to prevent bacterial biofilm formation from the ETT and breathing tubing. These devices include coated ETTs, mucus shavers and mucus slurpers. Prevention of ETT bacterial colonization showed decreased bacterial colonization of the respiratory circuit and of the lower respiratory tract in laboratory studies and clinical trials. Future large studies should be designed to test the hypothesis that VAP can be prevented with these novel strategies. While there is a current focus on the use of respiratory devices to prevent biofilm formation and microaspiration, it is important to remember that lower respiratory tract colonization is multifactorial. Prevention of VAP cannot be achieved solely by eliminating bacterial biofilm on respiratory devices, and more comprehensive care of the intubated patient needs to be implemented.
呼吸机相关性肺炎（VAP）是指在接受机械通气的患者中发生的肺炎，是急性呼吸衰竭患者中最常见的医院获得性感染。下呼吸道定植的主要机制是将口咽定植的分泌物吸入下呼吸道。积聚在声门下区域（气管内管（ETT）套囊上方的区域）的分泌物的静水压力，或从呼吸管内收集的分泌物中的细菌气溶胶化，可能有助于分泌物渗漏到下呼吸道。理想情况下，消除导致吸入的机制会降低 VAP 的发生率。已经在临床试验中测试了几种预防措施，但收效甚微。在这里，我们介绍了我们为开发预防 VAP 的新方法所做的努力的结果。具体来说，我们发现让接受通气的患者保持侧卧体位，消除重力作用，是可行的，并且可能是有利的。此外，最近还开发了几种新型医疗设备，以防止 ETT 和呼吸管中的细菌生物膜形成。这些设备包括涂层 ETT、黏液刮刀和黏液抽吸器。预防 ETT 细菌定植的研究表明，在实验室研究和临床试验中，呼吸道回路和下呼吸道的细菌定植减少。应设计未来的大型研究来检验这样一个假设，即这些新策略可以预防 VAP。虽然目前的重点是使用呼吸设备来防止生物膜形成和微吸入，但重要的是要记住，下呼吸道定植是多因素的。预防 VAP 不能仅通过消除呼吸设备上的细菌生物膜来实现，需要对插管患者进行更全面的护理。
