The impact of tracheal intubation on host defenses and risks for nosocomial pneumonia.

摘要: Nosocomial pneumonia remains a common complication in patients treated with endotracheal intubation and mechanical ventilation continues to have significant impact on the mortality rate of these patients. Epidemiologic studies shown that risk increases duration but period highest is first 2 weeks therapy. Gram-negative bacteria account for most nosocomial pneumonias intubated patients, Staphylococcus aureus may also play role what be polymicrobial infection. In seriously ill individuals, those long-term ventilation, Pseudomonas aeruginosa pathogen. Endotracheal predispose variety reasons (see Fig. 1). The tube can direct effects airway result reduction local host defenses. Thus, mucosal injury reduce mucociliary function, while upper defenses are bypassed effectiveness cough reduced. Indirectly, an enhanced capacity tracheobronchial cells bind gram-negative bacteria, effect favors colonization pneumonia. create binding sites basement membrane bronchial tree stimulation secretion mucus, which then stagnates potential bacterial adherence. enhances entry lung by serving as reservoir remain sequestered, safe from Respiratory therapy devices allow proliferate introduce them into patient if not handled properly. Finally, who enough require disease-associated impairments systemic defense, add caused use artificial airway. defense occur mechanically ventilated lead respiratory tract infection form either febrile tracheobronchitis or diagnosis difficult controversial. It made clinical criteria microbiologic criteria, latter using bronchoscopically directed protected specimen brush. Therapy always successful, antibiotics need supplemented topical antimicrobials. No clearly effective prophylactic strategy currently exists, our understanding pathogenesis has led some promising directions. As more data collected, inhaled antibiotics, selective digestive decontamination, enhancement cytokines pre-formed antibodies emerge useful approaches.