George D L
Baptist Memorial Hospital, Memphis, Tennessee, USA.
Clin Chest Med. 1995 Mar;16(1):29-44.
Pneumonia is the most commonly reported nosocomial infection in ICU patients, occurring predominantly in patients whose lungs are ventilated, at a rate of 1% to 3% per day of mechanical ventilation. Substantially increased costs and mortality have been attributed to nosocomial pneumonia. Our understanding of the epidemiology of nosocomial pneumonia in ICU populations has been limited by the reliance of most published studies on clinical diagnostic criteria, which are nonspecific. In addition to mechanical ventilation and tracheal intubation, other suspected risk factors of importance include chronic lung disease, age, severity of illness, upper abdominal or thoracic surgery, head trauma or depressed level of consciousness, and gastric acid inhibition. Aspiration appears to be the primary mode of inoculation of microorganisms into the distal lung; however, the relative importance of different sites as reservoirs for aspiration is controversial. It is hoped that studies based on improved diagnostic techniques, such as quantitative cultures of protected brush or bronchoalveolar lavage specimens, will provide the basis for an improved understanding of the epidemiology and prevention of this important infection in critically ill patients.
肺炎是重症监护病房（ICU）患者中最常报告的医院感染，主要发生在接受机械通气的患者中，机械通气每天的发生率为1%至3%。医院获得性肺炎导致成本大幅增加和死亡率上升。由于大多数已发表的研究依赖非特异性的临床诊断标准，我们对ICU患者医院获得性肺炎流行病学的了解受到了限制。除了机械通气和气管插管外，其他重要的可疑危险因素包括慢性肺病、年龄、疾病严重程度、上腹部或胸部手术、头部创伤或意识水平降低以及胃酸抑制。误吸似乎是微生物进入远端肺部的主要接种方式；然而，不同部位作为误吸源的相对重要性存在争议。希望基于改进诊断技术（如保护性毛刷或支气管肺泡灌洗标本的定量培养）的研究，将为更好地理解危重症患者中这种重要感染的流行病学和预防提供依据。
