Respir Care. 1994 Dec;39(12):1191-236.
Pneumonia is the second most common nosocomial infection in the United States and is associated with substantial morbidity and mortality. Most patients with nosocomial pneumonia are those with extremes of age, severe underlying disease, immunosuppression, depressed sensorium, and cardiopulmonary disease, and those who have had thoracoabdominal surgery. Although patients with mechanically assisted ventilation do not comprise a major proportion of patients with nosocomial pneumonia, they have the highest risk of developing the infection. Most bacterial nosocomial pneumonias occur by aspiration of bacteria colonizing the oropharynx or upper gastrointestinal tract of the patient. Intubation and mechanical ventilation greatly increase the risk of nosocomial bacterial pneumonia because they alter first-line patient defenses. Pneumonias due to Legionella spp., Aspergillus spp., and influenza virus are often caused by inhalation of contaminated aerosols. Respiratory syncytial virus (RSV) infection usually follows viral inoculation of the conjunctivae or nasal mucosa by contaminated hands. Traditional preventive measures for nosocomial pneumonia include decreasing aspiration by the patient, preventing cross-contamination or colonization via hands of personnel, appropriate disinfection or sterilization or respiratory therapy devices, use of available vaccines to protect against particular infections, and education of hospital staff and patients. New measures under investigation involve reducing oropharyngeal and gastric colonization by pathogenic microorganisms.
肺炎是美国第二常见的医院感染，与较高的发病率和死亡率相关。大多数医院获得性肺炎患者是年龄极大或极小者、患有严重基础疾病者、免疫抑制者、意识障碍者、心肺疾病患者以及接受过胸腹手术者。虽然机械辅助通气患者在医院获得性肺炎患者中所占比例不大，但他们发生感染的风险最高。大多数细菌性医院获得性肺炎是由患者口咽部或上消化道定植菌的误吸引起的。插管和机械通气会极大增加医院获得性细菌性肺炎的风险，因为它们会改变患者的一线防御机制。由军团菌属、曲霉属和流感病毒引起的肺炎通常是由吸入受污染的气溶胶所致。呼吸道合胞病毒（RSV）感染通常是通过被污染的手将病毒接种到结膜或鼻黏膜而引起的。医院获得性肺炎的传统预防措施包括减少患者误吸、防止人员手部交叉污染或定植、对呼吸治疗设备进行适当消毒或灭菌、使用现有疫苗预防特定感染以及对医院工作人员和患者进行教育。正在研究的新措施包括减少致病微生物在口咽部和胃内的定植。
