Servei de Pneumologia, Institut del Tòrax, Hospital Clinic, IDIBAPS, Universitat de Barcelona, Barcelona 08036, Spain.
Thorax. 2011 Apr;66(4):340-6. doi: 10.1136/thx.2010.143982. Epub 2011 Jan 21.
The distribution of the microbial aetiology and mortality of community-acquired pneumonia (CAP) was investigated in relation to the clinical setting and severity scores (pneumonia severity index (PSI) and confusion, blood urea nitrogen, respiratory rate, blood pressure, age (CURB-65)).
3523 patients with CAP were included (15% outpatients, 85% inpatients). The distribution of the microbial aetiology in relation to the clinical setting and severity scores (PSI, CURB-65) and the relative mortality of different aetiologies across the severity scores were analysed.
The aetiology was established in 1463 patients (42%), of whom 257 died (7%). The ranking of aetiologies varied according to site of care, with increasing frequency of Streptococcus pneumoniae and mixed aetiologies and decreasing frequency of atypical pathogens in hospitalised patients and those in ICUs. The distribution of aetiologies according to severity scores showed corresponding patterns; however, the severity scores were more sensitive to Gram-negative enteric bacilli (GNEB) and Pseudomonas aeruginosa and less sensitive in identifying mixed aetiologies as moderate- and high-risk conditions. Mortality rates according to aetiology and severity scoring showed increasing mortality rates for all pathogens except atypical pathogens. S pneumoniae had the highest number of deaths while GNEB, P aeruginosa, Staphylococcus aureus and mixed aetiologies had the highest mortality rates. Legionella pneumophila was similarly distributed according to site of care and prognostic scores.
CAP due to atypical bacterial pathogens is recognised both clinically and by severity scoring as a low-risk condition. Severity scores are more sensitive in identifying patients with GNEB and P aeruginosa as moderate- and high-risk aetiologies whereas mixed aetiologies may be underestimated.
本研究旨在探讨社区获得性肺炎（CAP）的微生物病因学和死亡率分布与临床环境和严重程度评分（肺炎严重指数（PSI）和意识障碍、血尿素氮、呼吸频率、血压、年龄（CURB-65））的关系。
共纳入 3523 例 CAP 患者（15%为门诊患者，85%为住院患者）。分析了微生物病因与临床环境和严重程度评分（PSI、CURB-65）的关系，以及不同病因在不同严重程度评分中的相对死亡率。
在 1463 例（42%）患者中确定了病因，其中 257 例死亡（7%）。病因的分布因治疗场所而异，住院患者和 ICU 患者中肺炎链球菌和混合病因的发生率增加，而非典型病原体的发生率降低。根据严重程度评分的病因分布也呈现出相应的模式；然而，严重程度评分对革兰氏阴性肠杆菌和铜绿假单胞菌更为敏感，而对识别中度和高度风险的混合病因则不太敏感。根据病因和严重程度评分的死亡率显示，除非典型病原体外，所有病原体的死亡率均呈上升趋势。肺炎链球菌导致的死亡人数最多，而革兰氏阴性肠杆菌、铜绿假单胞菌、金黄色葡萄球菌和混合病因的死亡率最高。嗜肺军团菌的分布也与治疗场所和预后评分有关。
除非典型细菌病原体外，临床和严重程度评分均认为 CAP 为低危疾病。严重程度评分更能识别出革兰氏阴性肠杆菌和铜绿假单胞菌为中度和高度风险的病因，而混合病因可能被低估。
