细菌是慢阻肺急性加重的主要原因。有证据显示脓性痰多和下呼吸道细菌感染相关。[58]Soler N, Agusti C, Angrill J, et al. Bronchoscopic validation of the significance of sputum purulence in severe exacerbations of chronic obstructive pulmonary disease. Thorax. 2007;62:29-35.http://www.ncbi.nlm.nih.gov/pubmed/16928715?tool=bestpractice.com 由于慢阻肺患者的下呼吸道不是无菌的,上、下呼吸道标本培养结果的解读必须慎重。慢阻肺急性加重患者细菌菌落数是否超出基线水平目前证据不确定。[59]Wilkinson TM, Hurst JR, Perera WR, et al. Effect of interactions between lower airway bacterial and rhinoviral infection in exacerbations of COPD. Chest. 2006;129:317-324.http://www.ncbi.nlm.nih.gov/pubmed/16478847?tool=bestpractice.com[60]Sethi S, Sethi R, Eschberger K, et al. Airway bacterial concentrations and exacerbations of chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 2007;176:356-361.http://www.ncbi.nlm.nih.gov/pubmed/17478618?tool=bestpractice.com
最常被识别出的细菌病原体包括流感嗜血杆菌、肺炎链球菌和卡他莫拉菌。[31]Woodhead M, Blasi F, Ewig S, et al. Guidelines for the management of adult lower respiratory tract infections - full version. Clini Microbiol Infect. 2011;17(suppl 6):E1-E59.http://onlinelibrary.wiley.com/doi/10.1111/j.1469-0691.2011.03672.x/fullhttp://www.ncbi.nlm.nih.gov/pubmed/21951385?tool=bestpractice.com[51]Wedzicha JA, Seemungal TA. COPD exacerbations: defining their cause and prevention. Lancet. 2007;370:786-796.http://www.ncbi.nlm.nih.gov/pubmed/17765528?tool=bestpractice.com 其他革兰氏阳性菌(例如金黄色葡萄球菌)和革兰氏阴性菌(例如铜绿假单胞菌)在 COPD 急性加重发病机制中的作用还不明确,但 COPD 更严重且加重更频繁和/或更严重的患者,或近期住院或近期(2 周内)每日全身性应用皮质类固醇(即泼尼松龙>10 mg/天)的患者更容易出现这些致病菌定植。[31]Woodhead M, Blasi F, Ewig S, et al. Guidelines for the management of adult lower respiratory tract infections - full version. Clini Microbiol Infect. 2011;17(suppl 6):E1-E59.http://onlinelibrary.wiley.com/doi/10.1111/j.1469-0691.2011.03672.x/fullhttp://www.ncbi.nlm.nih.gov/pubmed/21951385?tool=bestpractice.com[61]Caramori G, Adcock IM, Papi A. Clinical definition of COPD exacerbations and classification of their severity. South Med J. 2009;102:277-282.http://www.ncbi.nlm.nih.gov/pubmed/19204646?tool=bestpractice.com
值得注意的是,有证据显示慢阻肺患者感染新的细菌菌株是急性加重的危险因素。[62]Sethi S, Evans N, Grant BJ, et al. New strains of bacteria and exacerbations of chronic obstructive pulmonary disease. N Engl J Med. 2002;347:465-471.http://www.ncbi.nlm.nih.gov/pubmed/12181400?tool=bestpractice.com 先天和/或适应性免疫反应的改变可能导致炎症和感染循环性持续存在。[42]Sethi S, Murphy TF. Infection in the pathogenesis and course of chronic obstructive pulmonary disease. N Engl J Med. 2008;359:2355-2365.http://www.ncbi.nlm.nih.gov/pubmed/19038881?tool=bestpractice.com
细菌和病毒性呼吸道致病菌的混合感染和更加严重的急性发作相关。[50]Papi A, Bellettato CM, Braccioni F, et al. Infections and airway inflammation in chronic obstructive pulmonary disease severe exacerbations. Am J Respir Crit Care Med. 2006;173:1114-1121.http://www.ncbi.nlm.nih.gov/pubmed/16484677?tool=bestpractice.com 对中到重度急性加重的患者应用抗菌药物治疗和预后改善相关。[63]Anthonisen NR, Manfreda J, Warren CP, et al. Antibiotic therapy in exacerbations of chronic obstructive pulmonary disease. Ann Intern Med. 1987;106:196-204.http://www.ncbi.nlm.nih.gov/pubmed/3492164?tool=bestpractice.com[64]Puhan MA, Vollenweider D, Latshang T, et al. Exacerbations of chronic obstructive pulmonary disease: when are antibiotics indicated? A systematic review. Respir Res. 2007;8:30.http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17407610http://www.ncbi.nlm.nih.gov/pubmed/17407610?tool=bestpractice.com 流感疫苗接种可能在降低铜绿假单胞菌感染风险方面具有保护作用。[31]Woodhead M, Blasi F, Ewig S, et al. Guidelines for the management of adult lower respiratory tract infections - full version. Clini Microbiol Infect. 2011;17(suppl 6):E1-E59.http://onlinelibrary.wiley.com/doi/10.1111/j.1469-0691.2011.03672.x/fullhttp://www.ncbi.nlm.nih.gov/pubmed/21951385?tool=bestpractice.com