预后由三大主要因素决定:患者年龄、总体健康状况(是否存在并发症)以及进行抗生素治疗的地点。一般而言,门诊患者的死亡率<1%,住院患者的死亡率则介于 5% 至 15% 之间,但对于需要收住 ICU 的患者,死亡率则上升到 20% 至 50% 之间。[5]Torres A, Peetermans WE, Viegi G, et al. Risk factors for community-acquired pneumonia in adults in Europe: a literature review. Thorax. 2013 Nov;68(11):1057-65.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3812874/http://www.ncbi.nlm.nih.gov/pubmed/24130229?tool=bestpractice.com[133]Luna HI, Pankey G. The utility of blood culture in patients with community-acquired pneumonia. Ochsner J. 2001 Apr;3(2):85-93.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3116772/http://www.ncbi.nlm.nih.gov/pubmed/21765724?tool=bestpractice.com
一些危险因素,例如菌血症、收入 ICU 治疗、共病(尤其是神经系统疾病)以及可能存在多重耐药病原体(例如金黄色葡萄球菌、铜绿假单胞菌、肠杆菌)可导致 30 天死亡率升高。[35]Cillóniz C, Polverino E, Ewig S, et al. Impact of age and comorbidity on cause and outcome in community-acquired pneumonia. Chest. 2013 Sep;144(3):999-1007.http://www.ncbi.nlm.nih.gov/pubmed/23670047?tool=bestpractice.com[134]Torres A, Cillóniz C, Ferrer M, et al. Bacteraemia and antibiotic-resistant pathogens in community acquired pneumonia: risk and prognosis. Eur Respir J. 2015 May;45(5):1353-63.http://www.ncbi.nlm.nih.gov/pubmed/25614173?tool=bestpractice.com[135]Sligl WI, Marrie TJ. Severe community-acquired pneumonia. Crit Care Clin. 2013 Jul;29(3):563-601.http://www.ncbi.nlm.nih.gov/pubmed/23830654?tool=bestpractice.com[136]Melzer M, Welch C. 30-day mortality in UK patients with bacteraemic community-acquired pneumonia. Infection. 2013 Oct;41(5):1005-11.http://www.ncbi.nlm.nih.gov/pubmed/23703286?tool=bestpractice.com
CAP 患者再次入院率介于 7% 至 12% 之间。[137]Jasti H, Mortensen EM, Obrosky DS, et al. Causes and risk factors for rehospitalization of patients hospitalized with community-acquired pneumonia. Clin Infect Dis. 2008 Feb 15;46(4):550-6.http://cid.oxfordjournals.org/content/46/4/550.fullhttp://www.ncbi.nlm.nih.gov/pubmed/18194099?tool=bestpractice.com[138]Capelastegui A, España Yandiola PP, Quintana JM, et al. Predictors of short-term rehospitalization following discharge of patients hospitalized with community-acquired pneumonia. Chest. 2009 Oct;136(4):1079-85.http://www.ncbi.nlm.nih.gov/pubmed/19395580?tool=bestpractice.com 在大多数情况下,再次入院的原因都是共病急性加重(主要为心血管疾病、肺部疾病或神经系统疾病)。
正在研究作为死亡率预测指标的预后生物标志物,例如前肾上腺髓质素、激素原形式的心房利尿钠肽、皮质醇、原降钙素和 C 反应蛋白;但在临床实践中将这些生物标志物用于此功能之前,仍需要进一步的研究。[139]Viasus D, Del Rio-Pertuz G, Simonetti AF, et al. Biomarkers for predicting short-term mortality in community-acquired pneumonia: a systematic review and meta-analysis. J Infect. 2016 Mar;72(3):273-82.http://www.ncbi.nlm.nih.gov/pubmed/26777314?tool=bestpractice.com