Clinical Aspects And Prognostic Factors Of Severe Community-acquired Pneumonia

Backgroud：Severe community-acquired pneumonia (SCAP) is one of the commondiseases that threat human healthy, which once been known as the "master of humandeaths”. Both of its prevalence and mortality increased year by year worldwide. Onone hand, due to an aging population, combined with chronic underlying diseases leadto high risk of infection in the host; on the other hand, the changes of pathogensconstitute a spectrum, and the rapid development of pathogen resistance,whichincrease the difficulty of SCAP Clinical diagnosis and treatment. At the same time, onthe definition, diagnosis, treatment, and many other issues, SCAP is still controversial.Objective：To analyse and conclude the etiology and characteristics of the SCAP,conducive to understand the SCAP pathogens, the corresponding drug susceptibilityand prognostic factors, providing the basis for the diagnosis and treatment of SCAP.Methods：Use the design method of descriptive study. By collecting the diagnosedcases of community-acquired pneumonia (aged>15) by Guangzhou First MunicipalPeople’s Hospital in seven years from July2004to July2011,using the Chinesecommunity-acquired pneumonia diagnosis and treatment guidelines (2006) fordiagnosis and definition of community-acquired pneumonia and using the diagnosticcriteria of the2007Infectious Diseases Society/American Thoracic Society (IDSA/ATS) issued jointly by the adult CAP treatment guidelines on SCAP,there were134 episodes included. Based on the outcomes, the patients in each subgroup were dividedinto the death group and survival group. Date recorded included patient demographics,comorbidities, antimicrobial treatment, investigations and outcome (mortality, lengthof stay). Use logistic regression methods, screen and analyse of the SCAP prognosticfactors.Results：During seven years from July2004to July2011, the medical records ofconsecutive patients aged>15years with diagnosis of pneumonia in the GuangzhouFirst Municipal People’s Hospital were1610episodes,in which134episodes(admission CAP8.3%)were enrolled in the study. The mean patient’s average ageswere59±19years (24to92years), in which55episodes died, mortality rate was41%.A microbiological diagnosis was made in25%of episodes.The most frequentcausative organisms were Streptococcus pneumoniae (9%), Haemophilus influenzae(5%), Staphylococcus aureus (4%). Blood cultures were positive in8.2%.82episodes(61%) required mechanical ventilation and30patients (22%) required inotropicsupport. There were four factors associated with mortality on multivariate analysis.Three risk factors followed by OR values were septic shock, confusion/disorientation,acute renal failure, Non-invasive ventilation for protective factors.Conclusions：Despite appropriate antimicrobial therapy and supportive treatment,SCAP was associated with a mortality rate of41%.Only25%of the SCAP patientswere made microbiological diagnosis, The most common pathogen wereStreptococcus pneumoniae and Haemophilus influenzae. the IDSA/ATS predictionrule for defining severe CAP is poorly predicted by the CURB65scores, CURB65scores was not suite for defining severe CAP.Septic shock, confusion/disorientation,and acute renal failure were SCAP prognostic risk factors. Non-invasive ventilationwas a protective factor.