A Prospective Study On The Clinical Characteristics Of Elderly Patients With Community Acquired Pneumonia And The Predictive Effectiveness Of Different Scoring Systems

Objective: We aimed to explore the characteristics of elderly community acquired pneumonia(CAP)and compare the performance of pneumonia severity index(PSI),CURB-65(confusion,urea nitrogen,respiratory rate,blood pressure and age ? 65 years),Chinese standardsfor the assessment of CAP(referred to as Chinese standards)and elderly community acquired pneumonia severity index(ECAPSI)to predict prognosis in elderly CAP.Methods : We collectedclinical data of CAP elderly patients from the Affiliated Hospital of Southwest Medical University from July 2015 to May 2016.The demographic characteristics,comorbidities,main symptoms and signs,laboratory results were included.The patients were divided into low risk group,middle risk group and high risk group according to the four scoring systems.We have taken the patients' death during hospitalization or 30 days after admission as the end point,to observe whether they were admitted to the ICU,whether mechanical ventilation was used,whether or not they have died,the length of stay,and whether or not returned to hospital within 30 days due to CAP if they havn't died during the last hospitalization.ICU admission rate,ratio of mechanical ventilation,length of hospital stay,mortality and readmission rate were compared among subgroups respectively.The efficacy of four scoring systems in predicting prognosis of elderly CAP was compared by drawing the ROC and calculating the AUC.Results:1.General information: A total of 344 patients were included in this study,of whom there were 241 males(70.1%)and 103 females(29.9%),aged from 65 to 97 years.There were 100 cases(29.1%)admitted to ICU,60 cases(15.4%)with mechanical ventilation,and 50 cases(14.5%)died within 30 days after admission.A total of 322 patients(93.6%)had at least one comorbidities,including 235 cases(68.3%)with COPD and 177 cases(51.5%)with cardiovascular diseases.There were 314 cases(91.3%)patients with cough,305 cases(88.7%)with expectoration,275 cases(79.9%)with dyspnea,239 cases(69.5%)with anorexia,72 cases(20.9%)with fever,and 35 cases(10.2%)with chest pain.Sputum culture was performed in 224 cases,of which 127 cases were cultured pathogenic bacteria,the positive rate was 56.7%.147 strains of pathogenic bacteria were cultured,of which there were 77 strains(52.3%)of fungi,64 strains(43.6%)of gram negative bacteria.The main fungi were Candida albicans(40.8%),gram negative bacteria were mainly including baumanii(16.3%),Klebsiella pneumoniae(7.5%),Pseudomonas aeruginosa(4.8%),Escherichia coli(4.1%).These major gram negative bacteria had high drug resistance and multiple drug resistance,especially baumanii.2.In each scoring system,serum albumin(ALB)level in non-high risk group was higher than that in high-risk group,while the level of procalcitonin(PCT),D-dimer,B type natriuretic peptide(BNP)was just the opposite.The correlation coefficients between them and PSI were:PCT0.602,ALB-0.388,D-dimer0.597,BNP0.538.The levels of PCT,D-dimer and BNP in the survival group were lower than those in the death group,while the ALB level was higher.3.Comparison of the efficacy of four scoring systems in and predicting prognosis: The ICU admission rate,ratio of mechanical ventilation,mortality and readmission rate were increased with the increase of risk level.The AUC of ECAPSI,PSI,CURB-65 and Chinese standards for predicting ICU admission were 0.820,0.840,0.704,0.664;for predicting mechanical ventilation were 0.824,0.840,0.718,0.718;and for predicting the death were 0.777,0.779,0.639,0.644.Conclusion:1.In this study,elderly CAP is often associated with the following characteristics: a variety of comorbidities,atypical symptoms and signs and high mortality.Many bacterial infections are gram negative bacteria of which bacterial resistance rate is high and multiple drug resistance is serious in elderly CAP.2.The levels of PCT,ALB,D-dimer and BNP are related to the severity of elderly CAP.3.In this study,these four kinds of scoring system could be used to predict the prognosis of elderly CAP in our hospital.The efficiency of predicting ICU admission is:PSI >ECAPSI >CURB-65>Chinese standard,predicting mechanical ventilation and death is PSI >ECAPSI> CURB-65.