The Diagnostic Value Of Serum Procalcitonin In The Elderly Patients With Community Acquired Pneumonia

ObjectiveTo compare the usefulness of procalcitonin(PCT) in detecting infection in elderlypatients with that of other clinical and biological markers.MethodsThis study covers346CAP cases admitted to Shanghai Jiaotong University attached6thHospital between July2013and January2014. Patients were divided into two groups(＞60years, n=178;≤60years, n=168) and were measured for procalcitonin, C-reactiveprotein (CRP), white blood cell, fever，respiratory rate, blood pressure and microbiologicstudies.ResultsBlood cultures were positive in67individuals (37.6%) in elderly patients and69individuals (41.0%) in adult patients.The levels of procalcitonin were significant higher ininfection compared with uninfection (elderly:0.862vs0.068,P＜0.05; adult:3.36vs0.068,P＜0.01),and the levels of procalcitonin were significant higher in adult CAP comparedwith elderly CAP(P＜0.01). The area under the curve for predicting mortality was highestfor the PCT (0.636;95%CI:0.534-0.737), followed by the area under the curve for WBCC(0.629;95%CI:0.533-0.724) and C-reactive protein (0.582;95%CI:0.494-0.671). TheAUC-ROC for PCT to predict CAP in elderly was0.942and, considering acut-off value≥0.101ng/ml,sensitivity was85.4%and specificity was97%. The AUC-ROCfor PCT to predict CAP in very elderly was0.849and, considering a cut-off value≥0.0975ng/ml, sensitivity was73.1%and specificity was93%.ConclusionsThe levels of procalcitonin are more useful than the levels of CRP or WBCC topredict the CAP in elderly.The PCT levels depend on the severity of pneumonia.