Efficacy of plasma procalcitonin in evaluating severity of community-acquired pneumonia in elderly patients / 中华老年医学杂志

ABSTRACT

Objective To analyze the plasma procalcitonin (PCT) as a predictor of the severity of community acquired pneumonia (CAP) in elderly patients.Methods Totally 90 elderly patients hospitalized with community acquired pneumonia from 2010 to 2011 were analyzed retrospectively for the relation between plasma procalcitonin and severity of pneumonia.All cases were divided into two groups,the severe group (n=36) and the non-severe group (n=54) according to diagnostic criteria.Results The level of plasma PCT was much lower in the severe group (median 2.44 μg/L) than that in the non-severe group (median 0.11 μg/L) (U=335.50,P=0.000).Among all patients,when PCT was lower than 0.5 μg/L,the incidence of non-severe CAP was 76％,however,when PCT was equal or above 2.0 μg/L,the incidence of non-severe CAP was reduced to 9％.In Binary logistic regression analysis,PCT was a risk factor of aged person with severe community acquired pneumonia independent of age and CRUB-65 scores [OR =1.328 (95 ％ confidential interval1.072,1.645)].PCT had a positive correlation with CRUB-65 scores (U=10.162,P=0.006).In all cases,the patients who improved well had lower PCT value than the remaining (median 0.21 μg/L,17.0μg/L; U=10.000,P=0.000),which also happened in severe cases (median 1.47 μg/L,17.0 μg/L;U=8.000,P=0.000).The area under the receiver operating characteristic curve was 0.872 (95％ confidential interval0.741,0.914).At a PCT cut-off level of greater than or equal to 2.0 μg/L,the sensitivity and specificity to predict the severity of aged person with CAP was 55.6％ and 98.9％ respectively.Conclusions Plasma PCT may be a good predictor to evaluate the severity of CAP in elderly patients.