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 interval:1.072,1.645)].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 interval:0.741,0.914).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.

OBJECTIVE To assess the correlation between the steady-state minimal concentration （cmin） and 24 h area under the drug concentration-time curve （AUC24）/minimal inhibitory concentration （MIC） ratio （AUC24/MIC） of vancomycin in pediatric patients， and analyze independent risk factors for treatment failure. METHODS Data of hospitalized children treated with vancomycin and receiving therapeutic drug monitoring in our hospital from January 2021 to July 2024 were retrospectively collected and divided into success group and failure group according to whether the treatment was successful or not. Spearman correlation analysis was used to analyze the correlation between cmin and AUC24/MIC of vancomycin， and one-way and multifactorial Logistic regression analyses were used to screen the independent risk factors for vancomycin treatment failure. RESULTS A total of 59 children were included， with 41 in the success group and 18 in the failure group. Compared with the failure group， AUC24/MIC of vancomycin was significantly higher in the success group （P＝0.038）， but there was no statistically significant difference in the cmin of the two groups （P＞0.05）； cmin of vancomycin was significantly positively correlated with AUC24/MIC （r＝0.499， P＜0.001）， but it has a certain efficacy in predicting the achievement of the AUC24/MIC standard （≥400） （area under the receiver operator characteristic curve＝0.696）， with an optimal cutoff value of 6.05 mg/L determined by the Youden index. The efficacy of AUC24/ MIC in predicting treatment failure was superior to cmin （areas under the receiver operator characteristic curve were 0.671 vs. 0.523， P were 0.038 vs. 0.684）， with higher sensitivity （83.3% vs. 66.7%）. Hypoproteinemia and AUC24/MIC≤369.1 were independent risk factors for vancomycin treatment failure （P＜0.05）. The incidence of nephrotoxicity was 3.4%. CONCLUSIONS There is a significant positive correlation between cmin and AUC24/MIC of vancomycin in pediatric patients； hypoproteinemia and AUC24/MIC≤369.1 are independent risk factors for vancomycin treatment failure in children.