The clinical application of procalcitonin, leukocyte count and C-reactive protein in elderly patients with infection / 中华老年医学杂志

ABSTRACT

Objective To analyze and compare the clinical application values of procalcitonin (PCT),leukocyte count (WBC) and C-reactive protein(CRP) in elder patients with infection.Methods In patients(age≥ 65 yrs,axillary temperature ＞38.0℃)with infection or suspected infection,PCT,WBC,CRP and other bacteriological examination were performed.The electronic medical records from the HIS system of our hospital were analyzed retrospectively in combination with medical history.Results Of the enrolled 219 patients,65 ones were in control group,48 ones SIRS,51 ones sepsis and 55 ones MODS.There was a positive correlation between the level of serum PCT and the infection degree.The Spearman correlation coefficient was 0.706 (95％CI0.616-0.797,P=0.000).Based on the highest Youden index (sensitivity+specificity-1),the best cutoff point of diagnosis for PCT was ＞0.341 μg/L (sensitivity 84.5％,specificity 55.8％),a analysis of receiver operating characteristic(ROC) curve about PCT,WBC and CRP was carried.Area under the curve (AUC) of PCT to controlled infection was 0.916 (95％CI0.864-0.967,P=0.000).Based on the highest Youden index (sensitivity+ specificity-1),the judging threshold of PCT to infection controlled or not was 0.73 μg/L (sensitivity 84.6％,specificity 88.0％).PCT level after treatment ＞0.73 μg/L showed the uncontrolled infection,＜ 0.73 μg/L controlled.Conclusions PCT has a higher specificity for elder patients with infection.The variation of PCT level can guide the application of antibiotics,avoid abuse and decrease the occurrence of drug-resistant bacteria.