The Diagnostic Value Of Procalcitonin In Bacterial Infectious Diseases

Objective:To retrospectively analyze the level of procalcitonin(PCT)in patients in our hospital,to explore its diagnostic value in bacterial infectious diseases,and to analyze the differences between different local infections and the severity of the disease.Relevance provides a basis for clinical diagnosis.Methods:Recalling that 5,111 patients were admitted to the Second Affiliated Hospital of Nanchang University from June 2017 to December 2017,and PCT examinations were performed,excluding patients with unclear diagnosis,incomplete case data,and failure to meet the inclusion criteria,and there were 1299 remaining cases.Whether to incorporate bacterial infection will be divided into infection group 837 cases(328cases of pulmonary infection,143 cases of urinary tract infection,109 cases of hepatic infection,59 cases of biliary system infection,30 cases of bloodstream infection,other parts such as traumatic infection,A total of 168 cases of nervous system infections,abdominal abscesses,etc.;462 cases of non-infected groups(including cardiac insufficiency,coronary heart disease,acute pancreatitis,interstitial lung disease,tumors,etc.).All patients received venous blood for PCT,CRP,and WBC tests at the time of admission.The following analysis is performed by statistical methods:1.According to the measured results,the sensitivity,specificity of PCT,CRP and WBC in infectious diseases were analyzed with PCT ? 0.5 ng/mL,CRP ? 8 mg/L,and WBC ? 9.5 × 109/L as positive thresholds.Positive predictive value,negative predictive value,Youden index,and the results of the joint detection of PCT,WBC,and CRP;2.Analyze and compare the sensitivity of PCT,CRP,and WBC in different infection sites and whether there is statistical difference;3.Compare the mean values of PCT and CRP at different sites of infection anduse the mean plus or minus standard deviation to see if there is statistical significance;4.Analyze whether there is a correlation between PCT levels and the severity of the disease.Results:1.The sensitivity,specificity,positive predictive value,negative predictive value and yoden index of PCT,CRP and WBC in the diagnosis of infectious diseases were:PCT(sensitivity 75.98%,specificity 82.03%,positive predictive value 72.86%,negative predictive value)62.66%,Yoden index 0.58);CRP(sensitivity 86.26%,specificity 58.23%,positive predictive value 72.86%,negative predictive value62.66%,norden index 0.44);WBC(sensitivity 80.17%,specificity 68.42% Positive predictive value was 82.13%,negative was 65.56%,and norden index was 0.49),among which PCT specificity was the highest,and the difference was statistically significant(P<0.05).The highest sensitivity of CRP was statistically significant(P<0.05).Sensitivity and specificity of PCT,CRP,and WBC were combined.The sensitivity of PCT+CRP was 92.3% and specificity was 82.03%;the sensitivity of PCT+WBC was 86.3% and specificity was 84.5%;the sensitivity of CRP+WBC was94.8%.(78.5% specificity).The positive rate of PCT in non-infectious diseases was30.95%.Compared with infectious diseases,P<0.05 difference was statistically significant.2.PCT levels in different sites were compared: bloodstream infections(9.55±6.32)ng/ml,urinary tract infections(4.71±5.96)ng/ml,lung infections(4.24±5.46)ng/ml,and biliary system sensations(3.7±2.35)Ng/ml,severe hepatitis infection(3.08±4.81)ng/ml,CRP level: severe hepatitis infection group(57.2±13.6)mg/L,urinary tract infection group(48.8±25.1)mg/L,biliary system Infection(38.9±18.16)mg/L,lung infection group(32.5±14.78)mg/L.The levels of PCT and CRP in the bloodstream infection group were higher than those in other sites.Analysis of variance(ANOVA)P<0.05 showed significant difference between groups.The levels of PCT and CRP in other parts of the infection were not statistically significant(P>0.05).the difference was not statistically significant.3.In lung infections {community-acquired pneumonia,hospital-acquired pneumonia(including ventilator-associated pneumonia)} positive rates of PCT,CRP,WBC in the CAP group were(PCT: 70.89%,CRP: 86.08%,WBC: 85.54 %);HAP group(PCT: 79.12%,CRP: 93.4%,WBC: 89.01%).The positive rate of CRP in HAP group was significantly higher than that in CAP group(P<0.05).The positive rates of WBC and PCT were not different in CAP group and HAP group.The PCT level was severe pneumonia(9.80±14.44)ng/ml> non-severe pneumonia(3.38±3.66)ng/ml.P<0.05,the difference was statistically significant.4.In urinary tract infections,PCT levels,upper urinary tract infection(6.72±4.69)ng/ml> lower urinary tract sensation(2.82±1.74)ng/ml.P<0.05,the difference was statistically significant.The positive rate of PCT in upper urinary tract infection was83.7%,which was significantly higher than that of lower urinary tract infection71.43%(P<0.05).The difference was statistically significant.5.The PCT level of severe hepatitis infection group(3.08±4.81)ng/ml> PCT level of severe hepatitis without infection(0.72±0.62)ng/ml,P<0.05,the difference was statistically significant.The positive rate of PCT in severe hepatitis infection group was significantly higher than that of non-coinfection group(3),76.15%,P<0.05,and the difference was statistically significant.6.The positive rate of gram-negative bacteria(G-)PCT in blood culture was81.82% was significantly higher than that of gram-positive bacteria(G+)73.68%,P<0.05,the difference was statistically significant;the level of gram-negative bacteria PCT was 0.9ng/ml--->100ng/ml,gram-positive bacteria PCT level was0.07ng/ml---32.9ng/ml.Conclusion:1.The sensitivity of CRP in infectious diseases was significantly higher than that of PCT and WBC;the specificity of PCT was higher than that of CRP and WBC;PCT combined with CRP and WBC could significantly increase the sensitivity and specificity of diagnosis,and had certain value for clinical identification of bacterial infection.2.The levels of PCT and CRP in the bloodstream were significantly higher than those in other sites,and there was no significant difference between other sites of infection.The level of serum procalcitonin has a certain guiding role in the severity of the disease and the positioning(such as the distinction between upper urinary tractand lower urinary tract infection).Higher PCT levels often indicate that the infection is heavier and should attract the attention of clinicians.3.In the bloodstream infection,the PCT level and positive rate of gram-negative bacteria are generally higher than that of gram-positive bacteria,which can provide certain guidance for the selection of clinical antibiotics.