A Clinical Study On Early Diagnosis Of Sepsis By Applying Serum Procalcitonin

BackgroundSepsis, in addition to coronary heart disease and cancer,has become another major diseases threatening human life.sepsis is the most serious infectious disease caused by pathogenic bacterium's invading into blood circulation. At present, sepsis has become the most serious barrier in hindering further rescue for intensive care patients. It is of great theoretical and clinical value to know more about this complication and take better preventive measures. Therefore, how to predict and diagnose sepsis promptly and accurately, so as to exercise empirical and antibiosis treatment, has always been the issue that scholars studies. However, the present routine diagnosis and identification methods can not meet the clinical need because of long duration in hemoculture and the inadequate sensitivity of CRP and WBC. Procalcitonin (PCT) is a newly found inflammatory factor which functions as a latent diagnostic index in diagnosing systematic sever infection. The semiquantitative method of PCT-Q from BRAHMS is applied to detect a monoclone mouse resistance—katacalcin (a PCT degradation) and colloidal gold (tracer)and multiclone sheep-calcitionin antibody. After the waiting-to-be tested sample was added to the reaction place, tracer was linked with PCT and forms obvious antigen antibody complex. The complex enters viewing area by syphonage, where antigen antibody complex was linked with fixed anti-calcitonin and formed double deck complex. When PCT≥0.5ng/ml, the double deck complex was in red zone and the degree of color is in direct proportion with the density of PCT in sample. Tracer without linkage extended to control plot and formed control red zone after linkage. Calcitonin detection by semiquantitative method is simple, quick, and is of high repeatability and reliability, enjoying high clinical value. This method can be exercised beside the ward, the result of which can be seen in half an hour, enjoying the time superiority than blood culture. To further improving the survival rate of septemia patients, this study tends to clinical significance of calcitonin and regular index in the early diagnosis of sepsis.Methods1. Cases and their grouping180 cases hospitalized in Nanfang Hospital from January to December,2009, are selected.Temperature>38℃or<36℃, heart rate>90, blood culture checkedAccording to the result of blood culture, they are divided into 2 groups:(1) negative sepsis group:90 cases 55 male cases and 35 female case without blood relationship whose age is from 0 to 80. (2) positive sepsis group:90 cases:49 male cases and 41 female cases without blood relationship whose age is from 0 to 85. The difference in age and gender structure is not significant.Diagnosis standardCriteria to judge positive sepsis:1) a clear or suspected local foci of systemic infection; 2) etiological criteria:blood culture or bone marrow culture results positive. criteria to judge negative sepsis:1) clear the local infection focus or suspected systemic infections; 2) etiological criteria:blood culture or bone marrow culture results negative; 3) two or more negative blood culture.2. Experimental methods2.1 Sample testingFast semiquantitative method ((PCT-Q, BRAHMS Diagnostica, Germany) is applied in PCT determination. The experiment is carried out according the instructions and interpreted according to reference card strictly. PCT determination results is divided into 4 classes:PCT<0.5,0.554.4,>8.27,>80.5,≤22.2;Sensitivity are:69.7,56.2,38.1,79.8;Specificity are:69.7,64.8,89.4,49.4.2. Compounding detection2.1 After logistic egression analysis, deleting the diagnosis index with less diagnostic value (P>0.05), egression equation can be:log(p/1-p)=-3.028+1.438×PCT+ 0.008×CRP-0.024×Lym%2.2. Roc curve by PCT-CRP:curve analysis:AUC=0.872 Sensitivity:92.1, specificity:68.52.3. Roc curve by PCT-CRP-lym%:curve analysis:AUC=0.883 Sensitivity:83.1, specificity:81.0.2.2. Roc curve by PCT-lym%:curve analysis:AUC=0.872 Sensitivity:92.9, specificity:69.4.DiscussionInfection, sepsis, shock and MODS are the main causes of death for heavy patients. So the early diagnosis and treatment of infection and sepsis is of great importance. The traditional diagnostic index of infection and sepsis, for instance, temperature, WBC, ESR and CRP are nonspecific. In recent years, newly found early warning index PCT could by found rising significantly after severe infection for 2-3 hours, which demonstrates a high clinical diagnostic value.The ROC could combine the sensitivity and specificity of diagnosis for analysis, which is a common tool for evaluation. The experiment makes it clear that PCT is of great value in the early diagnosis of sepsis. The ROC achieves 0.829, and the AUC of connection parameter ROC is as high as 0.848. Besides, logistic regression analysis is a common statistical method in handling multicriteria in diagnosis. Multi-parameter binary logistic regression analysis is applied in the experiment. The PCT in partial regression coefficient achieved its maximum, further proving that the diagnostic value of PCT is high.The experiment results show that PCT is in high relation with sepsis. PCT, with its high specificity and stable chemical performance, is of high value in the early diagnosis of sepsis. However, with a slightly worse sensibility, it is better to combine it with more sensible index to improve its detecting efficiency. Therefore, PCT is of high practical value in the early diagnosis of sepsis, especially when combined with CRP and Lym% result in the highest AUC and lowest-LR diagnosis method after logistic egression analysis, further explains that PCT could serve for the best treatment of early diagnosis and sepsis.Conclusion1, PCT on sepsis has a high diagnostic value. PCT≥0.5ng/ml as a cut-off point off sepsis2, Lym% in the early diagnosis of sepsis and severity were significantly negative correlation.3, PCT_CRP_Lym% trigeminy enjoys the highest accuracy in the diagnosis of sepsis.4, PCT_CRP& PCT_Lym% joint equivalent diagnostic performance and value combined, in the diagnosis of sepsis.5, PCT levels in the body without changing the gender and age differences, only with the severity of infection.