Value Of CAR,D-dimer Combined With BUN On The Severity And Prognosis Of Sever Pneumonia In Adults

Objective:To study the value of CAR(c-reactive protein/albumin ratio,D-dimer(D-dimer)combined with BUN(blood urea nitrogen)on admission on the severity of disease and prognosis of adult severe pneumonia.Methods:This study retrospectively collected clinical data of 111 adult patients with severe pneumonia admitted by the Affiliated Hospital of Jiangsu University from January2019 to January 2023.The patients’ age,gender,days of hospitalization,signs on the day of hospitalization,imaging manifestations,laboratory indices on admission and some combined underlying diseases were collected.Patients were divided into three groups according to the CURB-65 and PSI(pneumonia severity index)scores,which are commonly used in severe pneumonia,and the differences in clinical data and laboratory indices were compared among the different groups.The patients were divided into the death group and the survival group according to their hospital outcomes,with 38 cases in the death group and 73 cases in the survival group.The differences in clinical data and laboratory indexes between the two groups were compared.Binary logistic regression was used to analyze the risk factors of patients’ prognosis;interaction analysis was performed to analyze the relationship between CAR,D-dimer,BUN and patients’ combined underlying diseases;and correlation between CAR,D-dimer,BUN and CURB-65 score and PSI score was compared;finally,subject work curve(ROC curve)was used to analyze CAR,D-dimer,BUN dimer,and BUN alone and in combination to predict the prognosis of adult patients with severe pneumonia.Results:(1)The patients were grouped according to the CURB-65 score and divided into20 cases in the low-risk group,56 cases in the intermediate-risk group,and 35 cases in the high-risk group.The gender,temperature,length of stay,respiratory rate,pulse rate,oxygenation index,imaging manifestations of multiple lung lobar infiltrates,combined hypoproteinemia,electrolyte disorders,hepatic insufficiency,thrombophilia,malignancy,hypertension,diabetes mellitus,cerebrovascular disease,coronary artery disease,atrial fibrillation,and laboratory indexes including plasma fibrinogen(FIB),white blood cell count(WBC),hematocrit(Hct)and hemoglobin(Hb),red blood cell count(RBC),total bilirubin(TBIL),alanine transaminase(ALT),glutathione transaminase(AST),blood glucose(BG),and albumin(ALB)were not statistically significant(P > 0.05);while age,mean arterial pressure,combined renal insufficiency,cardiac insufficiency,and chronic obstructive pulmonary disease between the three groups,and laboratory The differences between groups in age,mean arterial pressure,combined renal insufficiency,cardiac insufficiency and chronic obstructive pulmonary disease,and laboratory parameters including D-dimer,CAR,CRP,calcitoninogen(PCT),neutrophil/lymphocyte ratio(NLR),platelet count(PLT),blood creatinine(SCr),and BUN were statistically significant(P < 0.05).(2)Grouped according to PSI score criteria,17 cases could be divided into lowrisk group,45 cases in the medium-risk group,and 49 cases in the high-risk group.The duration of hospitalization,imaging manifestations of multilobar infiltration and admission signs including temperature,respiratory rate,pulse,oxygenation index,mean arterial pressure,combined hypoproteinemia,electrolyte disorders,hepatic insufficiency,thrombophilia,atrial fibrillation,hypertension,diabetes mellitus,coronary artery disease,cerebrovascular disease,and chronic obstructive pulmonary disease,as well as laboratory indices including FIB,PCT,NLR,CAR,CRP,WBC,PLT,TBIL,ALT,AST,and BG were not statistically significant between the groups(P > 0.05);the differences between the three groups in age,gender,combined renal insufficiency,malignancy,and cardiac insufficiency diseases,and laboratory indexes including D-dimer,Hct,Hb,RBC,SCr,BUN,and ALB were statistically significant between the groups(P < 0.05).(3)According to the clinical outcomes of the patients’ hospitalization,the patients were divided into 73 cases in the survivor group and 38 cases in the death group.Age,sex,length of hospitalization,comorbidities ≥3,temperature,respiratory rate,oxygenation index,mean arterial pressure in admission signs,and laboratory indices including FIB,PCT,NLR,CRP,PLT,SCr,WBC,Hct,Hb,RBC,TBIL,ALT,AST,and BG were not statistically different between the two groups(P > 0.05);The differences in pulse,imaging manifestations of multiple lung lobar infiltrates,CURB-65 score,PSI score,and D-dimer,CAR,BUN,and ALB between the two groups were statistically significant(P < 0.05).(4)The results of binary logistic regression analysis showed that the OR(95% CI)for CAR,D-dimer,and BUN were 1.160(1.020-1.320),1.080(1.000-1.160),and1.090(1.030-1.160),respectively.The regression analysis was performed by converting the three indicators,CAR,D-dimer,and BUN,into dichotomous variables,and the results showed that when CAR > 1.515,the OR(95% CI)was 5.370(1.490-19.270);when D-dimer > 2.525 mg/L,the OR(95% CI)was 4.180(1.790-9.750);when BUN >10.64 mmol/L,the OR(95% CI)was 6.620(2.780-15.750).(5)The results of interaction analysis showed that CAR had an interaction with patients’ combined electrolyte disorders and coronary heart disease(P < 0.05);Ddimer had an interaction with patients’ combined hypertension,diabetes mellitus and malignant neoplastic diseases(P < 0.05);and BUN had an interaction with patients’ combined renal insufficiency diseases(P < 0.05).(6)The results of correlation analysis showed that CAR,D-dimer,and BUN were positively correlated with CURB-65 score and PSI score(r > 0,P < 0.05).(7)The results of ROC curve analysis showed that the area under the ROC curve of CAR was 0.639,the optimal cut-off value of CAR was 1.515,the sensitivity was92.1%,and the specificity was 31.5%(P < 0.05);the area under the ROC curve of Ddimer was 0.672,the optimal cut-off value of D-dimer was 2.525 mg/L,the sensitivity was 71.1% and 63% specificity(P < 0.05);the area under the ROC curve of BUN was 0.711,the optimal cut-off value of BUN was 10.64 mmol/L,the sensitivity was68.4% and the specificity was 75.3%(P < 0.05).When the two indices were combined,the area under the ROC curve of CAR+D-dimer was 0.694,the optimal cut-off value was 0.443,the sensitivity was 42.1%,and the specificity was 91.8%(P< 0.05);the area under the ROC curve of CAR+BUN was 0.713,the optimal cut-off value was 0.350,the sensitivity was 63.2%,and the specificity was 71.2%(P <0.05);the area under the ROC curve for D-dimer+ BUN was 0.739,with an optimal cut-off value of 0.385,sensitivity of 60.5% and specificity of 80.8%(P <0.05).When the three indices were combined,the area under the ROC curve for CAR+ D-dimer+BUN was 0.758,with an optimal cut-off value of 0.280,sensitivity of 78.9% and specificity of 64.4%(P < 0.05).Conclusions:CAR,D-dimer,combined with BUN have a clinical predictive value for the severity and prognosis of severe pneumonia in adults;CAR,D-dimer,and BUN are risk factors for poor patient prognosis;and the combined test of CAR,D-dimer,and BUN has the best predictive value for prognosis.