Changes Of Level Of Serum Procalcitonin And Its Clinical Significance During The Early Phase Of Extensive Burn

Background Sepsis is a common complication and the main cause of death of extensive burn.Prompt and accurate diagnosis of sepsis is important for burn treatment.But,it is difficult to diagnose sepsis due to systemic inflammatory reaction and organ function damage caused by burn stress.Serum procalcitonin,as a biomarker of stress,has a definite role in the diagnosis of sepsis in the middle and late stage of extensive burn.However,there is no systematic study on the change pattern and clinical significance in the early stage of burn.Objective The aim of this study was to analyze the changes of level of serum procalcitonin(PCT)and its influencing factors in the early phase of extensive burn,and to investigate its potential and clinical significance for sepsis prediction and prognosis.Methods Clinical data of 324 patients with extensive burns(>30%TBSA)treated at our department from July 2014 to July 2020 were retrospectively analyzed.The following clinical date and treatment information of patients were collected: essential information,cause of injury,degree of inhalation injury,total burn surface area,vital signs,data of inspection,laboratory test results,serum PCT concentrations,length of stay,incidence data of sepsis,prognosis,etc.Patients’ burn index,admission APACHE-II score and admission SOFA score were calculated.Bivariate logistic regression analysis was used to identify the risk and prognostic factors associated with sepsis in patients with extensive burns,and receiver operating characteristic(ROC)curves were plotted to analyze the ability of PCT concentrations in the early stage of extensive burn to predict sepsis and prognosis.The t-test and Mann-Whitney U test ware used to compared the statistical differences of parameters,and linear regression was used to investigate the influencing factors of PCT concentration changed during the early phase.Spearman correlation coefficient was used to analyze the correlation between PCT and some burn evaluation indexes.Results Approximately half of the patients(50.93%)exhibited elevated serum PCT concentrations(≥2.00ng/ml)during the early phase of extensive burn.However,according to the sepsis consensus of the 2007 American Burn Association,no infection or sepsis occurred in these patients of the period,suggesting that elevated PCT concentrations at this stage may not be caused by infections.Early-phase PCT concentration was an independent risk factor(OR=1.135,P=0.044)for sepsis occurrence in extensive-burn patients within 60 days of injury.The area under the ROC curve for predicting the onset of sepsis was0.823(95%CI 0.737～0.909,P < 0.01),and the optimal threshold and corresponding sensitivity and specificity were 4.275ng/ml,75.5%,and 83.1%,respectively.The concentration of PCT in the early phase was positively correlated with the burn index.Stratified analysis showed that there was significant difference in the concentrations of PCT during the early phase between sepsis patients and non-sepsis patients.Bivariate logistic regression analysis showed that sepsis occurrence(OR=131.312,P=0.006),admission APACHA-II score(OR=1.347,P=0.025),burn index(OR=1.139,P=0.034),admission PCT concentration(OR=1.271,P =0.024),age(OR=1.077,P =0.016)were the risk factors for death within 90 days in patients with extensive burn,and ROC curve analysis indicated that the predictive power of the above factors decreased in turn.Burn index(B=0.031,P<0.01),degree of inhalation injury(B=1.172,P=0.006),and admission APACHE-II score(B=0.910,P<0.01)influenced PCT concentration elevation during the early phase.Correlation analysis confirm that the PCT concentrations during the early phase and burn index(r=0.573,P<0.001),the degree of inhalation injury(r=0.642,P<0.001),APACHE-II score(r=0.767,P<0.001)are highly correlation in terms of assessing the severity of burns,and at the same time,the admission PCT concentrations also have some implications to ICU hospitalization days(r=0.359,P < 0.001)and the medical costs(r=0.305,P<0.001)of burn patients.Conclusions During the early phase of extensive burns,PCT levels increased in approximately 50.93% of the extensive-burn patients,which were not related to infection,but related to non-infectious factors such as burn index,admission APACHE-II score,degree of inhalation injury,and so on,which determined the severity of burns.As elevated PCT level during the early phase predicted sepsis occurrence within 60 days of injury and was significantly associated with patient mortality,it might be a potential burn severity indicator during the early phase of burn injury.