Efficacy And Safety Of Loading Dose Of Polymyxin B In The Treatment Of MDRAB Infection

Objective: In recent years,multi-drug resistant Acinetobacter baumannii(MDRAB)has become a huge threat to human health.Due to the limited treatment of MDRAB infection,a loading-dose polymyxin B treatment plan has been proposed.This study aimed to explore the effectiveness and safety of a loading-dose colistin B combination regimen in the treatment of MDRAB.At the same time,the clinical characteristics and risk factors of death of MDRAB patients were analyzed.Methods: Clinical collection and retrospective investigation of patients with MDRAB and polymyxin B in the First Affiliated Hospital of Nanchang University from January 1,2019 to April 17,2021.The patients were divided into loading dose polymyxin B group(LD group)and non-loading dose polymyxin B group(non-LD group)according to the treatment plan or not.Drug resistance,hospital admission,infection type,gender,age,comorbidities,clinical characteristics,efficacy,adverse reactions and prognosis,etc.,and the risk factors of death were analyzed by comparing the survival group and the death group.Results:(1)Among the sensitivities of MDRAB to 16 commonly used antibiotics,the top three drugs in the MIC range are compound sulfamethoxazole(MIC=2～320 mg/L),piperacillin tazobactam(MIC= 64/4 ～ 128 mg/L),ceftriaxone(MIC=1 ～ 64 mg/L),the lowest resistance rate of MDRAB to polypeptides(polymyxin B)was 0%,followed by tetracyclines(replacement).The resistance rate of cyclocycline was 3.3%,and the resistance rates of other antibiotics were all >75%.(2)A total of 159 patients with MDRAB infection were included in this study,including 110 in the LD group and 49 in the non-LD group.The top five departments of MDRAB for microbial culture were critical care medicine(33.3%),respiratory and critical care medicine.Department of Neurology(22.0%),Neurology(13.2%),Emergency Department(10.1%),Neurosurgery(6.9%).The sources of infection were lung(89.3%),intracranial(2.5%),central venous catheter(1.9%),blood(1.9%),and pus(1.9%).The mortality rates were blood infection(66.6%),urinary system infection(50%),lung infection(33.8%),central venous catheter infection(33.3%),and pus infection(33.3%).(3)There were no significant differences in demographic characteristics,comorbidities and clinical characteristics between the LD group and the non-LD group(P>0.05).There was no statistical difference in the total effective rate between the two groups(P>0.05),but the cure rate of the LD group was 18.2% higher than that of the non-LD group,6.1%,with a statistically significant difference(P<0.05).There was no statistical significance in the safety analysis results between the two groups(P>0.05).(4)The overall in-hospital mortality of MDRAB-infected patients was 33.9%,and the in-hospital mortality of patients in LD group and non-LD group were 28.2% and 46.9%,respectively,and there was a statistically significant difference(P<0.05).(5)Kaplan-Meier survival analysis found that the cumulative survival time of patients in the LD group was significantly longer than that in the non-LD group(average: 78 VS 37days)and there was a statistical difference(P>0.05).(6)Univariate analysis of survival group and death group showed that vasoactive drug treatment(P<0.001),septic shock(P=0.018),central venous catheterization(P=0.003),carbapenems There were significant statistical differences in exposure history(P<0.001),time from hospitalization to infection(P=0.034)and total hospitalization days(P=0.027).(7)The variables with P<0.01 in univariate analysis were included in multivariate logistic regression analysis.The results of multivariate analysis showed that continuous vasoactive drug treatment,central venous catheterization and carbapenem exposure were independent risk factors for death in patients with MDRAB infection.Conclusion:(1)Among the susceptibility of MDRAB to 16 commonly used antibiotics,polymyxin B has the lowest resistance rate,and it needs to be administered in strict accordance with the guidelines for antibiotic treatment to delay the emergence of bacterial resistance.(2)The combination of loading dose of polymyxin B in the treatment of MDRAB infection has a certain correlation with the prolongation of survival time of patients,and does not significantly increase the incidence of adverse reactions.(3)Risk factors for death of MDRAB infection included vasoactive drug therapy,septic shock,central venous catheterization,carbapenem exposure history,time from hospitalization to infection,and total hospitalization days.The need for continuous vasoactive drug therapy,central venous catheterization and history of carbapenem exposure were independent risk factors for death in MDRAB patients.