Analysis Of Risk Factors And Construction Of Prediction Model For Carbapenem-Resistant Acinetobacter Baumannii Infection

Objective:To analyze and understand the prevalence of Carbapenem-resistant Acinetobacter baumannii(CRAB),antibiotic resistance,and independent risk factors for the infection,and to construct the clinical prediction model and evaluate the predictive ability of the model,so as to provide a basis for rational clinical use and prevention of CRAB infection.This model will provide a basis for rational clinical use and prevention of CRAB infection.Methods:Non-repeated Acinetobacter baumannii(AB)strains were collected from April 2021 to March 2022 from the medical test sections of the two hospital districts of The Affiliated Hospital of Southwest Medical University.The cases of patients infected with the screened AB strains were divided into CRAB group and Carbapenem-sensitive Acinetobacter baumannii(CSAB)group according to the grouping criteria,and the clinical characteristics,drug resistance,and risk factors of the two groups were analyzed.The differences between the two groups were analyzed by χ2 test,Fisher’s exact probability method,and Mann-Whitney U test using SPSS version 19.0.Independent risk factors for CRAB infection were analyzed by multifactorial logistic regression analysis,and nomograph models and prediction equations were constructed for clinical prediction.The predictive ability of the model was assessed using C-index and Area Under Curve(AUC)of the ROC curve.Results:A total of 416 AB strains were screened and 416 cases of AB infection were obtained.257 patients(61.78%)were in the CRAB group and159 patients(38.22%)were in the CSAB group.The department with the most isolated CRAB strains was the Intensive Care Unit(ICU)with 22.18%,followed by the Department of Respiratory and Critical Care Medicine,the Department of Neurosurgery,and the Department of Emergency Medicine with18.68%,17.90%,and 12.84%,respectively.The highest percentage of AB strains was detected in sputum specimens with 77.88%(324 strains).The CRAB strains in this hospital were more than 85% resistant to penicillin,cephalosporins,fluoroquinolones,macrolides,and tetracyclines,and currently only relatively sensitive to cefoperazone sulbactam,polymyxin,and tigecycline.Univariate analysis showed that patients in the CRAB and CSAB groups were statistical differences in combination of chronic cardiovascular disease,cerebral infarction,and malignancy in the underlying disease;in hospital events of days of hospitalization,ICU admission before infection;in invasive operations during hospitalization of use of invasive mechanical ventilation,tracheal intubation or incision,indwelling gastric tube,indwelling urinary catheter,indwelling central venous line,indwelling drainage tube,bronchoscopy;in pre-infection medication of pre-infection antibiotics,carbapenem antibiotics,combination antibiotics;in the 72 hours before infection of white blood cell count(WBC),procalcitonin(PCT),albumin(ALB),and co-infection with other bacteria,(P<0.05).Multifactorial logistic regression analysis showed that the use of invasive mechanical ventilation before infection(P<0.001 OR=2.800),indwelling gastric tube before infection(P<0.001 OR=4.400),and use of carbapenem antibiotics before infection(P<0.001 OR=4.509)were independent risk factors for the development of CRAB infection.The C-index of the predictive model for constructing the nomograph model was 0.809,and the AUC of the ROC curve was 0.813(95%CI:0.771-0.856)for constructing the predictive equation for CRAB infection=-1.299+1.030×invasive mechanical ventilation+1.482×indwelling gastric tube+1.506×use of carbapenem antibiotics.Conclusion:The situation of CRAB resistance in this hospital is serious,and the use of carbapenems before infection,indwelling gastric tube,and invasive mechanical ventilation are independent risk factors for the occurrence of CRAB infection.The constructed prediction model can better predict the risk of CRAB infection in key populations.