The Impact Of Penicillin Allergy And Alternative Antibiotic Use On Surgical Site Infection After Orthopedic Surgeries And Its Solution

Part 1.Impact of Penicillin Allergy and Alternative Antibiotic Use on Orthopedics Surgical Site Infection:A Cohort StudyBackground and Purpose:Prophylactic antibiotics are used to prevent surgical site infection(SSI),one of the most severe surgical complications,and cephalosporins are used as first-line prophylaxis.This study aimed to analyze the SSI incidence after orthopedic surgeries to elucidate the relationship among different types of SSI after orthopedic surgeries,penicillin allergy(PA)of surgical candidates,and related alternative antibiotic use.Method:In this retrospective cohort study,we compared inpatients with and without PA from 2015.01 to 2021.12.The primary outcome was SSI,and the secondary outcome was SSI sites(superficial,deep,organ/tissue).Moreover,mediation effect analysis was used to explore potential mechanism of action among PA,alternative antibiotic use,and SSI after orthopedic surgeries.Result:Among the 20,022 surgical records,1,704(8.51%)were identified with PA.A total of 111(0.55%)SSI incidents were reported,with 18 cases in PA group(1.05%),and 83 cases in non-PA group(0.51%).Multivariate logistic regression analysis showed that,compared to non-PA patients,PA patients had higher postoperative SSI risk(OR 2.10;95%CI,1.26-3.50;p=0.004),and PA was related to elevated deep or organ/tissue SSI risk.Clindamycin was the most common alternative antibiotic used in PA group.Complete mediation effect of alternative antibiotics on SSI among these patients was found in mediation analysis.Conclusion:Compared to non-PA patients,PA patients developed more SSI after orthopedic surgeries.The elevated infection rate could be secondary to the use of alternative prophylactic antibiotics other than cephalosporins,especially the use of clindamycin.Part 2.Study on the Relationship between Alternative Antibiotic Use and Pathogen Characteristics of SSIBackground and purpose:The first section revealed an elevated SSI rate due to alternative antibiotic use among PA patients.This study aimed to explore the mechanism behind the elevation of SSI caused by alternative antibiotic use in order to optimize prophylactic regimen for PA patients to reduce SSI incidence.Method:The study included patients who developed orthopedic SSIs during 2015.01 to 2021.12 in our center.Patients were divided into those who used alternative antibiotics as study group,and those who used cephalosporins as control group.The primary outcome was the infection rate of different pathogens,and the secondary outcome was the infections of antibiotic-resistant strains and multiple pathogens.The study also analyzed pathogen characteristics of different SSI types and the antibiotic sensitivity profiles of the pathogens.Result:Among the 111 SSI patients identified after orthopedic surgeries,32(28.83%)patients received alternative antibiotics,and 79(71.17%)received cephalosporin as prophylaxis.Gram-positive cocci(GPC,73.82%)were the most common pathogen,followed by Gram-negative bacilli(GNB,16.03%),and Gram-positive bacilli(GPB,6.52%).The infection rate of GPB was higher in the study group than in control group(p=0.001).The infection rates of GPC,GNB,antibiotic-resistant strains,and multiple pathogens were otherwise not statistically different between the two groups.The infection of GNB was more likely in deep SSI(p=0.045)with strains resistant to clindamycin.Antibiotic susceptibility analysis showed an overall of 46.03%resistance rate of all pathogens to clindamycin,all occurring among GPC strains.Result:The SSI pathogen profiles were different between patients who received alternative antibiotics and cephalosporins as prophylaxis.The elevated SSI after the use of alternative antibiotics could be explained by the overall high clindamycin-resistance rate,and low susceptibility of common deep SSI pathogens to clindamycin.Part 3.Feasibility Analysis and Evaluation Workflow Design for Penicillin Allergy Patients to Use Pre-operative Prophylactic CephalosporinsBackground and Purpose:This study aims to assess the allergy history of PA patients who safely used cephalosporins in previous part and establish an evaluation workflow to increase the use of pre-operative prophylactic cephalosporins in PA patients to reduce the incidence of unfavorable outcomes including SSI.Method:The study included patients with PA who received orthopedic surgeries in our center from 2015.01 to 2021.12.PA patients who used alternative antibiotics were the study group,and those who used cephalosporins were the control group.Allergy history characteristics were analyzed between the two groups.An evaluation workflow was established based on the results and literature review to increase the prophylactic cephalosporin use and then validated for its effectiveness.Result:The study enrolled 121 PA patients in the study group and 162 PA patients in the control group.Except for a lower non-allergy reaction reported in the study group than in control group(4.13%vs.11.11%,p=0.034),other allergy history characteristics were comparable between the two groups.An evaluation workflow was established based on literature review and the allergy history characteristics of PA patients who safely used cephalosporin.Result showed that this workflow could augment the use of cephalosporin from 10.36%to 88.43%in PA patients,equal to a reduction of 1 SSI incident for every 226 PA patients evaluated.Conclusion:The history-based evaluation workflow proposed by this study could enhance the use of first-line recommended cephalosporin in 88%of all PA patients.The promotion of this workflow could help reduce SSI incidence after orthopedic surgeries.