Characteristics Of Pathogenic Bacteria And Analysis Of Infection-related Risk Factors In Chronic Refractory Wounds And Construction Of Clinical Prediction Model

Research background and objectiveThe etiology and pathogenesis of chronic refractory wounds are complex and diverse.Local and systemic factors can delay wound healing.Wound infection is one of the main factors.This study analyzed the distribution characteristics of pathogenic bacteria,bacterial resistance characteristics and related risk factors of chronic infectious refractory wounds,established a clinical prediction model and verified its performance,so as to provide help for the prevention and treatment of chronic infectious refractory wounds.MethodsThe clinical data of 292 patients with chronic refractory wounds who were diagnosed and treated in the Plastic Surgery Department of the First Affiliated Hospital of Zhengzhou University from January 2016 to December 2021 and met the inclusion criteria were retrospectively analyzed.According to the pathogen culture results of wound secretion,patients with positive wound secretion culture results were divided into infection group,and patients with negative wound secretion culture results were divided into non-infection group.The distribution of pathogenic bacteria and the bacterial resistance characteristics in the infection group were analyzed and summarized.A total of 16 predictors were included in this study,including age,gender,admission method,long-term smoking,drinking history,diabetes,long-term bedridden history,wound depth to deep skin layer,recent history of dressing change,recent history of surgical treatment,increased C-reactive protein,increased erythrocyte sedimentation rate,and increased procalcitonin,increased white blood cells,decreased hemoglobin,decreased albumin.Univariate logistic analysis and multivariate logistic regression analysis were performed using SPSS 26.0 to screen out independent risk factors related to chronic wound infection.Using R software(R 4.1.2)and rms software package,a clinical prediction model for the risk of chronic refractory wounds complicated by pathogenic bacteria infection was constructed,and the performance of the prediction model was verified.Result1.A total of 292 patients with chronic refractory wounds were included in this study,including 201 cases in the infection group and 91 cases in the non-infection group.The age range of 292 chronic refractory patients in this group was 2-88 years old,the average age was 54(34.0-66.0)years old,and the male to female ratio was 1.50:1.The age range of the patients in the infection group was 2-88 years old,the mean age was 54(36.0-67.0)years old,and the male to female ratio was 1.51:1.The age range of patients in the uninfected group was 9-86 years old,the mean age was 50(32.0-65.0)years old,and the male to female ratio was 1.46:1.In this study,the wound sites of 292 patients included head and neck,chest and abdomen,waist and back,limbs,hips and sacrococcygeal.The limbs were the most common,accounting for 170 cases(58.22%),followed by hips and sacrococcygeal,accounting for 43 cases(14.73%).2.A total of 256 strains of pathogenic bacteria were isolated and cultured from the samples with positive wound secretion culture results,of which Gram-negative bacteria accounted for 54.30%,which was higher than the Gram-positive bacteria accounted for 42.58%.Gram-negative bacteria are mainly Pseudomonas aeruginosa,Klebsiella pneumoniae,Escherichia coli,Enterobacter cloacae subspecies cloacae;Gram-positive bacteria were mainly Staphylococcus aureus,Enterococcus and Streptococcus.The resistance of different types of pathogens to different antibiotics is different.3.According to single factor analysis,age,long term smoking,diabetes,long term bed history,wound depth to deep skin layer,increased C-reactive protein,increased erythrocyte sedimentation rate,increased procalcitonin,increased white blood cell count,decreased albumin and decreased hemoglobin were possible risk factors associated with infection of chronic refractory wounds(P<0.05).Then 11 infection-related possible risk factors were included in multivariate logistic regression analysis,and the results showed that long-term smoking,diabetes,increased C-reactive protein,increased procalcitonin,and decreased albumin were independent risk factors for chronic refractory wound infection(P<0.05).4.Five independent risk factors were used as predictors to construct clinical prediction model and draw the nomogram.The C-index of this model is 0.762,and the corrected C-index obtained by bootsrtap method is 0.747;ROC curve results show that AUC=0.762(95%confidence interval is 0.702-0.822).AUC,C-index and corrected C-index are all between 0.7 and 0.9;the calibration chart shows that the calibration curve of the prediction model is in good agreement with the ideal curve.Conclusion1.This study shows that long-term smoking,diabetes,increased C-reactive protein,increased procalcitonin,and decreased albumin are independent risk factors for pathogenic infection of chronic refractory wounds.2.This study shows that the pathogenic bacteria of chronic refractory wound infection are mostly Gram-negative bacteria,among which Pseudomonas aeruginosa and Escherichia coli account for the highest proportion;among Gram-positive bacteria,Staphylococcus aureus accounts for the highest proportion.According to the distribution of pathogens in chronic refractory wounds and the resistance characteristics of strains,sensitive antibiotics are selected for anti infection treatment,and the relevant risk factors are timely prevented and treated,which is helpful to the clinical treatment of chronic refractory wounds.3.The clinical prediction model of chronic refractory wound infection risk has good performance,good discrimination and calibration,and has certain application value in predicting the risk of pathogenic bacteria infection in chronic refractory wounds.