Analysis of pathogens and risk factors of severe acute pancreatitis complicated with infection

Objective To investigate the characteristics of pathogens and risk factors of severe acute pancreatitis (SAP) complicated with infection, so as to provide reference for clinical diagnosis and treatment. Methods From February 2011 to January 2018, at the First Affiliated Hospital of Chongqing Medical University, 438 patients with SAP were selected. The samples including ascites, sputum and blood were collected and cultured. Distribution and drug resistance of pathogens were analyzed. Chi-square test and logistic regression analysis were used for analyzing the risk factors related to SAP complicated with infection. Results The total infection rate of SAP was 49.09% (215/438), of which the bacterial infection rate was 44.29% (194/438) and the fungal infection rate was 22.60% (99/438). A total of 625 pathogens were cultured, including 333 (53.28%) strains of Gram-negative bacteria, 171 (27.36%) strains of Gram-positive bacteria and 121 (19.36%) strains of fungi. Gram-negative bacteria were extremely resistant to β-lactams antibiotics, among them Acinetobacter baumannii was the highest (63.93% to 100.00%), and resistance rate to enzyme inhibitors was slightly lower (11.54% to 48.15%). The resistance rates of Gram-positive bacteria to penicillin and erythromycin were both high, which were 92.86% to 100.00% and 81.25% to 95.00%, respectively, and Gram-positive bacteria resistant to vancomycin, linezolid, and tigecycline were not found. The resistance rate of fungi was generally low (0 to 28.57%). The results of logistic regression analysis showed that multiple organ dysfunction syndrome (MODS) (odds ratio (OR)=2.031, 95% confidence interval (CI)1.230 to 3.356), acute physiology and chronic health evaluation Ⅱ(APACHE Ⅱ) score≥11 (OR=1.780, 95%CI 1.129 to 2.806), fasting time more than three weeks (OR=3.437, 95%CI 2.119 to 5.574), mechanical ventilation (OR=2.697, 95%CI 1.643 to 4.427) and surgery (OR=3.464, 95%CI 1.806 to 6.643) were the independent risk factors of SAP complicated with infection (all P<0.05). The results of stratified analysis indicated that MODS, fasting time more than three weeks, mechanical ventilation and surgery were the independent risk factors of more locus infection (all P<0.05). Conclusions The infection rate of SAP is high and the risk factors are complex. Early prevention, improvement of the pathogen detection and guiding the reasonable use of antibiotics are necessary. For patients with invasive procedures and treatment, aseptic awareness should be strengthen to prevent iatrogenic infection. Key words: Infection; Drug resistance; Risk factors; Severe acute pancreatitis