Abstract: Objective To explore the characteristics and influencing factors of complicated intra-abdominal infection in ICU patients after abdominal surgery.Methods A retrospective study was performed on ICU patients (n=92,observation group) developing complicated intra-abdominal infection after abdominal surgery versus patients (n=104,control group) without complicated intra-abdominal infection after abdominal surgery in our hospital from January 2020 to December 2023.The characteristics of patients who developed complicated intra-abdominal infections were analyzed and the relevant influencing factors were identified using multivariate Logistic regression analysis.Results A total of 124 strains of pathogenic bacteria were isolated and identified in 92 infected patients,with 64.52% (80/124) of Gram-negative strains comprising mainly 29.03%(36/124) of Escherichia coli,25.81% (32/124) of Gram-positive strains comprising mainly 12.90% (16/124) of Enterococcus faecalis,and 9.68% (12/124) of fungi comprising mainly 6.45% (8/124) of Candida albicans.Multivariate Logistic regression results showed that preoperative underlying disease,surgical methods,duration of surgery,invasive procedures ,antibiotic use,and length of ICU stay,enteral nutrition were the influencing factors of complicated intra-abdominal infection in ICU patients after abdominal surgery (P<0.05).Conclusion Patients with complicated intra-abdominal infection are infected with a variety of pathogenic bacteria,predominantly Gram-negative.The patient's preoperative underlying disease,surgical approach,duration of surgery,invasive procedures,use of antibiotics,length of ICU stay,and early enteral nutrition all affect the risk of complicated intra-abdominal infection in ICU patients after abdominal surgery.

Key words: abdominal surgery;intensive care unit;complex intra-abdominal infection;influencing factor