A bundle including oral antibiotics and mechanical bowel preparation reduces surgical site infections in elective colorectal surgery. pragmatic cohort study

Abstract Introduction The efficacy of perioperative bundled interventions implemented at a multicenter level has been poorly studied. Methods A colorectal 6-element prevention bundle (antibiotic prophylaxis, oral antibiotic prophylaxis (OAP), mechanical bowel preparation (MBP), laparoscopy, normothermia, and wound retractor), introduced in 61 hospitals, was analysed. Surgical site infection (SSI) rates were compared before (G1, 2011–2016), and after (G2, 2016–2020) the bundle implementation. Results 37849 procedures were included. 5462 overall SSI (14.43%), and 2838 (7.5%) organ-space SSI (O/S-SSI) were detected. SSI decreased from 18.38% to 10.62% with the application of the bundle (OR 0,503). Similarly, O/S-SSI diminished from 9.15% (G1) to 5.72% (G2), OR 0.602. Compared to the previous year, SSI decreased by 23% after the first year of bundle implementation. 29.26% of SSIs were diagnosed post-discharge. 54.5% required readmission. The reduction was similar between high, medium and low volume hospitals. Overall SSI was 16.71%, when no measure was applied, and 6.23% when all 6 were implemented. Lack of application of the bundle increased the probability of SSI (OR 3.020) and O/S-SSI (OR 1.556). In a univariate analysis, all measures except normothermia were associated with a decrease in overall SSI, while only laparoscopy and OAP were for O/S-SSI. Multivariate analysis confirmed that laparoscopy, OAP, and wound protectors decrease overall SSI, but only OAP and laparoscopy had an effect on O/S-SSI. Conclusions A preventive bundle decreased overall and O/S SSI rates in elective colon and rectal surgery. The OR for SSI was 1.5 to 3 times higher before than after the bundle implementation.