Profile of Healthcare-Associated Infections Caused by Microorganisms Resistant to Carbapenems and/or Polymyxins and Antimicrobial Consumption in Intensive Care Units: A Multicenter Multimodal Intervention Study

Antimicrobial resistance (AMR) is one of the greatest threats to global health today. Carbapenem-resistant microorganisms (CRM) can cause severe healthcare-associated infections (HAIs) that are difficult to treat in intensive care unit (ICU) patients. To characterize HAIs caused by CRM; to evaluate antimicrobial consumption. Quasi-experimental study conducted in 6 adult ICUs of public hospitals in Greater São Paulo, divided into three phases: observational (08/01/23–10/31/2023), multimodal intervention (11/01/23–04/30/2024), and post-intervention (05/01/2024–10/31/2024). In the first phase, professionals maintained their HAI prevention practices. During the intervention, training sessions were conducted; educational videos and flyers were provided; supplies for hand hygiene and environmental cleaning practices were made available; feedback on HAI prevention practice assessments was provided; posters were displayed. In the post period, the implemented measures were maintained. HAIs were reported according to the diagnostic criteria of the Agência Nacional de Vigilância Sanitária; antibiotic consumption was expressed as Defined Daily Dose (DDD). Seventy-one HAIs due to CRM were reported. In the first phase, the most frequent were central venous catheter-associated bloodstream infection (CLABSI) and urinary tract infection associated with indwelling urinary catheter caused by Klebsiella pneumoniae (both 25%). In the intervention and post phases, the most frequent were CLABSI due to Acinetobacter baumannii (36.4% and 19.2%, respectively) and K. pneumoniae (21.2% and 30.8%, respectively). Regarding mean DDD, there was a reduction in ertapenem when comparing intervention and post phases, from 2.15 to 0.38 (p < 0.05); there was no consumption of ertapenem in the first phase. Other antibiotics decreased when comparing pre and post phases: ceftriaxone, 201.03 and 199.3, respectively; cefepime 19.67 and 13.15 (p < 0.05); meropenem 217.97 and 213.1; polymyxin B 75.57 and 69.93; amikacin 29.87 and 25.25 (p < 0.05). Piperacillin-tazobactam increased in consumption, from 141.07 to 156.73. A. baumannii and K. pneumoniae were the most frequent CRM in ICU HAIs, and the main site was CLABSI. There was a reduction in mean DDDs, except for piperacillin-tazobactam. Characterizing HAIs due to CRM and antimicrobial stewardship combined with a multimodal intervention may contribute to controlling the spread of these agents in healthcare services.