Compliance with an empirical antimicrobial protocol improves the outcome of complicated intra-abdominal infections: a...

Despite improvements in medical and surgical care, mortality attributed to complicated intra-abdominal infections (cIAI) remains high. Appropriate initial antimicrobial therapy (ABT) is key to successful management. The main causes of non-compliance with empirical protocols have not been clearly described.

An empirical ABT protocol was designed according to guidelines, validated in the institution and widely disseminated. All patients with cIAI (2009-2011) were then prospectively studied to evaluate compliance with this protocol and its impact on outcome. Patients were classified into two groups according to whether or not they received ABT in compliance with the protocol.

310 patients were included: 223 (71.9%) with community-acquired and 87 (28.1%) with healthcare-associated cIAI [mean age 60(17-97) yr, mean SAPS II score 24(16)]. Empirical ABT complied with the protocol in 52.3% of patients. The appropriateness of empirical ABT to target the bacteria isolated was 80%. Independent factors associated with non-compliance with the protocol were the anaesthetist's age ≥36 yr [OR 2.1; 95%CI (1.3-3.4)] and the presence of risk factors for multidrug-resistant bacteria (MDRB) [OR 5.4; 95%CI (3.0-9.5)]. Non-compliance with the protocol was associated with higher mortality (14.9 vs 5.6%, P=0.011) and morbidity: relaparotomy (P=0.047), haemodynamic failure (P=0.001), postoperative pneumonia (P=0.025), longer duration of mechanical ventilation (P<0.001), longer ICU stay (P<0.001) and longer hospital stay (P=0.002). On multivariate logistic regression analysis, non-compliance with the ABT protocol was independently associated with mortality [OR 2.4; 95% CI (1.1-5.7), P=0.04].

Non-compliance with empirical ABT guidelines in cIAI is associated with increased morbidity and mortality. Information campaigns should target older anaesthetists and risk factors for MDRB.