Complicated intra-abdominal infections (IAIs) remain a major challenge in clinical practice. In addition to significant morbidity and mortality for patients, they consume substantial hospital resources. This is compounded by the potential misuse of antimicrobial agents that may result in suboptimal treatment, as well as encourage the selection and spread of antibiotic-resistant microorganisms in the health care setting. The present guideline was developed jointly by the Canadian Surgical Society (CSS) and the Association of Medical Microbiology and Infectious Disease (AMMI) Canada. The primary goal was to provide updated recommendations for the medical and surgical management of complicated IAIs since publication of the 2003 antimicrobial treatment guideline by the Infectious Diseases Society of America (IDSA) (1). Particular focus is directed at risk stratification for poor outcome based on epidemiological studies, current status of antimicrobial susceptibility and resistance profiles among enteric pathogens, therapeutic efficacy of antimicrobial regimens based on randomized clinical trials, operative versus percutaneous approaches for source control, the role of intraabdominal hypertension (IAH) and abdominal compartment syndrome (ACS) in IAI, and infection control and preventive measures for postoperative IAIs and surgical site infections. An additional objective is to categorize the recommendations according to the strength and quality of the available evidence using a standardized grading system. Importantly, the current guideline provides recommendations for initial empirical antimicrobial management of complicated IAIs based on clinical settings and issues unique to the Canadian health care system.Summarized below are the key evidence-based recommendations grouped according to the main sections discussed in more detail in the guideline. Each recommendation is rated by the strength of support (category A to C) and quality of evidence (grade 1 to 3) as assessed by the working group of the guideline.
Key recommendations for risk assessment and stratificationRecommendation 1. Categorize the severity of illness by using the Acute Physiology and Chronic Health Evaluation II (APACHE II) score: low-moderate (lower than 15) or high (15 or greater) (A-2 evidence). Although the APACHE II scoring is infrequently used clinically outside of the critical care setting at present, it is recommended that physicians and surgeons consider introducing it into clinical use in patients with IAIs. A user-friendly APACHE II calculator can be found on the following Web site . Recommendation 2. Identify high-risk patients for poor outcome by stratification according to community-acquired versus health care-associated IAIs, previous antibiotic exposure, and underlying comorbid conditions such as diabetes, severe cardiopulmonary disease or immunosuppression (A-2 evidence) Recommendation 3. Use the severity of illness score (APACHE II) and other risk factors outlined above to plan appropriate medical or ...