Prompt abdominal and pelvic CT to identify source
Surgical/gastroenterology consultation for source control, (debridement, percutaneous drainage), which is the cornerstone of therapy
Blood cultures in severely ill and health care associated complicated infections; peritoneal cultures can help define microbiology
Procalcitonin (PCT) not usually useful
Those who do not meet criteria for severe infection but may have:
SIRS (two or more of: Temperature >38°C or <36°C; Heart rate >90/min; Respiratory rate >20/min; White blood cell count >12,000/mm3 or <4,000mm3)
Co-morbidities (e.g. diabetes, advanced age)
Significant pain
Requiring ICU admission, or
Sepsis (life-threatening organ dysfunction e.g. hypotension, acute renal failure, caused by dysregulated host response to infection)
Acquired in the outpatient setting
Acquired more than 48 hours post admission, or
Hospitalization, surgery, regular outpatient visits (e.g. dialysis, chemotherapy) within last 90 days or residing in long term care
