Management of Asymptomatic Bacteriuria in Patients Scheduled for CABG

Definition and Prevalence

• Asymptomatic bacteriuria (ASB) is defined in men as a clean-catch urine sample with ≥10⁵ CFU/mL of a single bacterial species, or a catheterized urine sample with ≥10² CFU/mL of a single bacterial species 2
• The prevalence of ASB varies by population, with higher rates in elderly patients and those with indwelling catheters 3

Evidence Against Treatment Before CABG

• The Infectious Diseases Society of America (IDSA) guidelines strongly recommend against screening for or treating ASB in patients undergoing elective non-urologic surgery 1
• There is no evidence that treating ASB before non-urologic procedures like CABG provides any benefit in preventing surgical site infections or other complications 1

Risks of Unnecessary Treatment

• Treatment of ASB promotes reinfection with organisms that have increased antimicrobial resistance 1
• Antimicrobial therapy carries risks of adverse effects including Clostridioides difficile infection 1

When Treatment IS Indicated

• Treatment of ASB is only recommended in the following specific situations:
  • Pregnant women 4
  • Patients undergoing urologic procedures with anticipated mucosal bleeding 5, 6
  • When patients develop symptoms of urinary tract infection 1

Appropriate Management for CABG Patients

• The American College of Cardiology and other guideline societies, as summarized by the Infectious Diseases Society of America, recommend that patients scheduled for CABG should not be screened for ASB 1
• If urine culture results are already available and positive, the Infectious Diseases Society of America recommends not treating ASB unless the patient has symptoms of UTI 1
• Standard perioperative antimicrobial prophylaxis for the CABG procedure should be administered according to surgical protocols, regardless of urine culture results, as recommended by the Infectious Diseases Society of America 1