Bacteriuria is not associated with surgical site infection in patients undergoing cardiovascular surgery

Background: Despite absence of evidence, in practice, asymptomatic bacteriuria is perceived as a risk factor for surgical site infection (SSI) among patients with cardiac surgery. We aimed to identify whether an association exists between the preoperative presence of asymptomatic bacteriuria or urinary tract infection and SSI in patients undergoing cardiovascular surgery.

Methods: This is an analytical study with a retrospective cohort of patients undergoing coronary revascularization or valve replacement surgery. We identified cases of bacteriuria, urinary tract infection, and cardiovascular SSI and adjusted the results according to exposure to antibiotics and known risk factors for SSI using a multivariate logistic regression analysis.

Results: A total of 840 patients were included in the study, of whom 33 (3.9%) had asymptomatic bacteriuria and 13 (1.5%) had urinary tract infections. The incidence of SSI was 9.5% (80 patients), with 2.3% of cases having mediastinitis. In the multivariate analysis, asymptomatic bacteriuria (relative risk, 0.83; 95% confidence interval, 0.26-2.56; P = .74) and urinary tract infection (relative risk, 2.54; 95% confidence interval, 0.60-10.69; P = .20) were not risk factors for SSI. Traditional risk factors were found to increase the risk of SSI.

Conclusions: The presence of bacteriuria is not a risk factor for presenting SSI in cardiovascular surgery. Screening with urinalysis or urine culture would not be recommended for patients undergoing cardiac surgery.