Effect of Pre-Operative Use of Medications on the Risk of Surgical Site Infections in Patients Undergoing Cardiac Surgery.

BACKGROUND: Median sternotomy, the most common means of accessing the heart for cardiac procedures, is associated with higher risk of surgical site infections (SSIs). A limited number of studies reporting the impact of medication use prior to cardiac surgery on the subsequent risk of SSIs usually focused on antibacterial prophylaxis. The objective of the current study was to evaluate the effect of medications prescribed commonly to cardiac patients on the risk of incident SSIs.

METHODS: The study analyzed data on consecutive cardiac surgery patients undergoing median sternotomy at a McGill University teaching hospital between April 1, 2011 and October 31, 2013. Exposure of interest was use of medications for heart disease and cardiovascular conditions in the seven days prior to surgery and those for comorbid conditions. The main outcome was SSIs occurring within 90 d after surgery. Univariate and multivariate logistic regression (adjusted odds ratio [AOR]) was used to evaluate the effect.

RESULTS: The cohort included 1,077 cardiac surgery patients, 79 of whom experienced SSIs within 90 d of surgery. The rates for sternal site infections and harvest site infections were 5.8 (95% confidence interval [CI]: 4.4-7.3) and 2.5 (95% CI: 1.4-3.7) per 100 procedures, respectively. The risk of SSI was increased with the pre-operative use of immunosuppressors/steroids (AOR 3.47, 95% CI: 1.27-9.52) and α-blockers (AOR 3.74, 95% CI: 1.21-1.47).

CONCLUSIONS: Our findings support the effect of immunosuppressors/steroids on the risk of SSIs and add evidence to the previously reported association between the use of anti-hypertensive medications and subsequent development of infection/sepsis.