# A retrospective case–control study of a cluster of surgical site infections after coronary artery bypass grafting at a tertiary medical center

## TL;DR

A study investigated a cluster of surgical site infections after heart surgery and found ways to reduce infection rates.

## Contribution

The study identified specific risk factors and implemented infection control measures that reduced surgical site infections.

## Key findings

- Lower age and proper perioperative temperature management were independent risk factors for surgical site infections.
- Reducing operating room traffic and limiting wound VAC use helped lower infection rates.
- The infection rate returned to baseline after implementing these measures.

## Abstract

To investigate a cluster of surgical site infections (SSIs) in patients who underwent coronary artery bypass graft (CABG) procedures, identify risk factors for infection, and implement measures to prevent new cases.

The investigation comprised a retrospective case–control study and an observational review of infection control practices between the fall of 2018 and 2019 (study period).

Tertiary care medical center in Florida, USA.

Patients who acquired an SSI following CABG during the study period were defined as case-patients. Control-patients were randomly selected patients who did not acquire a post-CABG SSI.

We recorded clinical and epidemiologic details on a standardized form and analyzed data with SAS statistical software. Odds ratios and 95% confidence intervals were calculated.

Seven patients met the case definition and 21 control-patients were identified. While multiple variables were significant on univariate analysis, after controlling for confounding using multivariate analysis/logistic regression, only lower age (P < 0.0001) and meeting the requirements for appropriate perioperative temperature management (SCIP measure 10) (P = 0.01) were identified as independent risk factors for SSI. Per observational review, measures to reduce operating room traffic and limit door opening/closing were implemented and wound vacuum-assisted closure (VAC) use was phased out. Our institutional SSI rate returned to baseline and no additional clusters were seen in the following three years.

Multiple potential risk factors exist for SSI after coronary artery bypass grafting. At our institution, minimizing operating room traffic and reducing wound VAC use may have successfully addressed these healthcare-associated infections.