Risk factors for ventilator -associated pneumonia following cardiac surgery

Background: Ventilator-associated pneumonia (VAP) following cardiac surgery is a preventable complication associated with adverse outcomes. Aims: We aimed to assess risk factors and outcomes of VAP following cardiac surgery. Methods: A matched 1:3 case:control study, including adult patients undergoing cardiac surgery through sternotomy between September 2014 and March 2017 was conducted in a tertiary-care hospital in Israel. Cases included all patients developing VAP within 30 days after surgery, defined using consensus criteria. Controls were matched for age, gender and surgery type. Operative data were collected prospectively, other data were collected retrospectively. Cox regression was used for adjusted analysis of matched data. Findings: Out of 946 operated patients, we identified 57 patients with VAP after cardiac surgery (17.7 episodes per 1000 ventilator-days) matched to 149 controls. Significant independent risk factors for VAP included congestive heart failure (odds ratio (OR) 2.357, 95% confidence interval (CI) 1.052-5.281), chest re-exploration in the intensive care unit (OR 10.213, 95% CI 2.235-46.678), preoperative glucose levels (OR 1.1010 per 1 mg/dL increase 95% CI 1.004-1.019) intraoperative red blood cell transfusions (OR 1.542 per 1 unit, 95% CI 1.109-2.094) and pulmonary hypertension (OR 2.261, 95% CI 1.048-6.554). VAP was most commonly caused by Gram-negative pathogens. VAP was associated with higher mortality, longer length of stay, longer need for ventilator support and longer stay in ICU setting. Conclusions: Postoperative VAP in cardiac surgery patients is associated with severe clinical outcomes. We identified risk factors that can aid in preventive measures implementation for high-risk patients. (C) 2020 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.