Independent risk factors for ventilator-associated pneumonia after cardiac surgery

Abstract

Objective: To investigate the related factors and pathogens of ventilator-associated pneumonia (VAP) after heart surgery so as to provide evidences for clinical prevention and therapy.

Methods: In total 1,688 cases were collected from January 2004 to January 2011. Overall 105 patients developed VAP. Retrospectively analyzed these patients after heart surgery to determine the clinical data, pathogens and treatment measures.

Results: The frequency of ventilator-associated pneumonia was 6.2% (105/1 688), and mortality was 25.7% (27/105), 198 pathogen strains were isolated by bacterial culture, in which Gram negative bacteria accounted for 69.2% (137/198), Gram positive bacteria 27.8% (55/198), and fungi 3.0% (6/198). The independent risk factors for VAP after cardiac surgery were: age >70 (p < .01), emergent surgery (p < .01), perioperative blood transfusions (p < 0.01), reintubation (p < .01) and days of mechanical ventilation (MV) (p < .01). Median length of stay in the ICU for patients who developed VAP or not was, respectively, (24.7 ± 4.5) days versus (3.2 ± 1.5) days (p < .05), and mortality was, respectively, 25.7% versus 2.9% in both populations (p < .05).

Conclusion: Age >70, emergent surgery, perioperative blood transfusions, reintubation and days of MV are the risk factors for VAP in patients following cardiac surgery. P. aeruginosa, P. klebsiella, S. aureus, and Acinetobacter baumannii were the main pathogens of VAP. According to the cause of VAP, active prevention and treatment measures should be developed and applied to shorten the time of MV and improve chances of survival.

Keywords: cardiac surgery; pathogen; risk factor; ventilator-associated pneumonia (VAP).