Risk factors for ventilator-associated pneumonia due to multi-drug resistant organisms after cardiac surgery in adults

Background: Ventilator-associated pneumonia (VAP) is one of the most common intensive care unit (ICU)-acquired infections，which can cause multiple adverse events. Due to bacterial mutation and overuse of antimicrobial drugs, multidrug-resistant organisms (MDRO) have become an important group of VAP infections in postoperative cardiac patients. Therefore, the purpose of this study is to explore the risk factors for VAP with MDRO following cardiac surgery in adults. Methods: : The clinical data of adult patients with VAP following cardiac surgery in the hospital from Jan 2017 to May 2021 were analyzed retrospectively, the patients were divided into the MDRO VAP group and the non-MDRO VAP group. Univariable and multivariable logistic regression analyses were performed for the risk factor for the patient with MDRO VAP. The species and drug sensitivity of pathogens isolated from the VAP patients were also analyzed. Results: : A total of 61 VAP cases with 34 cases in the MDRO VAP group (55.7%) and 27 cases in the non-MDRO VAP group (44.3%) were involved in this study. Multivariable logistic regression analysis showed that the independent risk factors for the MDRO VAP included preoperative creatinine clearance rate (CCR) ≥86.6ml, intraoperative cardiopulmonary bypass (CPB) time≥151 mins, postoperative acute kidney injury (AKI) and nasal feeding. Gram-negative bacilli were the main pathogens in VAP patients (n=54, 90.0%), with the highest rate of Acinetobacter baumannii (n=24, 40.0%). Patients with MDRO VAP had significantly longer postoperative intensive care unit (ICU) duration and higher hospitalization costs than non-MDRO VAP patients, but there was no significant difference in the 28-day mortality rate between the two groups. Conclusion: Based on implementing measures to prevent VAP, clinicians should pay more attention to patients with kidney disease, intraoperative longer CPB time, and postoperative nasal feeding to avoid MDRO infections.