[Related factors of in-hospital Acinetobacter baumannii infection after lung transplantation and its impact on postoperative mortality risk].

Objective: To investigate the factors associated with in-hospital Acinetobacter baumannii infection after lung transplantation and its impact on postoperative mortality risk. Methods: A retrospective analysis was conducted on 549 patients who underwent lung transplantation at the Lung Transplant Center of Wuxi People's Hospital Affiliated to Nanjing Medical University between January 2018 and December 2021, with follow-up until 3 years post-transplantation or death. Clinical characteristics and survival data were collected. Patients were divided into an infection group and a non-infection group based on the occurrence of in-hospital Acinetobacter baumannii infection. Differences in clinical features between the two groups were compared. Multivariate logistic regression was used to identify factors influencing in-hospital Acinetobacter baumannii infection post-lung transplantation. Kaplan-Meier survival curves were plotted, and log-rank tests were performed to compare cumulative survival rates at 30 days, 1, 2, and 3 years postoperatively. A multivariate Cox proportional hazards regression model was employed to analyze the impact of Acinetobacter baumannii infection on postoperative mortality risk. Results: The infection group comprised 315 patients [mean age (55.4±11.8) years; 256 males], while the non-infection group included 234 patients [mean age (54.4±12.9) years; 193 males]. The incidence of in-hospital Acinetobacter baumannii infection post-lung transplantation was 57.4% (315/549). Follow-up duration ranged from 1.0 to 36.0 months, with a median of 9.0 months; 257 deaths occurred. The infection group exhibited significantly lower cumulative survival rates at 30 days, 1, 2, and 3 years postoperatively compared to the non-infection group (all P<0.05). Preoperative hospitalization status was a risk factor for in-hospital Acinetobacter baumannii infection, with both general ward admission (OR=6.90, 95%CI:1.45-32.86) and intensive care unit (ICU) admission (OR=2.42, 95%CI:1.13-5.21) associated with higher infection risks than non-hospitalized patients (all P<0.05). No prior anticoagulant use (OR=4.67, 95%CI:1.10-19.74) and donor lung Acinetobacter baumannii culture positivity (OR=17.69, 95%CI:5.37-58.33) were identified as risk factors for postoperative in-hospital Acinetobacter baumannii infection. Multivariate Cox analysis revealed that in-hospital Acinetobacter baumannii infection increased mortality risk at 1 year (HR=1.55, 95%CI:1.11-2.19), 2 years (HR=1.63, 95%CI:1.20-2.23), and 3 years (HR=1.53, 95%CI:1.15-2.04) postoperatively (all P<0.05), but its impact on 30-day mortality (HR=1.53, 95%CI:0.92-2.54) was not statistically significant. Conclusions: Preoperative general ward admission, ICU admission, no prior anticoagulant use, and donor lung Acinetobacter baumannii culture positivity are risk factors for in-hospital Acinetobacter baumannii infection post-lung transplantation. In-hospital Acinetobacter baumannii infection increases mortality risk at 1, 2, and 3 years postoperatively.