Hospital- and Ventilator-associated Pneumonia early after Lung Transplantation: a prospective Study on Incidence, Pathogen Origin and Outcome.

Background: Hospital- (HAP) and ventilator-associated pneumonia (VAP) are important complications early (<30 days) after lung transplantation (LT). However, current incidence, associated factors and outcomes are not well reported.

Methods: LT recipients transplanted at our institution (07/2019-01/2020 and 10/2021-11/2022) were prospectively included. We assessed incidence and presentation of pneumonia and evaluated the impact of associated factors using regression models. In addition, we evaluated molecular relatedness of respiratory pathogens collected peri-transplant and at pneumonia occurrence using pulsed-field-gel-electrophoresis (PFGE).

Results: In the first 30 days post-LT, 25/270 (9.3%) recipients were diagnosed with pneumonia (68% [17/25] VAP; 32% [8/25] HAP). Median time to pneumonia was 11 days (IQR 7-13). 49% (132/270) of donor and 16% (44/270) of recipient respiratory peri-transplant cultures were positive. However, pathogens associated with pneumonia were not genetically related to either donor or recipient cultures at transplant, as determined by PFGE.Diagnosed pulmonary hypertension (HR 4.42, 95% CI 1.62-12.08) and immunosuppression use (HR 2.87, 95% CI 1.30-6.56) were pre-transplant factors associated with pneumonia.Pneumonia occurrence was associated with longer hospital stay (HR 5.44, 95% CI 2.22-13.37) and VAP with longer ICU stay (HR 4.31, 95% CI: 1.73-10.75) within the first 30 days post-transplant; 30- and 90-day mortality were similar.

Conclusions: Prospectively assessed early pneumonia incidence occurred in around 10% of LT. Populations at increased risk for pneumonia occurrence include LT with pre-transplant pulmonary hypertension and pre-transplant immunosuppression. Pneumonia was associated with increased healthcare use, highlighting the need for further improvements by preferentially targeting higher-risk patients.