Acute kidney injury after lung transplantation, incidence, risk factors, and effects: A Swedish nationwide study.

BACKGROUND

Acute kidney injury (AKI) is a serious complication after lung transplantation, but the reported incidence varies in the literature. No data on AKI have been published from the Swedish lung transplantation program.

METHODS

The aim of our study was to investigate the incidence, perioperative risk factors, and effects of early postoperative acute kidney injury (Kidney Disease Improving Global Outcomes [KDIGO] criteria) after lung transplantation. A retrospective, nationwide study of 568 lung-transplanted patients in Sweden between 2011 and 2020 was performed.

RESULTS

The incidence of AKI (any grade) was 42%. Renal replacement therapy was used in 5% of the patients. Preoperative factors independently associated with increased incidence of AKI were higher body mass index (odds ratio [OR]: 1.07, 95% CI: 1.02, 1.12) longer time on transplantation waiting list (OR: 1.05 [1.01, 1.09]), re-transplantation (OR: 2.24 [1.05, 4.80]) and moderate to severe tricuspid regurgitation (OR: 2.61 [1.36, 5.03]). Intraoperative factors independently associated with increased incidence of AKI were use of cardiopulmonary bypass (OR: 2.70 [1.57, 4.63]), increasing number of transfused red blood cell units, and use of immunosuppressive therapy other than routine (OR: 2,56 [1.47, 4.46]). A higher diuresis (OR: 0.70, 95% CI: 0.58-0.85) was associated with less incidence of acute kidney injury. Development of AKI was associated with increased time to extubation (median 30 h, IQR [9, 118] vs. 6 [3, 16]), length of stay in the intensive care unit (9 days [4, 25] vs. 3 [2, 5]) and increased rate of primary graft dysfunction (OR 2.33 [1.66, 3.29]) and 30-day mortality (OR: 10.8 [3.0, 69]).

CONCLUSIONS

Acute kidney injury is common after lung transplantation and affects clinical outcomes negatively. Preoperative factors may be used for risk assessment. The use of cardiopulmonary bypass is a potentially modifiable intraoperative risk factor.

EDITORIAL COMMENT

Acute kidney injury is a common complication after lung transplantation that severely influences patient outcomes. This large study of more than 500 patients treated over a decade identified potentially modifiable factors associated with the development of acute kidney injury.