ObjectiveTo determine the rate of the acute respiratory distress syndrome (ARDS) after kidney transplantation and to identify risk factors associated with the development of ARDS after kidney transplantation and outcomes for patients diagnosed with ARDS in this setting.DesignRetrospective analysis of the national registry for end-stage renal disease in the United States.PatientsWe studied all patients who underwent kidney transplantation between July 1, 1994 and June 30, 1998 and identified patients diagnosed with ARDS. The diagnosis of ARDS was based on coding of patients records. We also compared the rate of ARDS after kidney transplantation with the rate of ARDS in the remainder of the U.S. population based on the results of the National Hospital Discharge Survey for 1997.Measurements and Main ResultsDuring the study period, 42,190 kidney transplantations were performed in the United States and ARDS was diagnosed in 86 of these subjects (0.2%) resulting in an annualized rate of ARDS of 51.0 cases per 100,000 patients per year. The rate of ARDS after kidney transplantation was significantly higher than the reported rate of ARDS in the U.S. population (p< .050). Demographic factors, indications for transplantation, comorbid illness, antigen mismatch, cytomegalovirus status, and development of rejection did not correlate with the development of ARDS. Of the immunosuppressive agents (e.g., cyclosporine, FK-506, mycophenolate mofetil, azathioprine, OKT-3, antilymphocyte globulin), only the use of antilymphocyte globulin when used to treat rejection was linked with an increased risk for ARDS (odds ratio: 3.85; 95% confidence interval: 1.36 to 10.87). Subjects with graft failure were 2.70 (95% confidence interval: 1.33 to 5.52) times more likely to develop ARDS. The 28-day mortality in subjects with ARDS was 52.1%. The 3-yr survival after kidney transplantation was 88.9% in those without ARDS compared with 57.8% in persons with ARDS (p< .001).ConclusionsAlthough ARDS is a rare event after kidney transplantation, undergoing renal transplantation increases the risk for ARDS. Among patients receiving kidney transplants, graft failure and the use of antilymphocyte globulin for rejection are associated with the development of ARDS. Patients who develop ARDS after kidney transplantation face significant mortality.