A 13-Year Retrospective Analysis of Acute Kidney Injury Requiring Renal Replacement Therapy in Non Renal Solid Organ Transplantation.

Abstract

Acute kidney injury (AKI) requiring renal replacement therapy (RRT) is associated with high mortality and progression toward chronic kidney disease (CKD). A few studies analyzed the impact of AKI in non renal solid organ transplant (NRSOT) recipients. The aim of this study was a 13-year retrospective analysis of AKI in NRSOT recipients identifying its clinical relevance on outcome and progression toward CKD. We analyzed (2001-2013) the percentage of NRSOT in the AKI population treated by RRT in our University Hospital. For each NRSOT recipient, we evaluated RIFLE, SOFA and the severity index ATN_ISS at RRT start. The percentage of AKI requiring RRT in the NRSOT population and for distinct transplanted organ (liver, heart or lung graft) was studied. Renal function (eGFR) was evaluated at the end of observation (30 days). We treated by RRT 2648 critically ill patients with AKI for a total of 20932 sessions performed: 291/2648 (10.99%) were NRSOT recipients. In the study period, 1673 liver, 317 heart and 34 lung transplantations were performed. We treated by RRT 174/1673 (10.4 %) liver, 83/317 (26.2 %) heart and 34/110 (30.9%) lung transplanted patients. NRSOT patients’ characteristics were: age 59.8±7.6 yrs, male 67.7%, serum creatinine 3.88±1.27 mg/dl, SOFA 12.8±3.1, RIFLE (Risk 12%, Injury 17.2%, Failure 70.8%) and ATN_ISS score 0.8±0.11. The prevalent cause of AKI was sepsis (44%). Mortality rate of NRSOT patients treated by RRT was 44.3% (129/291), 42.5% (74/174) for liver, 49.4% (41/83) for heart and 41.2% (14/34) for lung recipients, respectively. AKI was a complication of the early post-transplantation period since the need for RRT occurred in the first 30 days after surgery in 69.1% of NRSOT recipients (64.9% for liver, 60.2% for heart and 82.3% for lung, respectively). In survivors, mean serum creatinine at the end of the study period was 2.37±0.82 mg/dl (1.88±0.94 mg/dl in liver, 2.42±0.75 mg/dl in heart and 2.81±0.92 mg/dl in lung graft recipients, respectively). Our retrospective analysis revealed an increased incidence of AKI mainly due to sepsis in the NRSOT population. The occurrence of AKI requiring RRT in the first 30 days after transplantation was associated with a worse outcome and with progression toward CKD in survivors.