INTRODUCTION

Guidelines recommend starting renal replacement therapy (RRT) in critically ill acute kidney injury (AKI) patients according to classic criteria for the initiation of dialysis (CCID). However, comparative data on the presence or absence of CCID in patients receiving continuous veno-venous hemodialysis (CVVHD) or intermittent hemodialysis (IHD) as the initial modality are scarce.

METHODS

Altogether 733 critically ill AKI patients receiving CVVHD or IHD at the research hospital between 2010 and 2019 were screened for this real-world study. All patients on maintenance dialysis were excluded. Patient survival was studied in 662 patients and adverse renal outcomes in 375 surviving patients at 90 days follow-up. The adverse renal outcome was defined as RRT requirement and the secondary outcome was estimated glomerular filtration rate (eGFR) at 90 days follow-up.

FINDINGS

Altogether 472 (71.3%) patients received CVVHD and 190 (28.7%) IHD, and CCID was present at the time of RRT initiation in 250 (37.8%). The CCID was independently associated with mortality in a multivariable logistic regression analysis (odds ratio [OR] 2.226, 95% confidence interval [CI] 1.455-3.407, p < 0.001) adjusted for age, sex, baseline eGFR, disease severity, RRT modality, hypertension, and diabetes. The presence of CCID at the start of RRT was not associated with adverse renal outcome (OR 0.548, 95% CI 0.230-1.305, p = 1.74) nor eGFR (β = 0.155, p = 0.066) at 90 days follow-up. However, starting RRT in the presence of CCID was independently associated with eGFR at 90 days follow-up in a multivariable ordinal regression analysis (β = 0.930, p = 0.018) after adjusting for age, sex, baseline eGFR, disease severity markers, hypertension, and diabetes in patients receiving CVVHD but not IHD as the initial modality.

DISCUSSION

The presence of CCID at the initiation of RRT was associated with mortality but not adverse renal outcomes in this large real-world study on critically ill AKI patients requiring RRT. Initiating RRT in the presence of CCID was associated with improved eGFR at 90 days follow-up in patients receiving CVVHD as the initial modality.