Y WANG1, M GALLAGHER1, Q LI1, R BELLOMO2
1The George Institute For Global Health, Newtown, Australia, 2Austin Health, Heidelberg, Australia
Aim: To identify the predictors for renal recovery to dialysis independence at day 28 in critically ill patients with severe acute kidney injury (AKI) requiring renal replacement therapy (RRT).
Background: Recovery of kidney function is a fundamental outcome for survivors of critical illness. Different modalities of renal replacement therapy (RRT) may impact renal recovery.
Methods: The IMPROVE-AKI study was an individual patient data meta-analysis of previous RCTs of RRT dose intensity in severe AKI to assess the effects of RRT dose intensity on RRT independence. Baseline variables including demographic characteristics, disease severity and RRT characteristics were collected. The primary outcome was successful renal recovery to dialysis independence at day 28, defined as no requirement of RRT by day 28. Predictors for renal recovery were analysed using logistic regression analysis.
Results: The IMPROVE-AKI study included 7 RCTs and 3575 patients. Among them, 1926 patients had data on recovery or failed recovery to RRT independence at day 28. Baseline mechanical ventilation (OR 0.70, 95% CI 0.50-0.99, P=0.047) and low pH (OR 0.18, 95% CI 0.05-0.71, P=0.014) predicted decreased likelihood of recovery, while higher baseline urine output (OR 1.21, 95% CI 1.18-1.24, P=0.000), and use of Continuous RRT instead of intermittent RRT (OR 3.04, 95% CI 2.13-4.35, P=0.000) predicted successful renal recovery at day 28. Initial modality of dialysis (i.e. CRRT vs IRRT) was the strongest predictor for renal recovery. The presence of pre-existing CKD did not affect renal recovery in a sensitivity analysis.
Conclusions: Initial dialysis with CRRT predicted better renal recovery in patients with severe AKI. Further large RCTs are needed to assess effects of different modalities of dialysis on renal recovery in severe AKI patients.
Dr Amanda Wang is a nephrologist and post-doctoral research fellow at the George Institute for Global health, with research interest of acute kidney injury and dialysis.