Insights Into the Characteristics, Prescription and Delivery of Continuous Renal Replacement Therapy to Critical Ill Patients - The iCRRT Data Registry

1.0 Rationale The goal of this study is to develop a large repository of data on CRRT practices and outcomes, enabling characterization of similarities and differences in standard CRRT practices across medical centers. Natural variability in practices will provide an opportunity to compare outcomes associated with different practice patterns and generate important preliminary data to inform future interventional trials.

2.0 Background Despite the accumulation of high-quality evidence, the prescription, delivery, and maintenance of continuous renal replacement therapy (CRRT) remain highly variable across clinical settings. This persistent heterogeneity reflects uncertainty in key aspects of CRRT practice and underscores the need for a comprehensive, international evaluation. The international CRRT (iCRRT) initiative was established to systematically characterize global CRRT practices, identify regional variation, and inform strategies to optimize the delivery of this life-sustaining therapy for critically ill patients.

Acute kidney injury (AKI) is among the most common and severe complications encountered in critical illness, affecting more than half of patients admitted to intensive care units (ICUs). Approximately 6% of ICU patients require renal replacement therapy (RRT), a subgroup in whom hospital mortality remains exceedingly high, frequently approaching or exceeding 50%. Although AKI is associated with substantial morbidity, mortality, and healthcare utilization, no interventions have been shown to consistently reverse established kidney injury. Management, therefore, remains largely supportive, with RRT reserved for patients with advanced or refractory disease.

For critically ill patients, particularly those with hemodynamic instability, CRRT has become the predominant RRT modality in many high-income countries. Since the original description of continuous arteriovenous hemofiltration more than three decades ago, technological and procedural advances have transformed CRRT into a widely adopted and routinely applied therapy. Compared with intermittent hemodialysis (IHD), CRRT offers superior hemodynamic tolerance, continuous solute control, and more precise fluid management. These perceived advantages form the basis of the 2012 Kidney Disease Improving Global Outcomes (KDIGO) guidelines, which recommend CRRT over intermittent modalities in hemodynamically unstable patients . Nevertheless, despite its central role in contemporary critical care, substantial variation in CRRT practice persists across institutions and individual providers.

At the same time, there is increasing recognition that traditional clinical outcomes alone may incompletely capture the impact of critical illness and its treatments. Evidence increasingly supports the routine use of patient-reported outcome measures (PROMs) to improve patient-clinician communication, enhance patient satisfaction, and positively influence health-related quality of life (HRQL). In this context, the Alberta-based EMPATHY study is evaluating the effectiveness and cost-effectiveness of systematic PROMs collection in chronic RRT programs, examining associations with patient experience, clinical outcomes, HRQL, and healthcare utilization.