Cerebral microembolic load during continuous versus intermittent renal replacement therapy in critically ill patients...

Microemboli generated during kidney replacement therapy (KRT) may contribute to cerebro-vascular injury in patients with acute kidney injury. Whether different KRT modalities influence cerebral microembolic burden remains uncertain.

In this single-center, prospective, randomized controlled trial, intensive care unit patients with dialysis-dependent acute kidney injury receiving continuous renal replacement therapy (CRRT) were randomized to continue CRRT or convert to intermittent therapy (IRRT). Doppler assessments were performed during baseline CRRT and after randomization during CRRT or during the first IRRT session after a KRT-free interval. The primary outcome was the between-group difference in total cerebral microemboli count between baseline and the post-randomization assessment. Secondary outcomes included cerebral microemboli type and rates, extracorporeal venous microbubble counts and rates, 30-day mortality, and intensive care unit length of stay. The study was terminated early for technical reasons.

Thirty-eight patients were analyzed (CRRT, n = 24; IRRT, n = 14). The median between-group difference in total cerebral microemboli count from baseline to post-randomization assessment was -216 events over 30 minutes (95% Confidence Interval (CI) -919 to 246; P = .79). Venous microbubble counts increased during CRRT but decreased during IRRT, with a between-group difference of -36 975 events (95% CI -63 621 to -15 899; P < .001). No significant differences were detected in 30-day mortality or intensive care unit (ICU) length of stay.

This exploratory study did not detect a statistically significant difference in cerebral microembolic burden between modalities. Larger studies are needed to clarify the clinical and neurological relevance of microembolization during kidney replacement therapy.