Accelerated Venovenous Hemofiltration as a Transitional Renal Replacement Therapy in the Intensive Care Unit

Abstract

Background: Continuous renal replacement therapy (CRRT) is commonly employed in the intensive care unit (ICU), though there are no guidelines around the transition between CRRT and intermittent hemodialysis (iHD). Accelerated venovenous hemofiltration (AVVH) is a modality utilizing higher hemofiltration rates (4–5 L/h) with shorter session durations (8–10 h) to “accelerate” the clearance and volume removal that normally is spread out over a 24-h period in CRRT. We examined AVVH as a transition therapy between CRRT and iHD, with the aim of decreasing time on CRRT and providing a more graduated transition for hemodynamically unstable patients requiring RRT. Methods: Retrospective cohort study describing the clinical outcomes and quality initiative experience of the integration of AVVH into the CRRT program at an academic tertiary care center. Outcomes of interest included mortality, ICU length of stay and readmission rates, and technical characteristics of treatments. Results: In total, 97 patients received a total of 298 AVVH treatments (3.1 ± 3.3 treatments per patient). Totally, 271/298 (91%) treatments were completed successfully. During an average treatment time of 9.5 ± 1.6 h with 4.2 ± 0.5 L/h ­replacement fluid rate, urea reduction ratio was 23 ± 26% per 10-h treatment, and net ultrafiltration volume was 2.4 ± 1.3 L/treatment. Inpatient mortality was 32%, mean total hospital length of stay was 54 ± 47 days. Sixty-four out of 97 (66%) patients recovered renal function by discharge. Among those who transferred out of the ICU, 7/62 (11%) patients required readmission to the ICU after developing hypotension on iHD. Conclusion: AVVH can serve as a transition therapy between CRRT and iHD in the ICU and has the potential to decrease total time on CRRT, improve patient mobility, and sustain low ICU readmission rates. Future study is needed to analyze the implications on resource use and cost of this modality.

Ensuring Sustainability of Continuous Kidney Replacement Therapy in the Face of Extraordinary Demand: Lessons From the COVID-19 Pandemic

“…It may be possible to treat 2 patients per machine within a 24-hour period by compressing the run of KRT to 10 to 12 hours at correspondingly higher clearance to compensate for efficacy. 40,41 This accelerated KRT could be run as hemodiafiltration to optimize both dialysate and replacement fluid pumps and accommodate the doubled fluid consumption rate. Admittedly such therapy would consume at least 1 filter per patient treatment; moreover, the higher ultrafiltration rate could induce hemodynamic instability.…”

Association between Prolonged Intermittent Renal Replacement Therapy and All-Cause Mortality in COVID-19 Patients Undergoing Invasive Mechanical Ventilation: a Retrospective Cohort Study

“…Prolonged intermittent renal replacement therapy (PIRRT), as a cost-effective alternative, has been used in the intensive care unit (ICU) (21, 22). To date, no specific treatment has been confirmed to be effective for COVID-19, and supportive treatment remains essential.…”

COVID-19 and the Inpatient Dialysis Unit

“…SLED uses standard machines, and lower dialysate and blood-flow rates over a longer time period (9). Prolonged intermittent RRT uses CRRT machines running at higher prescribed clearances for 8-12 hours before moving the machine to the next patient (10,11). Many centers will have both types of machine, so it is imperative to think broadly about available resources and how to use them in surge capacity.…”