Low Antithrombin III Activity, Nafamostat Monotherapy without Heparin, and Small Filter Size Are Associated with a Shorter Circuit Lifespan in Pediatric Continuous Kidney Replacement Therapy: A Single-Center Retrospective Cohort Study.

INTRODUCTION

Premature circuit clotting remains a major limitation of pediatric continuous kidney replacement therapy (CKRT). While anticoagulation with heparin or citrate has been well studied, the risk factors for circuit failure under nafamostat mesylate (NM) use have not been well characterized.

METHODS

This retrospective cohort study included pediatric patients aged <16 years who underwent CKRT in a single tertiary care center in Japan. Circuits that were discontinued within 48 h due to clotting were defined as those with a shorter circuit lifespan. Patient demographics, laboratory parameters, and CKRT settings were compared between the circuits with short and long lifespans. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors for a short circuit lifespan, and Kaplan-Meier analysis was employed to assess circuit survival over time.

RESULTS

After excluding circuits associated with extracorporeal membrane oxygenation or elective discontinuation within 48 h, the final analysis comprised 162 CKRT circuits, including 52 circuits (32%) with a short lifespan. By multivariate analysis, low antithrombin III (ATIII) activity before CKRT initiation (odds ratio [OR] 0.97, 95% confidence interval [CI]: 0.95-0.99), NM monotherapy without heparin (OR 0.23, 95% CI: 0.059-0.88), and small filter size (OR: 0.23, 95% CI: 0.077-0.67) were independently associated with a short circuit lifespan. By Kaplan-Meier analysis, circuit survival was significantly longer in patients with an ATIII activity of ≥59% and in those treated with heparin.

CONCLUSIONS

Low ATIII activity, NM monotherapy without heparin, and small filter size were independent risk factors for a shorter circuit lifespan in pediatric CKRT.