Impact of needle bevel position during venipuncture on functional outcomes in hemodialysis patients

A single-center observational study.

Abstract

Introduction: The position of the needle bevel during arteriovenous access cannulation for hemodialysis may influence pain, bleeding, and procedural efficiency; however, existing evidence remains inconsistent. The aim of this research was to assess the potential effect of needle bevel position on hemostasis time, pain intensity, and the occurrence of complications, as well as on delivered dialysis dose and extracorporeal circuit pressures.

Materials and Methods: This was a randomized, controlled, monocentric crossover study conducted between June and July 2025 in a private clinic in Ecuador. Patients with autologous arteriovenous fistulas in use for more than three months were included. Each patient served as their own control. The study duration was four weeks, with two weeks assigned to each bevel position. Descriptive and inferential statistical analyses were performed.

Results: A total of 136 patients were included (3264 punctures), of whom 62.5% were male. No significant differences were observed in arterial (9.92 vs. 9.85 min) or venous (10.38 vs. 10.32 min) hemostasis times, nor in pain scores (1.73 vs. 1.87), according to bevel position. Likewise, no differences were found in delivered dialysis dose (1.82 vs. 1.80) or extracorporeal circuit pressures. Bleeding at the time of puncture was lower when the bevel was positioned downward (12.7% vs. 18.6%; P=0.001).

Conclusions: Needle bevel position does not affect hemostasis time, pain perception, delivered dialysis dose, or extracorporeal circuit pressures. However, a downward bevel position is associated with reduced bleeding during puncture.