Needle sharpness is minimally affected by vaccine vial puncture.

Abstract

Objective: To survey the commonality of needle-changing practices among veterinarians and measure whether 1 or 2 passages through a vaccine vial septum affects needle sharpness.

Methods: An anonymous online survey of needle-changing behaviors by veterinary professionals was conducted from April to May 2023. Subsequently, a blinded randomized controlled bench trial assessed the impact of septum passage on needle sharpness between June and August 2023 at Midwestern University. Veterinary hypodermic needles of 3 brands and 4 gauges were tested after passing through a septum 0, 1, or 2 times. The primary outcome was the peak penetration force (PF) required to puncture standardized material. Secondary analysis involved visual examination of needles with the use of an optical 3-D surface roughness measurement instrument.

Results: Of 482 survey respondents, 76% routinely changed needles due to concerns about dulling. Experimental results showed a minor increase in PF after 1 (9%) and 2 (18%) septum passages. Needle gauge and brand impacted PF more than septum passage, with differences of 6% to 58% and 9% to 10%, respectively. Visual inspection revealed a 40% incidence of gross defects after 1 passage and 52% after 2 passages, with PF through the vial septum being the strongest damage predictor.

Conclusions: While septum passage slightly increased the PF, brand and gauge had a more substantial impact.

Clinical relevance: This study suggests that changing needles may not be necessary for maintaining sharpness if proper technique is used, potentially reducing the risk of needlestick injuries and medical waste.