The echogenicity of nerve blockade needles.

Abstract

We performed a prospective, randomised study to evaluate the echogenicity of 11 regional block needles when inserted into a gel phantom at 45° in the ultrasound plane. Two hundred anaesthetists viewed in random sequence recordings of each needle as it was advanced into the phantom. Participants scored the needle for echogenicity on a scale of 0-10 and categorised the needle as 'hyperechoic' or 'standard'. The mean (95% CI) echogenicity score was 1.7 (1.4-2.0) units higher for three needles marketed as 'hyperechoic' compared with standard needles marketed by the same companies, p < 0.001. The odds ratios (95% CI) that an anaesthetist would categorise a needle as hyperechoic were: 5.3 (3.6-8.0) if the needle was marketed as hyperechoic, p < 0.001; and 1.7 (1.1-2.6) if regional anaesthetic experience was ≥ 1 year compared with < 1 year, p = 0.025.