Abstract
BACKGROUND: Smart glasses can provide real-time ultrasonographic images without additional head-eye movement. We investigated whether smart glasses combined with ultrasonography could improve interscalene brachial plexus block (ISB) procedural efficiency. METHODS: This prospective, randomised trial enrolled 151 patients undergoing upper limb surgery requiring interscalene brachial plexus block. Four anaesthesiologists received standardised training in smart glasses-assisted (smart glasses group) or conventional (control group) ultrasound guidance. The primary outcome was total procedure time. RESULTS: Five participants were excluded, and 146 participants were included in the analysis. The total puncture time was shorter in the smart glasses group compared with the control group (124.0 [98.0-155.5 ] s vs 153.0 [123.0-197.5] s; P<0.001). In addition, the ultrasound probe imaging time was better in the smart glasses group than in the control group (19.0 [13.5-30.0] s vs 31.0 [20.0-51.0 ] s; P<0.001), and the period from the first skin puncture to reaching the target area was also shorter (16.0 [12.5-24.5] s vs 26.0 [18.5-33.5] s; P<0.001). Hand-eye coordination was significantly better in the smart glasses group compared with the control group, which included fewer operator head movements (1.0 [1.0-2.0] vs 5.0 [3.0-8.0]; P<0.001); more consistent needle redirections (3.00 [2.0-3.0] vs 3.0 [2.0-4.0]; P=0.004). Pain scores remained similarly low in both groups, with no significant differences in adverse event rates. Ergonomic satisfaction scores (rated 4 or 5) were higher in the smart glasses group (56.2% [41/73] vs 24.7% [18/73]; P<0.001). CONCLUSIONS: Smart glasses reduced the procedure time for experienced anaesthetists performing interscalene brachial plexus block compared with the control group, and improved their hand-eye coordination and satisfaction. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2400091595).