It is proposed that ultrasound guidance decreases the risk of intraneural injection and associated postoperative neurological complications. However, the incidence of unintentional intraneural injection with ultrasound is unknown. Two hundred and fifty-seven patients were enrolled in a prospective, single-blind observational study. All patients underwent a pre-operative neurological examination before ambulatory shoulder arthroscopy with sedation and ultrasound-guided interscalene or supraclavicular block. Patients were followed up at 1 week and at 4-6 weeks postoperatively. Two blinded anaesthesiologists viewed the same video of the ultrasound image during the block offline to determine intraneural trespass. Intraneural injection occurred in 42 patients (17%; 95% CI 12-22%). No patient suffered from postoperative neurological complications (0%; 95% CI 0-1.6%) at follow-up.
© 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.