Monitor position and the accuracy and speed of ultrasound-guided nerve blocks

Abstract

Ultrasound is rapidly becoming an essential skill for all anaesthetists with an interest in regional anaesthesia. Using a single-blinded cross-over trial design, we assessed the accuracy and speed of simulated ultrasound-guided nerve blockade with the monitor either in direct line-of-sight or perpendicular to the line-of-sight. Thirty-one anaesthetists participated in the study. Times taken to reach the targets were similar 18.4 (14.6) s with the monitor 'in-line' and 22.4 (26.7) s with the monitor perpendicular to the target. Needle placement was significantly more accurate when anaesthetists had the monitor in front of them (29 acceptable) than to the side (22 acceptable). For anaesthetists with limited ultrasound experience, the accuracy, but not speed, of ultrasound guided regional anaesthesia can be improved by aligning the monitor in the line of sight of the operator. © 2009 The Authors.