Use of ultrasound in needle placement in intercostal muscles: A method for increased accuracy in cadavers

Objective: To validate the use of ultrasound technology for the positioning and leveling of intercostal needle placement. Design: Double-blinded experimental study. Setting: An anatomy laboratory. Participants: Two board-certified physical medicine and rehabilitation physicians, 2 first-year medical students, 1 anatomist, and 8 cadavers. Interventions: Four unfixed cadavers were used for unguided needle placement, and 3 unfixed and 1 partially fixed cadavers were used for ultrasound-guided needle placement. Ultrasound-guided needle placement was then confirmed with computed tomography and blind dissection. Main Outcome Measure: The accuracy of needle placement. Results: The unguided study showed needle placement in an intercostal muscle 89% of the time, but in only 15.4% of the time was the correct level sampled. In the 96 needle placements completed, the unguided needle placements had an accuracy of 8.3%, while ultrasound-guided needle placements had an accuracy of 93% (χ² with P<.005). Conclusions: Ultrasound guidance dramatically increases needle placement accuracy for intercostal nerve blocks and intercostal muscle sampling for electromyography.