Could ultrasonography be used by an anaesthetist to identify a specified lumbar interspace before spinal anaesthesia?

Abstract

Insertion of a needle into the lumbar subarachnoid space may cause damage to the spinal cord. Current techniques to identify a safe interspace have limitations. Ultrasound was investigated as a means to improve anatomical accuracy. Seventeen patients attending for elective magnetic resonance imaging (MRI) of the spine were studied. Ultrasonic identification of the L3-4 interspace was attempted by an anaesthetist and a marker was placed. A radiologist identified the anatomical location of the marker on the MRI scan. Thirteen out of 17 markers were at the L3-4 interspace; four were at the L2-3 interspace. These results suggest that ultrasonography may be a useful adjunct to safe subarachnoid anaesthesia.