Identification of the epidural space with optical spectroscopy: an in vivo swine study.

Anesthesiology 113(6):1406-18 (2010) PMID 21068654

Accurate identification of the epidural space is critical for safe and effective epidural anesthesia or treatment of acute lumbar radicular pain with epidural steroid injections. The loss-of-resistance technique is commonly used, but it is known to be unreliable. Even when it is performed in conjunction with two-dimensional fluoroscopic guidance, determining when the needle tip enters the epidural space can be challenging. In this swine study, we investigated whether the epidural space can be identified with optical spectroscopy, using a custom needle with optical fibers integrated into the cannula.