Influence of prior opioid exposure on diagnostic facet joint nerve blocks

To determine the influence of prior opioid use on the diagnostic validity of controlled comparative local anesthetic blocks in the diagnosis of facet joint involvement in chronic spinal pain.

Data were evaluated from 438 patients with chronic spinal pain who underwent diagnostic facet joint nerve blocks. Patient data were divided into four groups based on the level of opioid use: group I (no opioid use), group II (low opioid use), group III (moderate opioid use), and group IV (high opioid use). Facet joint involvement was diagnosed utilizing controlled comparative local anesthetic blocks with 1 percent preservative-free lidocaine and 0.25 percent preservative-free bupivacaine.

Prior and current opioid use did not show relationship to the diagnostic validity of controlled comparative local anesthetic blocks. Among patients not using opioids (group I), the prevalence of facet joint pain was shown to be 33 percent in the cervical spine, 40 percent in the thoracic spine, and 18 percent in the lumbar spine, with false-positive results with a single lidocaine block of 53 percent, 33 percent, and 54 percent, respectively. Facet joint involvement in patients with opioid use ranged from 37 percent to 53 percent in the cervical spine, 13 percent to 67 percent in the thoracic spine, and 28 percent to 33 percent in the lumbar spine.

Overall, this evaluation demonstrated that current or prior opioid use is not associated with interference of the validity of controlled comparative local anesthetic blocks in diagnosing spinal facet joint-related pain.