Systematic review of the role of sedation in diagnostic spinal interventional techniques.

There is ongoing controversy regarding the validity of controlled diagnostic blocks due to variability in sensitivity, specificity, and accuracy. Consequently, identification of false-positive rates, false-negative rates, and placebo responses is crucial. The reasons described for false-positive responses to diagnostic anesthetic blocks are many; however, sedation and psychological factors have been implied as causes. Further, there is no consensus with regards to sedation prior to controlled diagnostic blocks and their influence on the accuracy and validity of a diagnosis.