Background: Intravenous (IV) sedation analgesia is often employed in patients with chronic
spinal pain undergoing diagnostic spinal injection procedures. The drugs used for intravenous
sedation analgesia produce varying degrees of sedation, amnesia, anxiolysis, muscle relaxation,
and analgesia. The very nature of these pharmacologic effects in altering the patient’s level of
consciousness, awareness, or response to a particular diagnostic stimulus invokes a sense of
uncertainty about the results or response obtained from the diagnostic procedure. There is an
ongoing controversy regarding the validity of controlled diagnostic blocks due to variability in
sensitivity, specificity, and accuracy. Moreover, there is no consensus with regards to the use
of sedation analgesic measures prior to controlled diagnostic blocks and their influence on the
accuracy and validity of a diagnosis.
Objective: To assess and update the clinically significant effects sedation analgesia procedures
have on the diagnostic accuracy and validity of interventional spinal techniques.
Methods: A comprehensive literature search using PubMed, EMBASE, and Cochrane Library
review databases up to September 2012 was performed. The search included systematic and
narrative review articles, prospective and retrospective studies, as well as cross-referencing of
bibliographies from notable primary and review articles and abstracts from scientific meetings
and peer-reviewed non-indexed journals. The search emphasized the effects of sedation
analgesia on diagnostic spinal interventions.
Conclusion: Based on a review of the available evidence, it appears that the administration
of mild to moderate sedation does not confound the results or diagnostic validity of spinal
injection procedures. Specifically, immediate pain relief after cervical and lumbar facet joint
controlled nerve blocks is not enhanced by IV sedation with midazolam or fentanyl. This is
especially true if stringent outcome criteria are employed, such as at least 75% pain relief
combined with an increase in range of motion for pain limited movements.
Key words: Conscious sedation, procedural sedation, intravenous sedation, analgesia,
hypnotics, sedatives, anxiolytics, opioids, chronic spinal pain, spinal injections, epidural
injections, controlled diagnostic nerve blocks, zygapophyseal or facet joint blocks, selective
nerve root blocks, provocation discography, sacroiliac joint injections, outcomes