Background Low-dose lidocaine is a common diluent for analgesia following cervical interlaminar epidural steroid injection (CIESI). Concerns with this practice exist. A single-arm cohort reported that 20% of patients develop postprocedural upper extremity weakness when using lidocaine as a diluent. Furthermore, a high-cervical spinal block with unintended intrathecal or subdural administration is possible.
Objective Determine if low-dose lidocaine as a diluent during CIESI causes clinically meaningful (1) upper extremity weakness and (2) immediate pain relief when compared with saline.
Design Double-blinded randomized control trial.
Methods Patients with cervical radicular pain scheduled for CIESI were enrolled. Participants received lidocaine (CIESI-L) or saline (CIESI-S) as a diluent for the epidural injectate. Myotomal strength was measured with dynamometry before and between 20 and 30 min after CIESI. Pre-pain and post-pain scores were obtained. Primary and secondary outcomes were post-CIESI weakness of ≥20% (minimal clinically important difference (MCID)) in >1 myotome and ≥50% pain reduction on the numerical scale.
Results 120 participants (64 females (53%), mean age, 56 (SD 13.7) years) completed the study and were analyzed (CIESI-L n=60; CIESI-S n=60). There was no significant between-group difference in the proportion of participants with postprocedural weakness, CIESI-L 41.7% (95% CI, 29.8% to 54.5%), CIESL-S 50% (95% CI, 37.5% to 62.5%). Between-group comparison showed no significant difference in pain reduction, relative risk 1.53 (95% CI, 0.82 to 2.86).
Conclusion Low-dose lidocaine as a diluent in CIESI does not significantly increase the risk of post-CIESI myotomal weakness when compared with saline, but also does not substantially increase the likelihood of immediate, meaningful pain relief.
Trial registration details ClinicalTrials.gov (NCT03127137); December 26, 2017.
- neck pain
- pain management
- injections, spinal
- outcome assessment, health care
- treatment outcome
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Contributors ZD, RWK, and DW conceived and designed the study; ZD, SC, DB, and DW were involved in data acquisition; ZD, TB, RWK, MT, and DW were involved in analysis and/or interpretation of data; ZD, TB, and DW drafted the manuscript; ZD, TB, SC, RWK, DB, MT, and DW revised the manuscript critically for important intellectual content. All authors gave approval for the final manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests ZM and MD serve on the Board of Directors of the Spine Intervention Society.
Patient consent for publication Not required.
Ethics approval The study protocol was approved by the Northwestern University Institutional Review Board (IRB STU00204980).
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement All data relevant to the study are included in the article or uploaded as supplementary information. Data is available upon request.
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