RT- IILiIA Version 1
Research type
Research Study
Full title
Randomised trial of intra-articular injection of lidocaine versus placebo in Inflammatory arthritis
IRAS ID
311106
Contact name
Bruce Kirkham
Contact email
Sponsor organisation
Guy' and St Thomas NHS Trust
Duration of Study in the UK
1 years, 0 months, 0 days
Research summary
To assess the contributions of peripheral neurons to joint pain, we plan to ask patients to rate the pain in their chosen joint before and after an injection of local anaesthetic (lidocaine) and steroid into their joint. Lidocaine blocks voltage-gated sodium channels (VGSCs) leading to a reversible block of action potential propagation in peripheral nerves. If the pain intensity reduces significantly following lidocaine injection, it suggests that the patients’ pain is due to peripheral sensitization, and that this is dampened by the local anaesthetic. If the pain intensity does not change or only falls slightly, then other centrally mediated factors are contributing to pain.
Before we can use this method, we need to ensure that reductions in pain score following joint injection are not due to placebo effect. Therefore, as part of this validation study patients will be randomised to receive either lidocaine plus steroid or, as a control, just steroid injection. The steroid is the main part of therapy as it relieves inflammation over a prolonged period, but is slower acting than lidocaine, and should not have an effect within ten minutes. Any improvement in ranking of pain within 10 minutes by patients receiving just steroid will therefore be due to placebo effect.
Our hypothesis is that there will be a significant difference in change in pain score before and after injection between the study group (lidocaine plus steroid) and control group (0.9% saline plus steroid). This will confirm the absence of a significant placebo effect and mean the differences in change in pain scores seen in the study group are due to differences in pain processing
REC name
Yorkshire & The Humber - Sheffield Research Ethics Committee
REC reference
22/YH/0051
Date of REC Opinion
24 Mar 2022
REC opinion
Further Information Favourable Opinion