Intravenous lidocaine has been used for decades to treat refractory neuropathic pain, however there have only been a modest number of studies with low participant numbers, inconsistent doses and variation in protocols to treat neuropathic pain post trauma or surgery.
The significance of this pilot randomised comparison of dose and placebo is that it will immediately provide best-available evidence to inform which clinical dose achieves the best combination of reduced pain intensity at one week post infusion, weighed against the risk of adverse events for this cohort. The duration of analgesia (recorded up to 12 weeks post infusion) and the effect size for each dose will inform power calculations for larger subsequent clinical trials. Exploratory survival analysis with data from quantitative sensory testing and questionnaires will give new insight into mechanisms of effect and patient profiles that respond best to intravenous lidocaine. The battery of outcomes recorded will provide the foundation for judicious selection of a smaller number of key variables for subsequent clinical trials and evidence to support a priori hypotheses to test the associations between patient profile and response to lidocaine infusion.
Dr Gunjeet Minhas, Tess Cramond Pain and Research Centre, Queensland.
The project was awarded $A19,902 through the ANZCA research grants program for 2022.