Evaluating two doses of intravenous lidocaine infusion for relief of nerve-related pain that persists after trauma or surgery.
A pilot randomised controlled trial of lidocaine for post-traumatic and post-surgical neuropathic pain: Does dose or patient profile modify the outcome?
Royal Brisbane and Women's Hospital
40 participants
Dec 6, 2022
Interventional
Conditions
Summary
Neuropathic pain (or nerve pain) is a type of pain that can affect people who have had a traumatic incident or surgery that causes damage to nerves. It occurs in bursts and is often severe and chronic. Pain relief can be difficult to achieve in people with this type of pain. Lidocaine is a local anaesthetic drug that can be given by intravenous drip in a hospital setting, to provide a period of relief from neuropathic pain. Pain is a unique experience for the individual person, blending a combination of body and mind factors. The response to intravenous lidocaine varies greatly from almost complete pain relief for months through to no relief or even feeling worse pain after the drip. We don’t know enough about the optimal dose or which people will get the best pain relief from intravenous lidocaine. The Tess Cramond Pain and Research Centre (TCPRC) is a specialised centre for people with chronic pain. Researchers at the TCPRC will compare two different doses of intravenous lidocaine and a placebo dose (saline without lidocaine) for people with neuropathic pain, to see which gives the best pain relief while minimising the risk of side effects over one week. This study also aims to provide more understanding about each individual person, with participants completing a series of questionnaires about their how their pains feel, expectations from the treatment, their thoughts, feelings and physical activity relative to their goals. Sensory assessments will also be measured, involving standardised hot, cold and pressure stimuli at the skin to determine how the person’s nerve sensitivity contributes to their neuropathic pain. The results of this important study will help to guide anaesthetist’s and specialists pain doctor’s decisions about the best dose of intravenous lidocaine to provide, and which patient characteristics of people with neuropathic pain are most likely to get the most effective and sustained pain relief. This will have potential to improve the quality and the efficiency of care provided at the Tess Cramond Pain and Research Centre and potentially at other treatment centres. The results of this study will also provide the foundation for a much larger study across many hospitals, to conclusively determine the dose of intravenous lidocaine and patient characteristics that achieve the best pain relief, to inform the standard for treating post-traumatic neuropathic pain in Australia and overseas.
Eligibility
Inclusion Criteria4
- Adults with a documented diagnosis of peripheral neuropathic pain (sensory changes affecting the region of the primary pain as well as qualities identified to be indicative of neuropathic pain in the current short form of the McGill Pain Questionnaire (SF-MPQ-2) and the painDETECT questionnaire.
- Pain for at least 6 weeks duration with moderate to high intensity (average pain at least 5 and worst pain at least 7 on the numerical rating scale) and localised to one side of the body.
- Pain not responsive to other forms of treatment or treatment side effects with oral agents
- Absence of pain affecting the opposite quadrant to the primary site of neuropathic pain. This criterion excludes whole-body pain presentations that are likely to have quite a different combination of dominant pain mechanisms and enables the opposite quadrant to be used as a pain-free remote site for quantitative sensory testing.
Exclusion Criteria15
- Inability to understand and respond to instructions and questions in English, or inability to write in English.
- A previous history of a intravenous lidocaine infusion while not under general anaesthetisia, currently receiving lidocaine or its oral analogues (mexiletine or flecainide). Previous intraoperative lidocaine infusion will be noted, but will not be an exclusion criterion.
- Contraindications or precautions for intravenous lidocaine infusion that are included in standard clinical screening for contraindications and precautions for lidocaine administration, as noted on the TGA Product and Consumer Medicine Information Licence for lidocaine:
- i) Arrhythmia such as atrial fibrillation, conduction blocks, pacemaker/automatic implantable cardioverter defibrillator, or use of anti-arrhythmic medication. A resting heart rate of under 50 BPM and over 100 BPM.
- ii) Moderate to severe cardiac failure, uncontrolled hyper (>170/100) or hypotension (<100/60), severe hepatic, renal, thyroid, diabetes, infections, or haematological conditions. As clinically indicated, the study team will order pathology tests to identify/exclude these conditions.
- iii) Seizure disorders that would present a safety risk during infusion or quantitative sensory testing.
- iv) Cognitive limitations or psychiatric disorders where the condition is unstable or limiting ability to attend to and to consistently report body perceptions or complete questionnaires (may include schizophrenia, somatization, or acute anxiety), which would contribute increased risk with lidocaine or application of quantitative sensory testing.
- v) Pregnancy or breastfeeding.
- vi) Allergies, interaction with current medications or abnormal lidocaine sensitivity.
- Health conditions that contraindicate quantitative sensory testing due to increased tissue vulnerability with pressure or thermal stimuli.
- Concomitant neurological conditions that limit peripheral nervous system function in the region of the primary post-trauma pain, or neurological conditions that affect the central nervous system (as moderate traumatic brain injury).
- Body weight >100 kg, as higher weight would require greater than the standard clinical practice maximum dosage of 500mg of lidocaine, to deliver 5mg/kg.
- An electrocardiograph recording will be made to examine for any alterations in trace that would contraindicate lidocaine infusion.
- i) This can include a previous ECG within the last 6 months
- ii) It can be ordered at the time of screening examination for review later (undertaken at a local facility or at the RBWH).
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Interventions
Intravenous lidocaine infusion, randomised to either 3 mg/kg, 5 mg/kg delivered in 30-60 min. The attending unblinded registrar will prepare the dose as informed, cross-checked and recorded by the pharmacist. The blinded doctor and nurse delivering the infusion will chart all information in relation to the delivery. Records from both the preparation and the delivery will be reviewed to confirm fidelity of the intervention when progressing to unblinded reporting of results.
Locations(1)
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ACTRN12622000538741