Introduction
Lidocaine is a local anesthetic that also has systemic analgesic effects. Systemic lidocaine is increasingly used off-label for the treatment of various pain conditions.
Mechanism of Action
Potential mechanisms of analgesic action are:
- Anti-inflammatory effects (most important mechanism)
- Inhibition of spontaneous impulse generation from injured peripheral nerves
- Suppression of polysynaptic reflexes in the spinal dorsal horn
- The analgesic effects are mediated through action on voltage-gated ion channels, including sodium, potassium, and calcium channels, and ligand-gated channels, including N-methyl-d-aspartic acid (NMDA) receptors, in the central nervous system
- Additionally, lidocaine targets G-protein-coupled receptors
- Continuous infusions reduce surgical as well as nonsurgical acute pain such as renal colic, critical limb ischemia, acute migraine, and radicular lower back pain.
- Short lidocaine infusions can achieve longer lasting symptom reduction in chronic pain conditions such as neuropathic pain and cancer pain
- Lidocaine has been shown to be a gastrointestinal pro-peristaltic drug
- A preventive analgesic effect has been suggested
Indications
- Analgesia following surgery
- Renal colic
- Critical limb ischemia
- Acute migraine
- Radicular lower back pain
- Herpetic neuropathy
- Complex Regional Pain Syndrome
- Fibromyalgia
- Chronic Neuropathic Pain
- Refractory Cancer Pain
Monitor for side effects or signs of Local Anesthetic Systemic Toxicity (LAST).
Mild side effects: Close monitoring is required, but discontinuation of infusion may or may not be indicated:
- Perioral numbness
- Metallic taste
- Dizziness
- Tinnitus
Moderate side effects: If the following symptoms occur, RNs immediately stop the infusion, contact provider, and activate code blue or rapid response depending on severity of patient’s condition:
- Severe dizziness
- Nausea, vomiting
- Decreased hearing
- Slurred speech
- Sedation
- Tremors
- Decrease in blood pressure >30 mmHg or pulse<50 bpm
- Altered mental status
Severe and late signs: If these occur, the infusion is stopped and code blue activated:
- Twitching
- Convulsions
- Loss of consciousness
- Cardiac arrythmias
- Cardiovascular collapse
LAST treatment is based on ASRA guidelines: https://www.asra.com/docs/default-source/guidelines-articles/local-anesthetic-systemic-toxicity-rgb.pdf?sfvrsn=33b348e_2
Contraindications
- Sensitivity or allergy to local anesthetics
- Concurrent use of regional anesthesia (peripheral nerve infusions, nerve blocks, epidural anesthesia, Exparel (liposomal bupivacaine), oral lidocaine (mexilitine), or single shot regional technique in the last 4-8 hours.
- Cardiac conduction abnormalities (Adams-Stokes syndrome, Wolff-Parkinson-White (WPW) syndrome, 2nd or 3rd degree heart blocks (unless patient has a pacemaker) or other dysrhythmia
- Severe heart failure (ejection fraction less than 20%),
- Severe hepatic (bilirubin greater than 1.46 mg/dl)
- Renal impairment (GFR less than 30 ml/min or ESRD)
- Seizure disorder
- Acute porphyria
Eipe, N et al. Intravenous lidocaine for acute pain: an evidence-based clinical update. BJA Education 2016 Volume 16, Issue 9, 292 - 298
De Oliveira, K., Eipe, N. Intravenous Lidocaine for Acute Pain: A Single-Institution Retrospective Study. Drugs - Real World Outcomes 7, 205–212 (2020)
Challapalli V, et al. Cochrane Database of Systematic Reviews 2005, Issue 4. Art. No.: CD003345.
Lee JT, et al. Lidocaine for Cancer Pain in Adults: A Systematic Review and Meta-Analysis. J Palliat Med. 2019 Mar;22(3):326-334.
ASRA Pain Medicine Update. (2020). Checklist for Treatment of Local Anesthetic Systemic Toxicity (LAST). https://www.asra.com/news-publications/asra-updates/blog-landing/guidelines/2020/11/01/checklist-for-treatment-of-local-anesthetic-systemic-toxicity