Intravenous lidocaine use during general anesthesia induction : benefits and considerations

Lidocaine, a widely used local anesthetic, has gained attention for its systemic benefits when administered intravenously (IV) during the induction of general anesthesia. Its analgesic, anti-inflammatory and opioid-sparing properties make it an attractive adjunct in multimodal anesthesia strategies. However, despite its reported advantages, clinical experiences, including my own, suggest that its use is not without risks. Several patients have reported symptoms resembling local anesthetic systemic toxicity (LAST), leading me to reconsider its routine administration. This article explores the pharmacological effects, benefits, potential risks and my evolving perspective on its clinical use.

Pharmacodynamics of intravenous lidocaine

Lidocaine primarily acts by blocking voltage-gated sodium channels, which inhibits nerve impulse transmission. When administered intravenously, it exerts systemic effects beyond local anesthesia, including :

• Analgesia : Modulation of nociceptive pathways in the central nervous system.

• Anti-inflammatory properties : Suppression of cytokine release and inflammatory responses.

• Antihyperalgesic effects : Reduction in central sensitization, helping to control postoperative pain.

• Cardiac stabilization : Anti-arrhythmic effects that may benefit certain patient populations.

1. Reported benefits during anesthesia induction

1.1. Reduction of propofol-induced injection pain

Propofol, a common induction agent, is associated with injection pain. Pre-administration of IV lidocaine has been shown to alleviate this discomfort by stabilizing vascular endothelium and modulating pain perception.

1.2. Hemodynamic stability

Lidocaine can blunt the sympathetic response to laryngoscopy and endotracheal intubation, reducing hypertensive and tachycardic surges, particularly in patients with cardiovascular risk factors.

1.3. Opioid-sparing effects

By modulating nociceptive transmission, IV lidocaine reduces intraoperative opioid requirements, potentially minimizing opioid-related side effects such as respiratory depression and postoperative nausea.

1.4. Reduction in postoperative pain and hyperalgesia

IV lidocaine has been associated with prolonged postoperative analgesia by attenuating central sensitization, leading to improved patient comfort and faster recovery.

1.5. Anti-inflammatory and neuroprotective effects

Some studies suggest that IV lidocaine reduces systemic inflammation and oxidative stress, potentially improving outcomes in major surgeries.

2. Clinical concerns and personal experience with side effects

Despite these advantages, I have personally discontinued the routine use of IV lidocaine in anesthesia induction due to multiple reports from patients describing symptoms suggestive of mild local anesthetic systemic toxicity (LAST). These included:

• Tinnitus

• Visual disturbances (blurred vision, difficulty focusing)

• Metallic taste in the mouth

Although these symptoms were transient and did not progress to severe toxicity (such as seizures or cardiac arhythmias), their frequency raised concerns regarding patient safety and comfort. The experience prompted a reassessment of the risk-benefit balance of IV lidocaine in my practice.

2.1. Possible explanations for these symptoms

• Dose-related effects : Even within commonly recommended doses (1–1.5 mg/kg IV bolus), lidocaine plasma levels may vary among patients, particularly in those with altered metabolism (e.g., liver dysfunction, elderly patients).

• Rapid administration : Bolus injection speed may influence peak plasma concentration, potentially leading to transient toxicity symptoms.

• Individual sensitivity : Some patients may be more susceptible to lidocaine-related adverse effects, even at standard doses.

2.2. Reflections on the changing perspective of IV lidocaine Use

While the literature supports the benefits of IV lidocaine in certain surgical settings, real-world clinical experience underscores the importance of individualized patient responses. The occurrence of symptoms mimicking mild LAST, even without progressing to severe toxicity, is concerning. Given that the primary goal of anesthesia is to ensure patient comfort and safety, I have opted to remove IV lidocaine from my routine induction protocol, favoring alternative strategies for analgesia and hemodynamic control.

2.3. Alternative approaches

• For propofol injection pain : Mixing lidocaine with propofol (rather than administering it separately IV) or using a larger vein for injection.

• For opioid-sparing analgesia : Other adjuncts like ketamine, dexmedetomidine or regional anesthesia techniques may provide similar benefits without the risk of systemic toxicity.

3. Conclusion

Intravenous lidocaine remains a valuable tool in anesthesia, with well-documented benefits including analgesia, opioid reduction and hemodynamic stability. However, clinical experience has highlighted its potential for causing transient but distressing symptoms in some patients. This has led me to reconsider its routine use in my practice. While IV lidocaine may still have a place in selected patients, careful patient selection, dosing considerations and alternative strategies should be explored to optimize perioperative care.

4. References

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2. Kranke P, Jokinen J, Pace NL, et al. "Continuous intravenous perioperative lidocaine infusion for postoperative pain and recovery." Cochrane Database Syst Rev. 2015;2015(7):CD009642.

3. Dunn LK, Durieux ME, Nemergut EC. "Non-opioid analgesics: Novel approaches to perioperative analgesia for major spine surgery." Anesthesiology. 2018;128(3):591-613.

4. Martin F, Cherif K, Gentili M, et al. "Lidocaine and ketamine reduce morphine consumption after laparoscopic nephrectomy." Eur J Anaesthesiol. 2008;25(4):307-314.

5. McCarthy GC, Megalla SA, Habib AS. "Impact of intravenous lidocaine infusion on postoperative analgesia and recovery: A systematic review and meta-analysis." J Clin Anesth. 2010;22(3):233-239.

6. Weinberg GL. "Lipid rescue resuscitation from local anesthetic systemic toxicity." Reg Anesth Pain Med. 2010;35(2):140-147.