Disclaimer: This article is intended solely for informational and educational purposes only. It does not constitute medical advice.

Lidocaine is a widely used local anesthetic that is often administered topically or through injection to numb a target region. When administered intravenously, lidocaine produces analgesic, anti-inflammatory, and anti-hyperalgesic effects and has been investigated as an adjunct for reducing perioperative opioid requirements. Intravenous lidocaine may be used as part of multimodal analgesia, particularly during and after abdominal and other major surgical procedures. It has also been studied for its potential effects on postoperative nausea and vomiting, ileus, and recovery following surgery. Although clinical protocols vary, systemic lidocaine is generally administered as a weight-based bolus followed by a continuous infusion, with dosing adjusted according to patient factors and institutional protocols. 

A well-established perioperative application of intravenous lidocaine is analgesia. By reducing neuronal excitability and modulating nociceptive signaling, lidocaine may decrease postoperative pain and opioid consumption in selected surgical populations. Benefits appear to be most consistent in abdominal surgery, although evidence across surgical specialties is heterogeneous. Lidocaine may be particularly useful when an opioid-sparing strategy is desirable, such as in patients at increased risk for opioid-related respiratory depression or those undergoing procedures associated with substantial postoperative pain. Systemic lidocaine has also been investigated as an adjunct to enhanced recovery pathways because of its potential effects on gastrointestinal function and postoperative recovery. 

Systemic lidocaine has additional uses in the perioperative setting. Intravenous administration can suppress ventricular arrhythmias and is an established antiarrhythmic therapy for selected ventricular dysrhythmias. It may also attenuate the hemodynamic response to laryngoscopy and tracheal intubation when administered shortly before airway manipulation. Lidocaine has been studied for reducing bronchospasm and airway reactivity, although its routine use for this purpose is not universally supported. In some settings, intravenous lidocaine is also used to blunt coughing during emergence and extubation. 

Despite these potential benefits, systemic lidocaine carries important toxicity risks because the therapeutic and toxic concentrations are relatively close. Central nervous system manifestations are often the earliest signs of local anesthetic systemic toxicity and may include circumoral numbness, metallic taste, tinnitus, dizziness, agitation, confusion, and perioral or extremity paresthesias. With increasing plasma concentrations, seizures, central nervous system depression, respiratory depression, and coma may occur. Cardiovascular toxicity can include hypotension, bradycardia, conduction abnormalities, ventricular arrhythmias, and cardiovascular collapse. Although lidocaine is generally less cardiotoxic than several other local anesthetics, serious toxicity remains possible, particularly following excessive dosing or impaired drug clearance. 

Risk is increased in patients with hepatic dysfunction, low cardiac output, advanced age, or conditions associated with reduced protein binding or altered pharmacokinetics. Concomitant administration of other local anesthetics can further increase systemic exposure and toxicity. Continuous infusions should therefore be administered using standardized dosing protocols, with careful attention to cumulative dose and duration of therapy. Clinicians should also recognize that signs of toxicity may be subtle, particularly in patients receiving general anesthesia or sedation. 

Systemic lidocaine can be a useful component of multimodal perioperative care when appropriately selected and dosed. Its potential to reduce pain and opioid exposure, while possibly improving aspects of postoperative recovery, makes it an attractive adjunct in selected patients. However, these benefits must be weighed against the possibility of neurologic and cardiovascular toxicity. Appropriate patient selection, weight-based dosing, avoidance of excessive cumulative exposure, and vigilance for early manifestations of toxicity are essential when using intravenous lidocaine in the perioperative setting. 

References 

1. Weibel S, Jelting Y, Pace NL, et al. Continuous intravenous perioperative lidocaine infusion for postoperative pain and recovery in adults. Cochrane Database Syst Rev. 2018;6(6):CD009642. DOI: 10.1002/14651858.CD009642.pub3 

2. Kranke P, Jokinen J, Pace NL, et al. Continuous intravenous perioperative lidocaine infusion for postoperative pain and recovery. Cochrane Database Syst Rev. 2015;(7):CD009642. DOI: 10.1002/14651858.CD009642.pub3 

3. Gitman M, Barrington MJ. Local anesthetic systemic toxicity: a review of recent case reports and registries. Reg Anesth Pain Med. 2018;43(2):124-130. DOI: 10.1097/AAP.0000000000000721 

4. El-Boghdadly K, Pawa A, Chin KJ. Local anesthetic systemic toxicity: current perspectives. Local Reg Anesth. 2018;11:35-44. DOI: 10.2147/LRA.S154512