Intravenous Lidocaine Administration Guidelines
Dosing Guidelines
- The American Society of Anesthesiologists recommends calculating the dose using ideal body weight rather than actual body weight, especially important in obese patients 1, 2, 3
- The initial loading dose should not exceed 1.5 mg/kg, administered as an infusion over 10 minutes (not as a bolus) 1, 2, 3
- Maintenance infusion should not exceed 1.5 mg/kg/hour 1, 2, 3
- Maximum infusion duration should be limited to 24 hours 1, 2, 3
- For any patient, regardless of weight, do not exceed 120 mg/hour 1, 2, 4
- Do not use intravenous lidocaine in patients weighing less than 40 kg 1, 2, 4
Safety Considerations
- Intravenous lidocaine should be considered a "high-risk" medication requiring appropriate monitoring 1, 2
- Continuous ECG monitoring, pulse oximetry, and regular blood pressure measurements are recommended during administration 3
- The initial loading dose should be administered with an anesthesiologist present 3
- Lidocaine infusion should be delivered through a separate, dedicated cannula 3
- Do not administer intravenous lidocaine within 4 hours of other local anesthetic interventions (e.g., nerve blocks) 1, 2, 3
- Do not perform nerve blocks until 4 hours after discontinuing an intravenous lidocaine infusion 1, 2, 3
- Lipid emulsion 20% should be readily available wherever intravenous lidocaine is used to treat potential toxicity 1, 2
Clinical Applications
- Intravenous lidocaine has shown efficacy for opioid-refractory cancer pain 5
- It may be particularly useful for neuropathic pain conditions 5
- For postoperative pain management, intravenous lidocaine should be part of a multimodal approach 1, 2
Monitoring and Precautions
- Patients receiving intravenous lidocaine outside the operating room/recovery area should ideally be managed in a monitored setting (high dependency unit) 4
- Be vigilant for signs of local anesthetic systemic toxicity, which can include perioral numbness, tinnitus, metallic taste, visual disturbances, confusion, seizures, and cardiovascular collapse 3
- Hospital medication governance committee approval should be obtained before implementing intravenous lidocaine protocols 1, 2
- Informed consent should be obtained from patients when possible 1, 2
IV Lidocaine Pharmacokinetics and Safety
Pharmacokinetic Considerations
- Lidocaine exhibits time-dependent pharmacokinetics, with a half-life of 100 minutes for infusions less than 12 hours, but increases to 3.22 hours after 24 hours, according to the Anaesthesia guideline 6
- After 24 hours, infusion rate should be reduced by approximately 50% even in patients without cardiac or hepatic failure, as recommended by the Anaesthesia guideline 6
- Toxic plasma concentrations occur at 9-10 µg/mL, as reported in the Anaesthesia journal 6
Factors Increasing Toxicity Risk
- Acidemia increases free drug by enhancing dissociation from plasma proteins, increasing the risk of toxicity, as noted in the Anaesthesia journal 6
- Hypoalbuminemia and protein depletion increase free plasma drug concentration, contributing to toxicity risk, according to the Anaesthesia guideline 6
- Low skeletal muscle mass reduces drug reservoir capacity, increasing toxicity risk, as reported in the Anaesthesia journal 6
- High BMI patients may have inadvertently higher plasma concentrations when actual rather than ideal body weight is used for dosing, as noted in the Anaesthesia journal 6
- Beta-blockers reduce lidocaine metabolism, increasing toxicity risk, as reported in the Anaesthesia journal 6
- Amiodarone decreases clearance, particularly problematic with prolonged infusions, according to the Anaesthesia guideline 6
- Cytochrome P450 inducers and inhibitors affect metabolism, contributing to toxicity risk, as noted in the Anaesthesia journal 6
Guidelines for Safe Intravenous Lidocaine Use During Intra‑operative Neuromonitoring
Dose Calculation
Use ideal body weight (IBW) rather than actual weight, especially in obese patients: IBW = height (cm) − 100 kg for men and height (cm) − 105 kg for women. 7
Do not administer intravenous lidocaine to patients whose total body weight is < 40 kg. 8
Dosing Regimen
Loading dose: Maximum 1.5 mg · kg⁻¹ (IBW) given as a 10‑minute infusion; rapid bolus administration is prohibited because it raises toxicity risk. 8
Maintenance infusion: 1.5 mg · kg⁻¹ h⁻¹ (IBW). 8
Maximum duration: Do not exceed 24 hours; if continuation beyond 24 h is required, reduce the infusion rate to 50 % of the original dose because lidocaine’s half‑life lengthens from ≈ 100 min to ≈ 3.2 h after prolonged exposure. 8
Monitoring Requirements
During the loading infusion: Continuous ECG, pulse‑oximetry, and non‑invasive blood pressure measured every 5 minutes throughout the infusion and for the first 15 minutes afterward. 8
Personnel: An anesthesiologist must be present in the operating room for the entire loading phase. 8
Post‑operative care (outside the OR): Patients should be cared for in an intermediate‑care unit with vital‑sign observations at least every 15 minutes during the first hour, then at least hourly thereafter. 8
Safety Intervals with Other Local Anesthetic Techniques
Do not start intravenous lidocaine within 4 hours after any peripheral nerve block, fascial‑plane block, or laparoscopic port infiltration. 7
Do not perform peripheral nerve or fascial‑plane blocks until 4 hours after the completion of an intravenous lidocaine infusion. 7
Do not administer bolus doses of local anesthetic through wound‑catheter or epidural catheters until 4 hours after stopping the lidocaine infusion. 7
Continuous infusions through wound‑catheter or epidural systems may be initiated 30 minutes after the lidocaine infusion is discontinued. [7][8]
Remove 5 % topical lidocaine patches before beginning the intravenous infusion. [7][8]
Recognition of Lidocaine Toxicity
Early neurologic signs (plasma 5–10 µg mL⁻¹): perioral numbness, facial tingling, tongue/lip tingling, tinnitus, dizziness, light‑headedness, and slurred speech. 8
Severe toxicity (plasma > 10 µg mL⁻¹): loss of consciousness, seizures, respiratory arrest, cardiac arrhythmias, myocardial depression, and ventricular fibrillation. 8
Relative Contraindications
- Pre‑existing cardiac disease or electrolyte disturbances. 7
- History of seizures or other seizure disorders. 7
- Renal impairment or hepatic insufficiency (advanced hepatic disease is an absolute contraindication). 7
- Pregnancy or lactation. 7
- Pre‑existing neurological disorders. 7
Equipment and Administration
- Use a dedicated, locked infusion pump with a fixed upper‑rate limit to deliver lidocaine. 8
- Infuse through a separate, dedicated line that includes a saline (0.9 %) flush of 10 mL h⁻¹ to maintain line patency. 8
- The infusion line must incorporate a one‑way valve to prevent retrograde flow into other concurrent infusions. 8
- Employ a standardized, commercially prepared lidocaine concentration throughout the institution. 8
Informed Consent
- Obtain explicit informed consent when feasible, clearly outlining the limited risks and benefits of off‑label intravenous lidocaine use, in accordance with standard institutional guidelines for off‑label medication administration. 7