Recommended Dosage of Lignocaine for Local Anesthesia
The maximum safe dose of lignocaine for local anesthesia is 7 mg/kg with epinephrine (not exceeding 500 mg total) and 4.5 mg/kg without epinephrine (not exceeding 300 mg total) for normal healthy adults. 1
Maximum Dosage Guidelines by Administration Route
For Infiltration and Peripheral Nerve Blocks:
- Maximum dose with epinephrine: 7 mg/kg (not exceeding 500 mg total) 1
- Maximum dose without epinephrine: 4.5 mg/kg (not exceeding 300 mg total) 1
- For dilute solutions (0.4-0.5%), up to 500 mg plain lignocaine or 670 mg with adrenaline can be safely used 2
For Intravenous Regional Anesthesia:
For Bronchoscopy:
- Maximum total dose: 8.2 mg/kg (approximately 29 ml of 2% solution for a 70 kg patient) 4
- 2% lignocaine gel is preferred over spray for nasal anesthesia 4
For Intravenous Lidocaine Infusions:
- Loading dose: 1.5 mg/kg given over 10 minutes 4
- Maintenance infusion: 1.5 mg/kg/hour for no longer than 24 hours 4
- Calculate using ideal body weight rather than actual body weight 4, 3
Special Population Considerations
- Reduce doses by 30% in infants younger than 6 months 3
- Use lower doses in elderly patients and those with liver or cardiac impairment 4, 1
- For children over 3 years: Maximum dose should not exceed 3 mg/kg 1
- For patients weighing less than 40 kg: Intravenous lidocaine infusions should be avoided 4
Concentration Selection
- Lower concentrations (0.2-0.5%) allow for higher total doses to be administered safely 2
- Concentrated solutions (1-2%) should not be used for infiltration techniques 2
- For epidural anesthesia: 2-3 mL of the indicated concentration per dermatome 1
Important Safety Considerations
- Do not exceed the maximum recommended dose to avoid local anesthetic systemic toxicity 3, 5
- When using multiple local anesthetics concurrently, consider the additive effects 3
- Do not use intravenous lidocaine within 4 hours of other local anesthetic interventions 4
- Use epinephrine-containing solutions (typically 1:200,000) when larger volumes are required to reduce systemic absorption, unless contraindicated 1, 6
- Monitor for signs of toxicity, which correlate directly with total dose administered 1, 5
Common Pitfalls to Avoid
- Using actual body weight instead of ideal body weight in obese patients 4, 3
- Administering too rapidly, which increases risk of toxicity 4
- Not accounting for reduced clearance in patients with renal, hepatic, or cardiac disease 5
- Failing to adjust dosage in highly vascular areas where systemic absorption is increased 3
Despite recommendations to limit the dose to 400 mg, studies have shown that higher doses (up to 622 mg) during bronchoscopy did not result in toxic serum levels or adverse effects 7, 8. However, it's prudent to use the minimum effective dose whenever possible.