Recommended Dose of 1% Lidocaine for Suturing
For adults undergoing suturing, use no more than 4.5 mg/kg of plain 1% lidocaine (maximum 300 mg total) or 7.0 mg/kg with epinephrine (maximum 500 mg total) in a single treatment session 1, 2.
Practical Dosing Guidelines
Volume Calculations for 1% Lidocaine
Since 1% lidocaine contains 10 mg/mL:
- Plain lidocaine: Maximum ~30 mL for a 70 kg adult (4.5 mg/kg = 315 mg)
- Lidocaine with epinephrine: Maximum ~50 mL for a 70 kg adult (7.0 mg/kg = 490 mg)
Key Dosing Principles
Always use the lowest effective dose to minimize systemic toxicity risk 1. For simple laceration repair requiring suturing, you typically need only 1-5 mL of local infiltration around the wound edges, well below maximum limits.
Epinephrine significantly increases safe dosing limits by causing vasoconstriction that delays systemic absorption and prolongs anesthetic effect 1, 2. Use lidocaine with epinephrine 1:100,000 or 1:200,000 unless contraindicated (avoid on fingers, toes, penis, nose, ears, or in patients with severe cardiovascular disease) 3.
Safety Measures to Prevent Toxicity
The guidelines provide strong (Level A) evidence for toxicity prevention strategies 1:
- Aspirate before each injection to avoid intravascular administration
- Use incremental injections rather than bolus dosing
- Monitor the patient continuously for early signs of toxicity (perioral numbness, metallic taste, tinnitus, confusion, seizures)
- Wait at least 90 minutes before administering additional doses if continuous anesthesia is needed 2
Pediatric Dosing
For children, maximum doses are significantly lower 1, 2:
- Plain lidocaine: 1.5-2.0 mg/kg
- Lidocaine with epinephrine: 3.0-4.5 mg/kg
Pain Reduction Techniques
To minimize injection discomfort while maintaining efficacy:
- Buffer the lidocaine by mixing 1 mL of 8.4% sodium bicarbonate with 9-10 mL of 1% lidocaine with epinephrine immediately before use 1
- Inject slowly at a rate that minimizes tissue distension 1
- Warm the solution to approximately 40°C 1
- Use the smallest gauge needle practical (27-30 gauge)
Common Pitfalls
Do not exceed 300 mg plain lidocaine or 500 mg with epinephrine in adults regardless of patient weight for safety margin 2. The FDA labeling explicitly states these absolute maximum totals.
Avoid concentrated solutions for large-area infiltration—while 1% is standard for suturing, more dilute solutions (0.25-0.5%) allow larger volumes if needed for extensive repairs 4.
Do not use buffered solutions with epinephrine after prolonged storage—epinephrine degrades by 25% per week after buffering, reducing vasoconstrictor effect 1.