Safe Dosage of Lidocaine for Incision and Drainage of Abscess
For incision and drainage of an abscess, the maximum safe dose of lidocaine without epinephrine is 4.5 mg/kg (not exceeding 300 mg total) in adults and 1.5-2.0 mg/kg in children; with epinephrine, the maximum safe dose increases to 7.0 mg/kg in adults and 3.0-4.5 mg/kg in children. 1, 2
Adult Dosing Guidelines
- Calculate dosage using ideal body weight (IBW), which can be determined by: Men: IBW = height in cm - 100; Women: IBW = height in cm - 105 3
- For adults undergoing I&D procedures, the maximum recommended dose of lidocaine without epinephrine should not exceed 4.5 mg/kg of body weight, with a general recommendation that the total dose does not exceed 300 mg 2
- When using lidocaine with epinephrine, the maximum safe dose increases to 7.0 mg/kg in adults 1
- For complex or prolonged procedures, a maximum of 500 mg of lidocaine delivered over several hours is recommended 1
Pediatric Dosing Guidelines
- For children over 3 years of age with normal body development, the maximum dose of lidocaine without epinephrine is 1.5-2.0 mg/kg 1, 2
- With epinephrine, the maximum dose increases to 3.0-4.5 mg/kg in children 1
- For example, in a 5-year-old child weighing 50 lbs (22.7 kg), the dose of lidocaine should not exceed 75-100 mg 2
- Do not use lidocaine in patients weighing less than 40 kg without careful consideration 3
Administration Techniques for I&D
- Use the lowest effective concentration and dose to guard against systemic toxicity 2
- Inject slowly and with aspiration before injection to avoid intravascular administration 1
- For abscess I&D, consider needle aspiration of the abscess followed by injection of local anesthetic into the abscess cavity via the same needle, which can reduce pain and minimize the volume of anesthetic required 4
- Standard injectable lidocaine provides similar analgesia compared to transdermal lidocaine/tetracaine patches for I&D procedures 5
Safety Considerations
- Be vigilant for signs of local anesthetic toxicity: Early signs include tingling of tongue/lips, light-headedness, tinnitus, slurred speech; Progressive signs include muscle twitching, loss of consciousness, respiratory arrest 3, 6
- Avoid concurrent use with other local anesthetics: Do not start lidocaine within 4 hours of any nerve or fascial plane block or other local anesthetic interventions 3, 7
- Use incremental injections and aspirate before each injection to decrease risk of local anesthetic systemic toxicity 1
- Overdose of lidocaine can lead to serious complications including cardiac toxicity and arrest, which may require treatment with lipid emulsion therapy 6
- A documented case of cardiac arrest occurred after administration of 50 mL of 2% lidocaine (1000 mg) for I&D of a labial abscess, far exceeding the recommended maximum dose 6
Special Considerations
- Adding epinephrine to lidocaine extends the duration of anesthesia and allows for higher maximum doses 1
- Epinephrine concentrations of 1:100,000 and 1:200,000 are commonly used in dermatologic surgery 1
- Buffering lidocaine with sodium bicarbonate can decrease injection pain, though studies specific to I&D procedures have not shown significant benefits 1, 8
- For patients with true lidocaine allergy, alternatives include ester-type local anesthetics, bacteriostatic normal saline, or 1% diphenhydramine 1
- Intranasal fentanyl as an adjunct to local lidocaine infiltration has not shown substantial improvement in pain control during I&D procedures 9
Practical Application
For a 70 kg adult requiring I&D without epinephrine:
- Maximum dose = 4.5 mg/kg × 70 kg = 315 mg (limited to 300 mg)
- Using 1% lidocaine (10 mg/mL): Maximum volume = 30 mL
- Using 2% lidocaine (20 mg/mL): Maximum volume = 15 mL 2
For a 70 kg adult requiring I&D with epinephrine:
- Maximum dose = 7.0 mg/kg × 70 kg = 490 mg
- Using 1% lidocaine with epinephrine (10 mg/mL): Maximum volume = 49 mL
- Using 2% lidocaine with epinephrine (20 mg/mL): Maximum volume = 24.5 mL 1