Minimum and Maximum Dose of Local Anesthesia for Circumcision
For circumcision, the maximum safe dose of lidocaine without epinephrine is 4.5 mg/kg in adults and 1.5-2.0 mg/kg in children, while with epinephrine it increases to 7.0 mg/kg in adults and 3.0-4.5 mg/kg in children. 1, 2
Adult Dosing
- Maximum recommended dose of lidocaine without epinephrine: 4.5 mg/kg (not to exceed 300 mg total) 2
- Maximum recommended dose of lidocaine with epinephrine: 7.0 mg/kg 1, 3
- For multistage procedures like Mohs surgery, a maximum of 500 mg of lidocaine delivered over several hours is recommended, which can be applied to complex circumcision cases 1
Pediatric Dosing
- For children: maximum dose of lidocaine without epinephrine is 1.5-2.0 mg/kg 1
- For children: maximum dose of lidocaine with epinephrine is 3.0-4.5 mg/kg 1, 3
- Example: For a 5-year-old child weighing 50 lbs (22.7 kg), the maximum lidocaine dose should not exceed 75-100 mg 2
Minimum Effective Dose
- The minimum effective dose varies by technique, but clinical practice suggests using the lowest effective dose to minimize risk of toxicity 1
- For dorsal penile nerve block (DPNB), studies have shown efficacy with 0.7-1.0 mL of 1% lidocaine 4
- For jet injection technique (needle-free), as little as 0.9 mL of 2% lidocaine has been effective for adult circumcision 5
Administration Techniques
- Dorsal penile nerve block (DPNB) with lidocaine is more effective for pain control than topical anesthetics like EMLA cream 4
- For DPNB, inject slowly and aspirate before injection to avoid intravascular administration 1
- Topical anesthetics (EMLA cream) can be used but provide less effective pain control than DPNB 6, 7
Safety Considerations
- Steps to decrease risk of local anesthetic systemic toxicity:
- Avoid using lidocaine within 4 hours of other local anesthetic interventions 1, 8
- For patients with true lidocaine allergy, alternatives include ester-type local anesthetics, bacteriostatic normal saline, or 1% diphenhydramine 1
Special Considerations
- Adding epinephrine to lidocaine is safe for penile procedures and extends the duration of anesthesia 1, 3
- Epinephrine concentrations of 1:100,000 and 1:200,000 are commonly used in dermatologic surgery 1
- Buffering lidocaine with sodium bicarbonate (1:9 or 1:10 ratio) can decrease injection pain while maintaining effectiveness 3
Multimodal Approach
- Combined analgesia (DPNB plus non-pharmacological interventions like pacifiers) provides better pain control than single interventions for neonatal circumcision 6
- Sedation-only anesthesia can be effective for pediatric circumcision with fewer local complications than when combined with local infiltration 9
Always calculate dosage based on the patient's weight and use the lowest effective concentration and dose to minimize systemic toxicity risk 1, 2.