Use of Lidocaine with Epinephrine in Toe Procedures
Lidocaine with epinephrine is safe and recommended for use in toe procedures. 1 This recommendation is supported by high-quality evidence from the American Academy of Dermatology guidelines, which explicitly states that the addition of epinephrine to local infiltration anesthesia is safe for use on the feet and digits.
Evidence Supporting Safety
The long-standing belief that epinephrine should not be used in digits (fingers and toes) has been debunked by modern evidence:
- The 2016 American Academy of Dermatology guidelines clearly recommend epinephrine use in digits, including toes 1
- No cases of necrosis have been reported in over a quarter of a million procedures using lidocaine with epinephrine in digits 2
- The historical concern about tissue necrosis was based on case reports from the early 1900s that did not involve lidocaine 2
Benefits of Using Epinephrine with Lidocaine
Adding epinephrine to lidocaine provides several clinical advantages:
- Prolongs anesthetic effect (by approximately 3.2 hours) 3
- Reduces bleeding during surgery (risk ratio of 0.35 compared to plain lidocaine) 3
- Slows mobilization of the anesthetic, reducing peak blood levels 1
- Creates a relatively bloodless operating field, which can reduce procedure duration 4
Practical Recommendations
When using lidocaine with epinephrine in toe procedures:
- Use the lowest effective concentration of epinephrine (typically 1:100,000 or 1:200,000) 5
- Consider buffering the anesthetic with sodium bicarbonate to decrease pain during infiltration 1, 5
- Be aware that epinephrine reduces local blood flow by approximately 42-69% but does not completely block perfusion 4
Special Considerations and Precautions
While generally safe, certain precautions should be observed:
- For patients with stable cardiac disease, lidocaine with epinephrine can be used, but consult with the patient's cardiologist if uncertain 1
- For pregnant patients, elective procedures requiring lidocaine with epinephrine should be postponed until after delivery 1
- In rare cases of epinephrine-induced vasospasm, phentolamine can be used as a rescue medication 6
- Patients with multiple comorbidities that may predispose to vasospasm (such as Raynaud's syndrome) may require closer monitoring 2, 6
Mechanism of Action
Epinephrine prolongs the duration of lidocaine anesthesia through a pharmacokinetic mechanism:
- It causes local vasoconstriction, which decreases local anesthetic clearance from the injection site 7
- This results in prolonged tissue concentration of the anesthetic agent 7
The evidence clearly supports that the historical prohibition against using epinephrine in digits was not based on sound scientific evidence. Modern clinical practice and research demonstrate that lidocaine with epinephrine can be safely and effectively used in toe procedures, providing significant clinical benefits without increasing the risk of tissue necrosis.