Where can lidocaine with epinephrine be safely used?

Lidocaine with Epinephrine: Safe Anatomic Locations

Lidocaine with epinephrine can be safely used on all body sites including the ears, nose, hands, feet, and digits—the traditional prohibition against use in "end-artery" territories has been definitively refuted by extensive evidence. 1

Recommended Safe Sites (Strength of Recommendation: A, Level I-II Evidence)

The American Academy of Dermatology guidelines explicitly state that the addition of epinephrine to local infiltration anesthesia is safe and recommended for use on the ear, nose, hand, feet, and digits. 1 This represents the highest level of evidence-based recommendation, directly contradicting the outdated dogma about avoiding epinephrine in "end-artery" territories. 1

Evidence Supporting Safety in Previously Prohibited Sites

• Digits, hands, and feet: Multiple systematic reviews and randomized controlled trials found no cases of necrosis when epinephrine was added to local anesthesia in these locations 1, 2
• The use of epinephrine resulted in less need for tourniquet, faster onset, and longer duration of anesthesia 1
• Ear and nose: Addition of epinephrine to tumescent local anesthesia for ear and nose reconstruction resulted in no anesthesia-related complications and led to decreased operative time and reduced need for electrocautery hemostasis 1, 3
• A comprehensive review of 1,409 cases using lidocaine with epinephrine in the pinna and nose recorded zero ischemic complications 3

Historical Context of the Prohibition

The traditional prohibition was based on 48 cases of digital gangrene reported from 1880-1966, but only 21 involved epinephrine, and 17 of those used unknown concentrations based on manual dilution 4. Multiple concurrent conditions (hot soaks, tight tourniquets, infection) existed in these cases, making causation unclear 4. There have been no case reports of digital gangrene using commercial lidocaine with epinephrine since its introduction in 1948. 4

Additional Safe Sites

Penis: The addition of epinephrine to local infiltration anesthesia may be considered for use during procedures on the penis (Strength B, Level II evidence) 1. A retrospective study of penile ring blocks during circumcision observed no anesthetic-related complications 1.

Special Populations

Pregnant Women

• Local infiltrative anesthesia with epinephrine may be used in small amounts in pregnant women 1
• Elective procedures requiring lidocaine with epinephrine should be postponed until after delivery 1
• Procedures of urgent medical necessity should be delayed until the second trimester when possible 1
• When used in small amounts for dermatologic surgery, local vasoconstriction limits maternal blood levels and placental transfer of lidocaine 1

Patients with Cardiac Disease

• Local infiltrative anesthesia with epinephrine may be administered to patients with stable cardiac disease (Strength B, Level I-II evidence) 1
• If uncertain of a patient's ability to tolerate epinephrine, consult with the patient's cardiologist 1

Maximum Safe Doses

Adults

• No more than 7.0 mg/kg of lidocaine with epinephrine should be administered in a single treatment 1
• For comparison, plain lidocaine without epinephrine is limited to 4.5 mg/kg 1, 5

Children

• No more than 3.0-4.5 mg/kg of lidocaine with epinephrine should be administered in a single treatment 1
• For comparison, plain lidocaine is limited to 1.5-2.0 mg/kg in children 1

Optimal Concentration

Use the lowest effective concentration of epinephrine to provide pain control and vasoconstriction (Strength B, Level II-III evidence) 1. Concentrations between 1:50,000 and 1:400,000 are equally effective and provide superior vasoconstriction compared with more dilute solutions 6. If epinephrine is further diluted, its onset and duration of action are compromised 6.

Important Contraindications and Precautions

Absolute Contraindication

Solutions containing epinephrine or other vasoconstrictors should not be used for intravenous regional anesthesia 5

Relative Contraindications and Cautions

• Use cautiously in areas with compromised blood supply or peripheral vascular disease 5
• Patients with hypertensive vascular disease may exhibit exaggerated vasoconstrictor response 5
• Avoid in patients on monoamine oxidase inhibitors or tricyclic antidepressants due to risk of severe, prolonged hypertension 5
• Use with caution during or following potent general anesthetic agents due to risk of cardiac arrhythmias 5

Common Pitfall to Avoid

The most critical pitfall is continuing to avoid epinephrine in digits, ears, and nose based on outdated teaching. This deprives patients of the benefits of prolonged anesthesia, improved hemostasis, and reduced systemic toxicity risk 1, 2. The evidence overwhelmingly supports safety when using commercial preparations of lidocaine with epinephrine at appropriate concentrations 4.