From the Guidelines
Lidocaine with epinephrine should generally not be used on toes, fingers, ears, nose, or penis due to the risk of tissue ischemia or necrosis. These areas are considered "end organs" with limited collateral blood supply, and the vasoconstricting effect of epinephrine could potentially compromise blood flow enough to cause tissue damage 1. Plain lidocaine without epinephrine is the preferred local anesthetic for these anatomical locations. This traditional teaching is summarized by the mnemonic "NOPE" (Nose, Organ of reproduction, Penis, Extremities) or "TEEN" (Toes, Ears, Extremities, Nose). While some recent research has questioned the absolute nature of this contraindication for fingers and toes, most clinicians still avoid using epinephrine in these areas out of an abundance of caution 1. If anesthesia is needed for a toe procedure, options include plain lidocaine (without epinephrine), bupivacaine, or other local anesthetics that don't contain vasoconstrictors. The maximum safe dose of plain lidocaine is 4.5 mg/kg (not to exceed 300 mg total) to avoid systemic toxicity 1.
Some key points to consider:
- The use of epinephrine in local anesthesia for toes, fingers, ears, nose, or penis is generally discouraged due to the risk of tissue ischemia or necrosis.
- Plain lidocaine without epinephrine is a safer alternative for these areas.
- The maximum safe dose of plain lidocaine is 4.5 mg/kg (not to exceed 300 mg total).
- Other local anesthetics, such as bupivacaine, may also be used as alternatives to lidocaine with epinephrine.
It's essential to weigh the potential benefits and risks of using lidocaine with epinephrine in these sensitive areas and consider alternative options to minimize the risk of complications.
From the Research
Use of Lidocaine with Epinephrine on Toes
- Lidocaine with epinephrine can be used on toes, as there is no significant evidence to suggest that it causes necrosis or ischemia in this area 2, 3.
- A review of literature found no cases of necrosis in a large number of reported accidents where EpiPen injections contained the same quantity of adrenaline as is found in 60 ml lidocaine with adrenaline 2.
- A study of 63 patients who received buffered 0.5% lidocaine with 1:200,000 epinephrine for Mohs micrographic surgery on fingers and toes found no cases of digital ischemia or necrosis 3.
- Another study found that the use of low-dose 1 percent lidocaine with epinephrine (1:100,000) in hand surgery has been well documented, and although rare, epinephrine-induced digital vasospasm can occur, it can be reversed with phentolamine 4.
Safety Precautions
- Care should be taken when using lidocaine with epinephrine in patients with infected toes or poor circulation 2.
- Patients with multiple comorbidities, such as circulatory disorders or diabetes, may be at higher risk of epinephrine-induced vasospasm, and prophylactic post-procedure phentolamine injection may be considered 4.
- The use of lidocaine with epinephrine in patients with ischemic heart disease has been found to be safe, with no significant disturbances in blood pressure or heart rhythm, and no myocardial ischemic changes 5.
Clinical Use
- Lidocaine with epinephrine can be used for various surgical procedures on toes, including Mohs micrographic surgery 3.
- The use of epinephrine-supplemented local anesthetics has been found to be safe for acral areas, such as the ear and nose, with no increase in complications 6.
- The addition of epinephrine to local anesthetics can provide a relatively bloodless operating field and longer effectiveness of local anesthesia 6.