Local Anesthetic Selection for Fingertip Laceration Repair
Primary Recommendation
Use lidocaine 1-2% with epinephrine (1:100,000 or 1:200,000) buffered with sodium bicarbonate for fingertip laceration repair. This combination provides optimal anesthesia duration, reduced injection pain, and is definitively safe for digital use 1, 2.
Standard Approach
First-Line Agent: Lidocaine with Epinephrine
Lidocaine with epinephrine is explicitly safe for digits, including fingers and toes, with Level A evidence from the American Academy of Dermatology showing no cases of necrosis reported 2.
Use epinephrine concentration of 1:100,000 or 1:200,000, which prolongs anesthesia duration by approximately 200% and provides effective vasoconstriction 1, 2.
Maximum safe dose is 7 mg/kg of lidocaine with epinephrine in adults (approximately 500 mg for a 70 kg patient) 1.
Pain Reduction Strategy
Buffer the lidocaine with sodium bicarbonate by mixing 8.4% sodium bicarbonate with lidocaine in ratios studied (typically 1:10 ratio), which decreases injection pain by 20-40% in approximately 2 out of 3 patients 1, 3.
Buffered lidocaine significantly reduces pain during infiltration (p=0.03) without compromising anesthetic effectiveness during suturing 3.
Inject slowly to further minimize discomfort, as rapid injection increases pain 1.
Alternative Agents for Specific Situations
For Patients with Lidocaine Allergy (Rare - Only 1% of Adverse Reactions)
Switch to an ester-type anesthetic (procaine or tetracaine) as cross-reaction between amide and ester types is rare 1, 4.
Consider 1% diphenhydramine injection for small lacerations, though it has slower onset (5 minutes vs 1 minute) and limited efficacy 1, 4.
Bacteriostatic saline (0.9% benzyl alcohol) with epinephrine may be less painful than diphenhydramine and serves as another alternative 1, 4.
Topical Options (Less Practical for Fingertip Lacerations)
LET gel (lidocaine 4%, epinephrine 0.1%, tetracaine 0.5%) can be applied for 30 minutes, though 19% of patients still require additional infiltrated anesthetic 5.
EMLA cream requires 60 minutes for full effectiveness, making it impractical for most emergency laceration repairs 4.
Dosing Specifics
Adult Dosing
- Maximum 7 mg/kg lidocaine with epinephrine (or 4.5 mg/kg without epinephrine) 1.
- For a fingertip laceration, typically 1-3 mL of 1% lidocaine with epinephrine is sufficient 1.
Pediatric Dosing
- Maximum 3-4.5 mg/kg lidocaine with epinephrine (or 1.5-2.0 mg/kg without epinephrine) 1.
- Use concentrations less than 2% (0.5-1.5%) in children under 3 years or weighing less than 30 lbs 6.
Critical Safety Considerations
Cardiovascular Disease
- Epinephrine in small amounts (1:100,000 to 1:200,000) is safe in patients with stable cardiovascular disease, including hypertension, ischemic heart disease, and arrhythmias 1.
- Consult cardiology if the patient's ability to safely undergo the procedure is uncertain 1.
Technique to Prevent Toxicity
- Aspirate before injection to avoid intravascular administration 1, 7.
- Use the lowest effective dose and concentration to minimize risk of local anesthetic systemic toxicity 1, 7.
- Monitor for early toxicity signs: perioral numbness, metallic taste, tinnitus, confusion, or seizures 7.
Common Pitfalls to Avoid
- Do not avoid epinephrine in digits based on outdated teaching—this is definitively safe and provides superior anesthesia 2.
- Do not use bupivacaine with bicarbonate buffering, as precipitation may occur and decrease efficacy 1.
- Do not exceed maximum dosing limits, especially when combining multiple local anesthetic techniques 1, 7.
- Do not use plain lidocaine when buffered lidocaine is available, as buffering significantly reduces injection pain without compromising effectiveness 1, 3.