Is lidocaine used for local anesthesia in small abscess drainage?

Lidocaine Local Anesthesia for Small Abscess Drainage

Yes, lidocaine local anesthesia is appropriate and recommended for small, simple abscesses in young, fit patients without systemic signs of sepsis, and can be performed safely in an outpatient setting. 1

When to Use Local Anesthesia for Abscess Drainage

Small, simple perianal abscesses may be treated under local anesthesia in young, fit patients without any signs of sepsis in an ambulatory setting. 1 This approach is supported by the World Society of Emergency Surgery (WSES) and American Association for the Surgery of Trauma (AAST) 2021 guidelines, which specifically endorse local anesthesia for appropriately selected patients. 1

Patient Selection Criteria

• Appropriate candidates: Young, immunocompetent patients with small, simple abscesses and no systemic signs of sepsis 1
• Requires general/regional anesthesia: Patients with sepsis, severe sepsis, septic shock, immunosuppression, diabetes mellitus, diffuse cellulitis, or complex abscess anatomy 1

Recommended Lidocaine Administration Technique

Standard Infiltration Approach

Use 1% lidocaine with epinephrine for local infiltration around the abscess, staying within maximum safe doses of 7.0 mg/kg with epinephrine or 4.5 mg/kg without epinephrine. 2 The addition of epinephrine provides hemostasis, prolongs anesthetic effect, and allows for higher safe dosing. 1

Pain Reduction Strategies

Buffer the lidocaine with sodium bicarbonate in a 1:10 ratio (1 mL of 8.4% sodium bicarbonate to 10 mL of 1% lidocaine with epinephrine) to significantly reduce injection pain. 1 This technique decreases pain by 20-40% compared to unbuffered lidocaine, with approximately 2 out of 3 patients reporting meaningful improvement. 1

Additional pain-reducing measures include: 1

• Slow infiltration rate
• Warming the solution to 40°C
• Using the smallest gauge needle practical
• Injecting through already anesthetized tissue when possible

Alternative Technique for Difficult Cases

For sacrococcygeal or particularly painful abscesses, consider aspirating the abscess first, then injecting the same volume of local anesthetic directly into the abscess cavity through the same needle. 3 This technique eliminates multiple painful infiltrations and requires less total anesthetic volume. 3

Critical Safety Considerations

Dosage Calculations

Always calculate the maximum allowable lidocaine dose in milligrams before starting the procedure to prevent systemic toxicity. 2 For a 70 kg adult:

• Without epinephrine: Maximum 315 mg (31.5 mL of 1% lidocaine) 2
• With epinephrine: Maximum 490 mg (49 mL of 1% lidocaine) 2

Toxicity Prevention

Aspirate before each injection to avoid intravascular administration, which dramatically increases toxicity risk. 2 Early signs of local anesthetic systemic toxicity (LAST) include: 2, 4

• Circumoral numbness
• Facial tingling
• Metallic taste
• Seizures
• Cardiovascular collapse

If LAST occurs, immediately administer 20% lipid emulsion: 100 mL bolus followed by 0.25 mL/kg/minute infusion. 4 This can be lifesaving in severe toxicity cases. 4

Topical Anesthesia Option

Topical lidocaine preparations (such as LMX4 cream) can be considered for abscess drainage and should be applied 30 minutes before the procedure. 1 However, research demonstrates that injectable lidocaine provides clinically similar analgesia to topical lidocaine/tetracaine patches during abscess incision and drainage. 5 The practical advantage of injectable lidocaine is immediate onset without the 30-60 minute wait required for topical agents. 1, 5

Common Pitfalls to Avoid

• Failing to calculate maximum dose beforehand: This leads to cumulative dosing errors, especially in larger abscesses requiring more anesthetic 2
• Using unbuffered lidocaine: This causes unnecessary pain during injection when buffering takes seconds and significantly improves patient comfort 1, 6
• Injecting into infected tissue: The acidic environment of abscesses reduces local anesthetic efficacy; consider the aspiration-injection technique or field block around the abscess instead 3
• Not having lipid emulsion readily available: LAST can progress rapidly from seizures to cardiac arrest within minutes 4