What is TLA (Tumescent Local Anesthesia) and how is it administered?

Tumescent Local Anesthesia (TLA): Definition and Administration

TLA is a specialized regional anesthetic technique involving subcutaneous infiltration of large volumes of highly diluted local anesthetic (typically lidocaine 0.05-0.1% with epinephrine) that provides prolonged anesthesia and hemostasis for dermatologic and surgical procedures. 1

What is TLA?

Core Technique:

• TLA involves infiltrating large volumes of diluted local anesthetic solution into subcutaneous tissue to create tissue turgor ("tumescence") 2, 3
• The standard solution contains lidocaine or prilocaine in very dilute concentrations (0.05-0.1%) combined with epinephrine 1
• This differs fundamentally from standard local infiltration, which uses smaller volumes of more concentrated anesthetic 1

Primary Applications:

• Office-based liposuction (most common indication) 1, 4
• Varicose vein surgery and endovenous procedures 2, 3
• Extensive dermatologic procedures requiring large-area anesthesia 1
• Plastic and cosmetic surgical procedures 3, 5

How TLA is Administered

Solution Preparation

Standard Formulation:

• Lidocaine with epinephrine is the recommended anesthetic for tumescent anesthesia 1
• Typical concentration: 0.05-0.1% lidocaine (500-1000 mg/L) with epinephrine 1:1,000 1, 5
• Alternative: Prilocaine may be used, though it carries methemoglobinemia risk at high doses 1, 5

Dosing Parameters

Maximum Safe Doses:

• For liposuction: Up to 55 mg/kg of lidocaine with epinephrine has Level A evidence for safety in patients weighing 43.6-81.8 kg 1
• For non-liposuction procedures: Maximum should not exceed 28 mg/kg of lidocaine with epinephrine 4
• These doses far exceed standard infiltrative anesthesia limits (7 mg/kg with epinephrine) due to slow absorption from subcutaneous tissue 1

Administration Technique

Key Technical Steps:

• Use warm anesthetic solution (40°C) to decrease patient discomfort during infiltration 1
• Employ slow infiltration rate to minimize pain during administration 1
• Infiltrate solution into subcutaneous tissue using specialized cannulas or needles 2, 3
• Allow adequate time for tissue infiltration and vasoconstriction before beginning procedure 3

Critical Safety Measures:

• Aspirate before injection to avoid intravascular administration 1
• Use incremental injections rather than bolus administration 1
• Continuously monitor patient for early signs of toxicity 1
• Ensure lipid emulsion is immediately available for treatment of local anesthetic systemic toxicity (LAST) 4

Pharmacokinetic Considerations

Absorption Profile:

• Peak serum lidocaine concentrations occur 12-16 hours after tumescent infiltration for liposuction (delayed due to epinephrine-induced vasoconstriction) 4
• Without epinephrine, peak concentrations occur much earlier at 1-2 hours 4
• The prolonged absorption time allows for higher total doses while maintaining serum levels below toxic threshold (5 μg/mL) 5, 4

Clinical Advantages

Benefits Over General Anesthesia:

• Eliminates risks associated with general anesthesia 3, 6
• Provides excellent bloodless surgical field due to epinephrine-induced vasoconstriction 3, 6
• Delivers prolonged postoperative analgesia (often 12-24 hours) 3
• Enables outpatient procedures with reduced costs 2, 3
• Reduces surgical complications including bleeding and hematoma formation 3

Important Safety Caveats

Monitoring Requirements:

• Patients require monitoring during procedure and for extended period afterward (minimum 12-16 hours for liposuction cases given delayed peak levels) 5, 4
• Staff must be trained to recognize early signs of LAST: circumoral numbness, metallic taste, tinnitus, confusion, seizures 1

Patient Selection Contraindications:

• Avoid in patients with significant cardiac or pulmonary disease 5
• Exercise caution with the 55 mg/kg dose—this is validated only for patients weighing 43.6-81.8 kg 1
• Risk of fluid overload exists despite subcutaneous administration; cases of pulmonary edema have been reported 5

Common Pitfall:

• Do not assume standard local anesthetic dosing limits apply to TLA—the pharmacokinetics are fundamentally different, but this does not eliminate toxicity risk 1, 4
• The maximum 55 mg/kg dose applies specifically to liposuction with appropriate technique; lower doses (28 mg/kg) should be used for other procedures 4