What is the recommended protocol for tumescent (local infiltration) anesthesia?

Tumescent Anesthesia Protocol

For tumescent anesthesia in liposuction, use lidocaine with epinephrine at a maximum dose of 55 mg/kg in patients weighing 43.6-81.8 kg, administered as a warm (40°C) solution at a slow infiltration rate. 1

Anesthetic Agent Selection

Primary Recommendation: Lidocaine with Epinephrine

• Lidocaine with epinephrine is the recommended agent for tumescent anesthesia in liposuction 1
• The addition of epinephrine is both safe and recommended, providing vasoconstriction that reduces blood loss and slows systemic absorption 1
• This combination has Level I and II evidence supporting its use 1

Alternative: Prilocaine

• Prilocaine is safe and effective for tumescent anesthesia, though not FDA-approved for this indication in the United States 1
• A combination of lidocaine and prilocaine may reduce toxicity risk when large volumes are needed 1
• Critical caveat: Prilocaine carries risk of methemoglobinemia, particularly in susceptible patients (very young, G6PD deficiency, those on sulfonamides, acetaminophen, or other oxidizing drugs) 2

Agents NOT Recommended

• Bupivacaine has no data supporting its use in tumescent anesthesia and cannot be recommended 1

Dosing Guidelines

For Liposuction Procedures

• Maximum dose: 55 mg/kg of lidocaine with epinephrine 1
• This dosing is validated only for patients weighing 43.6-81.8 kg 1
• This represents significantly higher dosing than standard infiltrative anesthesia due to unique pharmacokinetics 3, 4

For Non-Liposuction Dermatologic Procedures

• Maximum dose should not exceed 28 mg/kg of lidocaine with epinephrine 4
• Standard infiltrative limits apply: 7.0 mg/kg lidocaine with epinephrine for adults 1
• For children: 3.0-4.5 mg/kg lidocaine with epinephrine 1

Important Pharmacokinetic Considerations

• Peak serum lidocaine levels occur 12-16 hours after tumescent infiltration for liposuction (when epinephrine is used) 4
• Without epinephrine, peak levels occur much earlier at 1-2 hours 4
• The slow absorption from subcutaneous tissue acts like a depot injection, allowing higher total doses 3
• Plasma concentrations remain below the toxic threshold of 5 mcg/mL when proper dosing is followed 5

Administration Technique

Solution Preparation

• Use dilute concentrations of local anesthetic 4
• Warm the solution to 40°C before administration 1
• Include epinephrine in the solution 1

Injection Protocol

• Administer at a slow infiltration rate 1
• Slower infusion decreases patient discomfort during administration 1
• Inject into subcutaneous tissue until it becomes firm and tense (tumescent) 6, 3
• Aspirate before each injection to avoid intravascular administration 1
• Use incremental injections 1

Pain Reduction Strategies

• Warming the solution to 40°C significantly reduces discomfort (Level II evidence) 1
• Slow infiltration rate reduces discomfort (Level III evidence) 1

Safety Monitoring

Prevention of Local Anesthetic Systemic Toxicity (LAST)

• Use the lowest effective dose 1
• Aspirate needle/catheter before each injection 1
• Use incremental injections 1
• Continuously monitor and communicate with the patient for early toxicity signs 1

Extended Monitoring Requirements

• Monitor patients for several hours after the procedure, as symptoms of LAST may not manifest until 12-16 hours post-injection 6, 4
• Have lipid emulsion therapy immediately available for treatment of LAST 6, 4
• Monitor for signs of fluid overload, as pulmonary edema has been reported 5

High-Risk Patients Requiring Extra Caution

• Patients with cardiac or pulmonary disease should not undergo tumescent anesthesia in outpatient settings 5
• Debilitated or elderly patients require dose reduction 2
• Patients on medications affecting hepatic drug clearance need dosage adjustments 3
• Those with conditions reducing liver blood supply require lower doses 3

Common Pitfalls to Avoid

Dosing Errors

• Do not extrapolate the 55 mg/kg liposuction dose to patients outside the 43.6-81.8 kg weight range 1
• Do not use liposuction dosing (55 mg/kg) for non-liposuction procedures—use 28 mg/kg maximum instead 4
• Do not assume standard infiltrative anesthesia dosing limits (7 mg/kg) apply to tumescent technique for liposuction 1

Monitoring Failures

• Do not discharge patients immediately after the procedure—peak levels occur many hours later 6, 4
• Do not assume absence of early symptoms means safety—toxicity can be delayed 6

Epinephrine-Related Issues

• Be aware of potential tachycardia, arrhythmias, and hypertension from high-dose epinephrine 5
• Use caution in patients with hypertensive or peripheral vascular disease 2