Tumescent anaesthesia: its applications and well tolerated use in the out-of-operating room setting

Tumescent anaesthesia is a method of administering dilute local anaesthetic into the subcutaneous tissue. Many anaesthesiologists are unfamiliar with the technique, its applications and potential risks.

The maximum safe dose of lidocaine with epinephrine in tumescent anaesthesia for liposuction is probably between 35 and 55 mg/kg. Without liposuction, the maximum dose of lidocaine with epinephrine should be no more than 28 mg/kg. After tumescent infiltration for liposuction, serum lidocaine concentrations peak between 12 and 16 h after injection. When tumescent lidocaine without epinephrine is used for endovenous laser therapy, peak serum lidocaine concentrations are observed much earlier, between 1 and 2 h after injection. Slow administration of more dilute concentrations of local anaesthetic decreases the risk of local anaesthetic systemic toxicity.

Although appealing because of its ability to provide prolonged analgesia, high doses of local anaesthetic are frequently administered using the tumescent technique, and absorption of local anaesthetic from the subcutaneous tissue is variable. When caring for patients having procedures in which tumescent anaesthesia is used, the risk of local anaesthetic toxicity should be acknowledged and lipid emulsion should be available for prompt treatment if needed.