Pharmakokinetische Untersuchungen bei der Tumeszenz-Lokalanästhesie mit Prilocain in der Varizenchirurgie

Off-label use of tumescent local anaesthesia in endovascular and surgical techniques

Tumescent local anaesthesia (TLA)has increasingly established itself as the anaesthesia method for operations on varicose veins and has become the standard method in the case of endovascular techniques. However, Off-label use occurs due to the reduced concentration of the local anaesthetic, the incorporation of additives together with a high quantity of LA which exceed the manufacturer’s recommended maximum dosage. In spite of a lack of significant complications arising from the approved use of the TLA and unambiguous positive evaluations of this anaesthesia method by international medical professional associations, the operating phlebologist should inform the patient of this Offlabel use both in the case of operative procedures and endovascular techniques in order to avoid any legal problems.

Pharmacokinetics of Articaine Hydrochloride in Tumescent Local Anesthesia for Liposuction

The aim of the investigation was to assess the pharmacokinetic characteristics and safety of articaine HCl used in tumescent local anesthesia for liposuction. Maximum plasma concentrations of articaine HCl were observed from 136 to 264 ng/mL, on average, from 1.2 to 4.3 hours after the start of infiltration, depending on the area of liposuction. The average extent of absorption ranged from 827 to 2203 ng*h/mL. Average maximum plasma concentrations of articainic acid ranged from 1719 to 7292 ng/mL. The high articainic acid concentrations at 1 hour after the start of infiltration indicate that articaine HCl was hydrolyzed rapidly by esterases in tissue and plasma. Although up to 38.2 mg/kg body weight articaine HCl was applied, no cardiac side effects or symptoms of central nervous intoxication occurred. Articaine HCl provided a safe and sufficient analgesia for tumescent liposuction.

Tumescent anaesthesia in combination with femoral nerve block for surgery of varicose veins: prilocaine 0.1% versus 0.2%

OBJECTIVE

Results of a prospective, randomized, double-blinded study about tumescent anaesthesia (TA) in combination with femoral nerve block (FNB) for surgery of varicose veins are reported. The aim is to compare two different concentrations of prilocaine in TA.

METHOD

With approval of the ethical committee and informed consent, FNB (nerve stimulation, 20 mL prilocaine 0.75%) was performed followed by TA using prilocaine 0.1% versus 0.2% (groups P0.1 and P0.2). Further medication was standardized. Overall amount of prilocaine was recorded, plasma levels of 20 patients measured regularly. Side-effects, patient satisfaction and pain scores were compared (P < 0.05).

RESULTS

Ninety patients were included. In one patient (P0.1), general anaesthesia was necessary. There was no difference in pain scores, need for rescue medication or patient satisfaction. More prilocaine was administered in P0.2 (P < 0.0001) with higher but far below toxic plasma levels. In three patients (P0.2) mild met-haemoglobinaemia was confirmed.

CONCLUSION

TA with prilocaine 0.1% in combination with FNB is sufficient to provide high patient satisfaction during varicosis surgery.