Anesthesia in outpatient phlebology practice

Tumescent and/or conductive anaesthesia is the most frequently performed procedure to anesthetize the thermal types of surgical interventions, mini-phlebectomy and stripping of subcutaneous veins in outpatient settings. These interventions have become a common outpatient procedure almost everywhere, which made the issue of local anaesthesia more sensitive over the past 5 years in Russia. The aim is to compare the efficacy, safety and comfort when injecting various anaesthetic solutions to relieve pain during endovenous laser obliteration/radio frequency catheter ablation, stripping of the subcutaneous veins and mini-phlebectomy. Searching method. We searched for original articles in PubMed, in the archives of «Phlebology» and «Angiology and Vascular Surgery» journals issued for the period between 2001 and November 2018 and the search for official instructions in the state register of medicinal products. Selection criteria. We included all comparative studies: randomized and non-randomized, in which pain was assessed both during injection of a tumescent solution before EVLO and/or mini-phlebectomy and during surgery, as well as systematic reviews and monographs. Data analysis. In total, we identified 9 studies: 7 randomized and 2 non-randomized, one systematic review and two monographs. The advantage of a buffered solution over unbuffered one in terms of reducing pain during injection is revealed in three randomized, one simple comparative study and on the basis of systematic review data. A great efficacy of combining tumescent anaesthesia with a femoral nerve blockade, which was equivalent to spinal anaesthesia, was found in 4 randomized trials, two of which were double-blind, and one non-randomized. In addition, a smaller degree of motor block was reported after blocking the femoral nerve in comparison with spinal anaesthesia. In one randomized trial in which pain was assessed using cold and warm solutions, no significant differences in pain were observed either during or after surgery. In order to prepare a tumescent solution, lidocaine, prilocaine and mepivacaine were used at concentrations ranging from 0.028% to 0.2%; the advantages of higher concentrations over the lower ones have not been revealed. No adverse reactions and complications of anaesthesia have been reported in the studies, except for one where methaemoglobinemia of mild degree was detected in a small number of patients when using 0.2% prilocaine. The conclusion. Local anaesthesia, namely, conductive and tumescent anaesthesia, is an effective and safe anaesthesia method in outpatient surgery. Even very low concentrations of anaesthetic solutions are effective for tumescent anaesthesia. The use of buffered solutions increases significantly patient comfort during the injection. The combination of tumescent anaesthesia and femoral nerve block increases the effectiveness of anaesthesia. The femoral nerve block has significant advantages in comparison with spinal anaesthesia in terms of safety.