[Bupivacaine 0.5% and 0.75% for peridural anesthesia in operations on the extremities].

The safety of bupivacaine in respect of its cardiotoxicity has been discussed recently. Especially the concentration of bupivacaine 0.75% has been heavily criticized, first of all in obstetrical anaesthesia. Therefore two groups of patients receiving bupivacaine 0.5% and bupivacaine 0.75% were compared according to complications and side effects related to the local anaesthetic. 749 patients undergoing varicose vein stripping were divided in two groups: 371 patients received bupivacaine 0.5% with adrenalin 1:200,000 and 378 patients bupivacaine 0.75% with POR-8 (0.1 i.U./ml) for epidural anaesthesia. The average age was 46 years (20-71 y.). The average height 168 cm (149-196 cm), and the average weight 72 kg (40-99 kg). There were 68.7% female and 31.3% male patients in these groups. The anaesthesia charts of these patients were evaluated retrospectively. The incidence of hypotension, breadycardia, tachycardia, extrasystoles, vomiting and muscle twirching were taken as side effects. The two groups were compared. The results showed in relation to age, risk-grouping and the dosage/kg no evidence of an increased cardiotoxicity of the higher concentration of bupivacaine. Thus bupivacaine 0.75% does not show any increase in complications or side effects as long as its application is done correctly.