Combined ischiatic/3-in-1-block. II. 1 percent mepivacaine HCl versus 1 percent CO2 mepivacaine
Taeger, L.; Wagner, F.
Regional-Anaesthesie 11(2): 50-53
1988
ISSN/ISBN: 0171-1946 PMID: 2841724 Document Number: 317755
In a prospective randomized study on 26 patients, the clinical effectiveness CO2-mepivacaine 1% (group 1, 13 patients) and mepivacaine HCl 1% (group 2, 13 patients), was tested in patients having a sciatic-femoral block for surgical procedures of the lower extremity (20 ml for sciatic and 30 ml for 3-in-1 block). Blood levels of mepivacaine were determined for up to 90 min in 8 patients from each group. The onset of sensory and motor blockade was slightly earlier (4-5 min) with CO2-mepivacaine than with the hydrochloride (5-6 min). The time to complete block was 8-11 min with CO2-mepivacaine and 11-12 min with mepivacaine HCl. There was a relatively large variance in intensity of blockade that was not necessarily related to the drug employed, but can be explained by individual factors and possibly by slight differences in blocking technique. Nevertheless, the rate of unsuccessful blockade was remarkably higher (38%) with the hydrochloride than with CO2-mepivacaine (7.7%). Determinations of blood levels did show the expected earlier peak (after 20-30 min) and higher blood-levels (means 3.8 micrograms/ml at 30 min) with CO2-mepivacaine 1% as compared to mepivacaine HCl 1%: 2.9 micrograms/ml at 30 min and 3.4 micrograms/ml at 45 min.