Articles: nerve-block.
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Regional-Anaesthesie · Jan 1988
Comparative Study[Comparison of bupivacaine hydrochloride 0.5% and bupivacaine carbonate 0.5% in interscalene plexus anesthesia].
Carbonated local anesthetics are less acidic than the hydrochlorides and require less buffering by the tissues. Rapid buffering and diffusion of the carbon dioxide enables free base to be deposited in high concentrations on nerve fibres. Carbon dioxide increases the intracellular hydrogen ion concentration, thus increasing the amount of active cation at the receptor site. ⋯ The first analgesia was detected by pinprick 5.1 +/- 0.4 (SE) min and complete analgesia in 19 +/- 1 min after bupivacaine hydrochloride and 4.7 +/- 0.5 min and 15 +/- 1 min after bupivacaine carbonate. The more caudad nerves showed a significantly longer latency time than the more cephalad ones. The duration of sensory analgesia varied between 6 and 12 hours, the more caudad nerves showing the shortest duration.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Dec 1987
Comparative Study Clinical Trial Controlled Clinical TrialClinical pharmacokinetics of carbonated local anesthetics. II: Interscalene brachial block model.
A double-blind comparison of 1.1% lidocaine carbonate and 1.0% lidocaine hydrochloride was carried out in 30 healthy adult patients undergoing upper-extremity surgery under interscalene brachial plexus block. Epinephrine (1:200,000) was added to both solutions just before injection. As compared to lidocaine hydrochloride, lidocaine carbonate produced, in addition to a 38% reduction in onset time, a remarkable increase in the extent of anesthesia: lidocaine carbonate produced surgical anesthesia of the entire upper extremity including the hand in 87% of the patients, whereas lidocaine hydrochloride produced similar anesthesia in only 53% of the patients. Thus, supplemental blocks were required in 66% of the patients who received lidocaine hydrochloride, whereas they were required in only 25% of those who received lidocaine carbonate.