Articles: nerve-block.
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Anesthesia and analgesia · Jul 2002
Randomized Controlled Trial Comparative Study Clinical TrialThe relative motor blocking potencies of epidural bupivacaine and ropivacaine in labor.
Minimal local analgesic concentrations (MLAC) have been used to determine the epidural analgesic potencies of bupivacaine and ropivacaine. There are no reports of the motor blocking potencies of these drugs. We sought to determine the motor block MLAC of both drugs and their relative potency ratio. Sixty ASA physical status I and II parturients were randomized to one of two groups, during the first stage of labor. Each received a 20-mL bolus of epidural bupivacaine or ropivacaine. The first woman in each group received 0.35%. Up-down sequential allocation was used to determine subsequent concentrations at a testing interval of 0.025%. Effective motor block was defined as a Bromage score <4 within 30 min. The up-down sequences were analyzed by using the Dixon and Massey method and probit regression to quantify the motor block minimal local analgesic concentration. Two-sided P < 0.05 defined significance. The motor block minimal local analgesic concentration for bupivacaine was 0.326% (95% confidence interval [CI], 0.285-0.367) and for ropivacaine was 0.497% (95% CI, 0.431-0.563) (P = 0.0008). The ropivacaine/bupivacaine potency ratio was 0.66 (95% CI, 0.52-0.82). This is the first MLAC study to estimate the motor blocking potencies of bupivacaine and ropivacaine. Ropivacaine was significantly less potent for motor block, at 66% that of bupivacaine. ⋯ The results of this study demonstrate that epidural ropivacaine is less potent than epidural bupivacaine in producing motor blockade during labor. The motor block potency relation is similar to the sensory potency ratio for these two drugs.
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Minerva anestesiologica · Jul 2002
0.25% levo-bupivacaine for interscalene block during shoulder surgery. A survey on 20 patients.
Interscalene brachial plexus block (ISB) is an alternative procedure to general anaesthesia for shoulder surgery, and consents the anaesthetist to easily control postoperative pain that, indeed, is known to be intense and often requires strong analgesic administration. The introduction of regional anaesthesia for this type of surgery, contributed to the relief of acute postoperative pain occurring in the recovery room since the analgesic effects of block persist for several hours after surgery depending upon the selected drug. The aim of this study was to determine the effects of 40 ml of 0.25% levo-bupivacaine, a local anaesthetic derived from the racemic mixture of bupivacaine, on the speed of onset, quality and duration of ISB. ⋯ Levobupivacaine is a newly developed local anaesthetic derived from a bupivacaine racemic mixture from which the right isomer has been eliminated. Levo-bupivacaine, compared to racemic mixture, is acknowledged to be less cardiotoxic, faster at equal dosage, and ensures a longer analgesic interval. Zero point twenty-five percent concentration was preferred in this study in order to inject large volumes (40 ml) with a minimal anaesthetic amount (100 mg), resulting in short time for obtaining loss of sensibility, optimal intraoperative conditions and long lasting block with adequate postoperative analgesia.
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This study was performed to evaluate the feasibility of using a joystick-controlled robotic needle driver to place a 22-gauge needle for nerve and facet blocks. ⋯ A robotic needle driver can be used to place needles accurately in the nerve and facet regions. Clinical studies are required to investigate the advantages and disadvantages of this system for interventional procedures involving needles.