Articles: nerve-block.
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Anesthesia and analgesia · Oct 2005
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialUsing stimulating catheters for continuous sciatic nerve block shortens onset time of surgical block and minimizes postoperative consumption of pain medication after halux valgus repair as compared with conventional nonstimulating catheters.
We prospectively tested the hypothesis that the use of a stimulating catheter improves the efficacy of continuous posterior popliteal sciatic nerve block in 100 randomized patients scheduled for elective orthopedic foot surgery. After eliciting a sciatic mediated muscular twitch at < or = 0.5 mA nerve stimulation output, the perineural catheter was advanced 2-4 cm beyond the tip of the introducer either blindly (Group C; n = 50) or stimulating via the catheter (Group S; n = 50). A bolus dose of 25 mL of 1.5% mepivacaine was followed by a postoperative patient-controlled infusion of 0.2% ropivacaine (basal infusion: 3 mL/h; incremental dose: 5 mL; lockout time: 30 min). Propacetamol 2 g IV was administered every 8 h, and opioid rescue analgesia was available if required. Catheter placement required 7 +/- 2 min in Group S and 5 +/- 2 min in Group C (P = 0.056). A significantly shorter onset time of both sensory and motor blocks was noted in Group S. No difference in quality of pain relief at rest and during motion was reported between the groups. Median (range) local anesthetic consumption during the first 48 h after surgery was 239 mL (175-519 mL) and 322 mL (184-508 mL) in Groups S and C, respectively (P = 0.002). Rescue opioid analgesia was required by 12 (25%) and 28 (58%) patients in Groups S and C, respectively (P = 0.002). We conclude that the use of a stimulating catheter results in shorter onset time of posterior popliteal sciatic nerve block, similar pain relief with reduced postoperative consumption of local anesthetic solution, and less rescue opioid consumption. ⋯ This prospective, randomized, blind investigation demonstrated that the use of a stimulating catheter for continuous posterior popliteal sciatic nerve block resulted in shorter onset time of sensory and motor blocks and less local anesthetic consumption and need for rescue pain medication after elective orthopedic foot surgery compared with blind catheter advancement.
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Reg Anesth Pain Med · Sep 2005
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialA prospective crossover comparison study of the single-needle and multiple-needle techniques for facet-joint medial branch block.
Medial branch blocks have been widely described in the literature as a diagnostic tool for facet joint pain. Recently, a new "single-needle' technique was described that is purported to be equally accurate, and in some respects, superior to the standard multiple-needle technique. To date, no studies have been performed that compared these 2 techniques. ⋯ Our results indicate that the single-needle technique takes less time to perform and causes less patient discomfort than does the standard technique but provides the same degree of accuracy. More studies with larger sample sizes are needed to corroborate these results and explore the effect the single-needle approach has on the rate of false-positive medial branch blocks.
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Reg Anesth Pain Med · Jul 2005
Multicenter StudyClinical evaluation of the lateral sagittal infraclavicular block developed by MRI studies.
Lateral sagittal infraclavicular block by single injection has a faster performance time and causes less discomfort than does axillary block by multiple injections. This prospective, descriptive, multicenter study assessed block effectiveness, onset time, and incidence of adverse events and verified the noninvasive measurements from magnetic resonance imaging (MRI). ⋯ Block effectiveness (91%) and onset time (20 minutes) were satisfactory and comparable to the vertical paracoracoid approach. The low rate of axillary vessel punctures (2%) may be the most important advantage of this block. The needle insertion depth measurements confirmed the MRI findings, but the dorsal angle was steeper than predicted.
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Paediatric anaesthesia · Sep 2004
Multicenter Study Clinical TrialRopivacaine in neonates and infants: a population pharmacokinetic evaluation following single caudal block.
The aims of this study were to evaluate pharmacokinetics, efficacy and safety of ropivacaine in infants aged 0-12 months following a single caudal injection. ⋯ Following a caudal block with ropivacaine 2 mg x kg(-1) plasma concentrations of unbound ropivacaine were well below threshold levels for toxicity in adults. Apparent volume of distribution is unchanged, apparent unbound clearance increases and the terminal half-life decreases with age in 0-12-month-old neonates and infants. The postoperative pain management provided adequate analgesia and was well tolerated.
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Anesthesia and analgesia · Jun 2004
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialPosttetanic potentiation and fade in the response to tetanic and train-of-four stimulation during succinylcholine-induced block.
We designed this study to confirm anecdotal observations that neuromuscular block after a single administration of succinylcholine is characterized by fade to train-of-four (TOF) or tetanic stimulation, as well as posttetanic potentiation. This prospective, randomized, 2-center observational study involved 100 patients. Patients were allocated to 1 of 5 groups and received 0.1, 0.3, 0.5, 0.75, or 1.0 mg/kg succinylcholine during propofol/fentanyl/nitrous oxide anesthesia. Neuromuscular function was monitored by TOF using mechanomyography. At 10%-20% spontaneous recovery of the first twitch of TOF, the mode of stimulation was changed from TOF to 1-Hz single-twitch stimulation followed by a tetanic stimulus (50 Hz) for 5 s. Three seconds later, the single twitch (1 Hz) was applied again for approximately 30 s followed by TOF stimulation until full recovery of the TOF response. Succinylcholine-induced neuromuscular block had the following characteristics: 1) twitch augmentation before twitch depression, which was seen more frequently in patients given smaller doses (0.1 and 0.3 mg/kg) than in those given larger doses (0.5-1.0 mg/kg); 2) TOF fade during onset and recovery of the block; 3) tetanic fade; and 4) and posttetanic potentiation. Posttetanic potentiation was related to the pretetanic twitch height but was not related to the dose of succinylcholine administered. Some characteristics of Phase II block were detectable during onset and recovery from doses of succinylcholine as small as 0.30 mg/kg. Posttetanic potentiation and fade in response to train-of-four and tetanic stimuli are characteristics of neuromuscular block after bolus administration of different doses of succinylcholine. ⋯ Posttetanic potentiation and fade in response to train-of-four and tetanic stimuli are characteristics of neuromuscular block after bolus administration of different doses of succinylcholine. We also conclude that some characteristics of a Phase II block are evident from an initial dose (i.e., as small as 0.3 mg/kg) of succinylcholine.