Articles: nerve-block.
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Acta Anaesthesiol Scand · Jan 2000
Randomized Controlled Trial Clinical TrialThe effects of clonidine on ropivacaine 0.75% in axillary perivascular brachial plexus block.
The new long-acting local anesthetic ropivacaine is a chemical congener of bupivacaine and mepivacaine. The admixture of clonidine to local anesthetics in peripheral nerve block has been reported to result in a prolonged block. The aim of the present study was to evaluate the effects of clonidine added to ropivacaine on onset, duration and quality of brachial plexus block. ⋯ The addition of clonidine to ropivacaine 0.75% does not lead to any advantage of block of the brachial plexus when compared with pure ropivacaine 0.75%.
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Anesthesia progress · Jan 2000
Inferior alveolar nerve block by injection into the pterygomandibular space anterior to the mandibular foramen: radiographic study of local anesthetic spread in the pterygomandibular space.
We studied the spread of local anesthetic solution in the inferior alveolar nerve block by the injection of local anesthetic solution into the pterygomandibular space anterior to the mandibular foramen (anterior technique). Seventeen volunteers were injected with 1.8 mL of a mixture containing lidocaine and contrast medium utilizing the anterior technique. ⋯ The results indicate that the contrast medium mixture spreads rapidly in the pterygomandibular space to the inferior alveolar nerve in the subjects who exhibited inferior alveolar nerve block effect. We concluded that the anesthetic effect due to the anterior technique was produced by the rapid distribution of anesthetic solution in the pterygomandibular space toward the mandibular foramen, and individual differences in the time of onset of analgesia may be due to differences in the histologic perineural tissues.
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Anesthesia and analgesia · Jan 2000
Clinical TrialMagnetic resonance imaging of the distribution of local anesthetic during the three-in-one block.
The three-in-one technique of simultaneously blocking the femoral, the lateral femoral cutaneous (LFC), and the obturator nerves by a single injection of a local anesthetic was first described in 1973, and it was suggested that the underlying mechanism was one of cephalad spread resulting in a blockade of the lumbar plexus. Today, the technique is widely used in surgery and pain management of the lower limb. Many investigators have, however, reported suboptimal analgesia levels, particularly in the obturator nerve. The purpose of this prospective study was to trace the distribution of a local anesthetic during a three-in-one block by means of magnetic resonance imaging (MRI). Seven patients scheduled for surgery of the lower limb were analyzed with the aid of a primary MRI and then received three-in-one blocks using 30 mL of bupivacaine 0.5% under the guidance of a nerve stimulator. A secondary MRI was performed to determine the distribution pattern of the local anesthetic. It emerged that the local anesthetic blocks the femoral nerve directly, the LFC nerve through lateral spread, and the anterior branch of the obturator nerve by slightly spreading in a medial direction. No involvement of the proximal and posterior portions of the obturator nerve was observed, nor was there any cephalad spread that could have resulted in a lumbar plexus blockade. We therefore conclude that the basis of the three-in-one block is confined to lateral, medial, and caudal spread of the local anesthetic, which effectively blocks the femoral and LFC nerves, as well as the distal anterior branch of the obturator nerve. ⋯ We demonstrate by using magnetic resonance imaging that the mechanism of a three-in-one block is one of lateral, caudal, and slight medial spread of a local anesthetic with subsequent blockade of the femoral, the lateral femoral cutaneous, and the anterior branch of the obturator nerves. It does not involve cephalad spread of the local anesthetic with blockade of the lumbar plexus.
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Foot and ankle operations are being performed with greater frequency as outpatient procedures. Although the surgical procedure remains the same whether the operation is done in an inpatient or an outpatient setting, the anesthesia and postoperative analgesia are greatly affected when patients must be discharged soon after their operation. ⋯ This was the sole anesthetic technique for both the operation and the immediate postoperative period. This technique appears to have several advantages: 1) Excellent anesthesia during the operation and for about ten hours postoperatively; 2) Use of a proximal calf tourniquet, and 3) Absence of systemic or local complications as might be seen with general, spinal or epidural anesthesia.