Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1996
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of the neuromuscular blocking effects of atracurium, mivacurium, and vecuronium on the adductor pollicis and the orbicularis oculi muscle in humans.
Both the orbicularis oculi (OO) and the adductor pollicis (AP) muscles have been used to indirectly quantify the extent of neuromuscular block of the respiratory muscles. To clarify any differences in response of these muscles to neuromuscular blocking drugs, the effects of two different doses of atracurium, mivacurium, and vecuronium on the AP and OO were studied. A new technique was used to measure the evoked mechanical response of the OO with accelerometry. ⋯ TOF 0.7 was shorter with the smaller dose of each drug, but there was no difference with the higher doses. It is concluded that it is possible to record the mechanical response of the OO muscle using a noninvasive method. There are differences between the responses of the OO and the AP to neuromuscular blockers that depend upon both the specific drug itself and the dose used.
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Anesthesia and analgesia · Oct 1996
Randomized Controlled Trial Clinical TrialAxillary brachial plexus anesthesia: electrical versus cold saline stimulation.
The aim of this study was to investigate which of two methods of nerve stimulation, cold saline-induced paresthesia or use of a nerve stimulator, was more effective in increasing the successful brachial plexus block rate by the axillary approach. Twenty patients were randomly assigned to Group A (saline below 11 degrees C), and 20 patients to Group B (nerve stimulator). All blocks were performed by the same anesthesiologist using 40 mL of 1.5% mepivacaine and 4 mL of 8.4% sodium bicarbonate. ⋯ A motor response was evoked by a nerve stimulator in 17 patients (85%). Two patients (10%) had a paresthesia in the hand without a motor response with the current at less than 1 mA. A successful block was achieved in 19 patients in each group.
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Anesthesia and analgesia · Oct 1996
The efficacy of axillary block for surgical procedures about the elbow.
Surgical procedures to the distal humerus, elbow, and proximal ulna and radius are ideally suited to regional techniques. However, axillary block is usually not recommended for surgery about the elbow because blockade at this level may result in inadequate block of the terminal nerves that arise from the medial, posterior, and lateral cords, and provide sensory innervation to the upper arm. This study reports the success rates for interscalene, supraclavicular, and axillary blocks for surgery about the elbow. ⋯ In addition, axillary blocks performed with mepivacaine had a higher success rate (93%) than those performed with bupivacaine (81%) (P < 0.01). There were no patients with perioperative respiratory compromise. These results demonstrate that the axillary approach to the brachial plexus may be successfully used for surgical procedures about the elbow.
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Anesthesia and analgesia · Oct 1996
Randomized Controlled Trial Clinical TrialSpinal bupivacaine in ambulatory surgery: the effect of saline dilution.
The safety of lidocaine spinal anesthesia has recently been called into question by reports of both permanent and transient neurologic toxicity. This study explored the possibility of adapting the longer acting spinal bupivacaine to ambulatory surgery. Sixty patients presenting for ambulatory arthroscopy were randomized to four groups receiving the following spinal anesthetics: Group I (15 mg bupivacaine), 3 mL of 0.5% spinal bupivacaine in 8% dextrose; Group II (10 mg bupivacaine), 2 mL of the 0.5% spinal bupivacaine+1 mL saline; Group III (7.5 mg bupivacaine), 1.5 mL of the 0.5% spinal bupivacaine%1.5 mL saline; Group IV (5 mg bupivacaine), 1 mL of the 0.5% spinal bupivacaine+2 mL saline. ⋯ The intensity of sensory block also decreased from group to group with four patients in Group IV having pain intraoperatively that required further treatment. Therefore, Group III provided the optimum combination of adequate depth of anesthesia and rapid recovery. The results of this study indicate that spinal anesthesia with 7.5 mg of 0.5% bupivacaine in 8% dextrose diluted with an equal volume of saline provides an acceptable spinal anesthetic for ambulatory arthroscopy with a recovery profile appropriate to the ambulatory setting.
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Anesthesia and analgesia · Oct 1996
Comparative StudyA comparison of the local anesthetic effects of meperidine, fentanyl, and sufentanil on dorsal root axons.
The local anesthetic effects of opioids have been demonstrated in both clinical and laboratory studies. Clinically, both meperidine and sufentanil can produce segmental sensory anesthesia. However, previous studies of the effects of opioids on nerve conduction have all made use of peripheral nerve preparations and yielded conflicting results. ⋯ Fentanyl (0.6 microM and 3 microM) and sufentanil (1.04 microM) failed to affect the nerve conduction in any dorsal root axon. The discrepancy between laboratory and clinical observations is discussed. We suggest that the site of conduction block may occur at the proximal end of the dorsal root as it passes through the dorsal root entry zone, an anatomically unique segment of the primary sensory pathway with decreased conduction safety for action potential propagation.