Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1996
Randomized Controlled Trial Comparative Study Clinical TrialThe effects of solution concentration and epinephrine on lateral distribution of hyperbaric tetracaine spinal anesthesia.
In a search of a differential spinal block between dependent and nondependent sides, we investigated whether the use of a larger concentration of hyperbaric tetracaine (T) and/or the omission of epinephrine (E) would provide differential spread in patients left for 15 min in the lateral decubitus position. Spinal anesthesia was performed in the lateral decubitus position with the operated side dependent in 60 patients scheduled for lower limb surgery. All patients remained lateral for 15 min after spinal injection before being turned supine. ⋯ A comparable number of patients in all groups showed unilateral motor block: four in T 0.5% + E, two in T 1% + E, four in T 0.5%, and five in T 1%. Likewise, a comparable number of patients in all groups showed a prolonged duration of sensory and motor block, respectively: six and eight in T 0.5% + E, six and nine in T 1% + E, six and eight in T 0.5%, and seven and seven in T 1%. In conclusion, although a preferential distribution of hyperbaric T toward the dependent side in patients of all four groups was noticed, the use of a larger concentration of T, omission of E, or combination of these two factors did not provide a more marked differential spread when compared to the standard solution of T 0.5% + E.
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Anesthesia and analgesia · Oct 1996
Randomized Controlled Trial Clinical TrialInteractions between mivacurium, rocuronium, and vecuronium during general anesthesia.
This study was designed to examine the interactions between mivacurium and rocuronium or vecuronium when administered during a standardized anesthetic technique. Seventy healthy women undergoing abdominal hysterectomy procedures with a standardized thiopental-sufentanil-desflurane-nitrous oxide anesthetic technique were randomly assigned to one of seven treatment groups (10 patients each). After a tracheal intubating dose of vecuronium 100 micrograms/kg (Groups 1 and 2), rocuronium 600 micrograms/kg (Groups 3 and 4), or mivacurium 250 micrograms/kg (Groups 5, 6, and 7), patients received vecuronium, 25 micrograms/kg (Groups 1 and 6), rocuronium 150 micrograms/kg (Groups 3 and 7), or mivacurium 50 micrograms/kg (Groups 2, 4, and 5) for maintenance of neuromuscular blockade. ⋯ The clinical duration of maintenance doses of vecuronium (18 +/- 6 min) and rocuronium (13 +/- 2 min) were significantly shorter after an intubating dose of mivacurium than that after an intubating dose of vecuronium (30 +/- 5 min) or rocuronium (42 +/- 12 min), respectively. These data suggest that with consecutive administration of neuromuscular blocking drugs, the initial duration of action depends more on the kinetics of the first neuromuscular blocking drug than the subsequent drug. Thus, there appears to be no clinical advantage in using mivacurium for maintenance of neuromuscular blockade after initial administration of rocuronium or vecuronium.
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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
ReviewPostoperative epidural opioid analgesia: what are the choices?
The administration of hydrophilic opioids via a continuous infusion results in selective spinal analgesia with a low incidence of side effects. Lipophilic opioids may also be associated with spinal effects. However, the doses required to produce postoperative analgesia also produce plasma concentrations within the MEAC. ⋯ Regardless of the mechanism of action, epidural administration of lipophilic opioids may offer no clinical advantages over the IV route. Notwithstanding, epidural administration of small doses of lipophilic opioids in combination with local anesthetics may offer significant clinical advantages over systemic administration of opioids alone. Dose-ranging studies will be necessary to determine the ideal concentrations of opioids and local anesthetics, as well as the ratios of the two drugs to obtain optimal analgesia with minimal incidence of side effects.
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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.