Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2003
Antinociception with intrathecal alpha-methyl-5-hydroxytryptamine, a 5-hydroxytryptamine 2A/2C receptor agonist, in two rat models of sustained pain.
Type 2 serotonin (5-hydroxytryptamine [5-HT](2)) receptors in the spinal cord have been reported to mediate antinociception using pain threshold tests, but little is known about the actions of spinal 5-HT(2) receptors in sustained pain. In rats, we examined antinociceptive effects of the intrathecal administration of a 5-HT(2A/2C) receptor agonist, alpha-methyl-5-HT maleate (alpha-m-5-HT), using the formalin test and the chronic constriction injury (CCI) model. An intrathecal catheter was implanted for injection of drugs. In the formalin test, flinches were counted from Minute 1 to 2 and Minute 5 to 6 (Phase 1) and then for 1-min periods at 5-min intervals from 10 to 60 min (Phase 2). In rats with CCI, hind paw withdrawal latency after thermal stimulation was measured. In the formalin test, intrathecal administration of alpha-m-5-HT (1 to 100 microg) dose-dependently suppressed the number of flinches in both Phases 1 and 2. In the CCI model, intrathecally administered alpha-m-5-HT (10 to 100 microg) attenuated thermal hyperalgesia in a dose-dependent manner. These effects were reversed by intrathecal pretreatment with a 5-HT(2A/2C) antagonist, ketanserin (30 microg), or a muscarinic receptor antagonist, atropine (30 microg). These findings suggest that spinal 5-HT(2A/2C) receptors mediate antinociception in inflammatory pain and neuropathic pain, and the muscarinic receptors contribute to this action. ⋯ Activation of spinal 5-hydroxytryptamine(2A/2C) receptors mediate antinociception in rat-sustained pain models such as inflammatory pain and neuropathic pain, and spinal muscarinic receptors are involved in this action.
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Anesthesia and analgesia · Apr 2003
The influence of induced hypothermia for hemostatic function on temperature-adjusted measurements in rabbits.
In hypothermic patients, a tendency to bleed may be observed even when hemostatic tests seem to be normal. Coagulation and platelet function tests are usually performed at 37 degrees C. We investigated the influence of induced hypothermia on temperature-adjusted hemostasis function testing using Sonoclot Analyzer (Sonoclot) and Thromboelastography (TEG). Anesthesia was induced and maintained with IV ketamine and fentanyl on 15 male New-Zealand White rabbits. A water blanket was used to induce hypothermia to 30 degrees C and to rewarm to 37 degrees C. Blood samples were obtained at four points: before hypothermia, at 34 degrees C, at 30 degrees C, and after rewarming. Standard coagulation tests were performed at 37 degrees C (C method), and simultaneously, real temperature hemostasis function tests (R method) were run. In Sonoclot(R), activated clotting time and time to peak increased and clot rate decreased significantly at 30 degrees C in the R method compared with those in the C method. In TEG(R), reaction time and clot formation time were prolonged and clot formation rate was diminished at 30 degrees C in the R method compared with those in the C method. Induced hypothermia delayed the coagulation cascade and reduced platelet function. During hypothermia, hemostatic measurements should be performed at real temperature to avoid overestimating patient hemostatic function based on results measured at the standard 37 degrees C. ⋯ We investigated the influence of induced hypothermia on temperature-adjusted hemostasis function tests in rabbits using Sonoclot Analyzer and Thromboelastography. Induced hypothermia delayed the coagulation cascade and reduced platelet function. The conventional coagulation tests performed at 37 degrees C failed to detect these hypothermia-induced degradations in hemostasis performance.
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Anesthesia and analgesia · Apr 2003
Case ReportsSeizure after levobupivacaine for interscalene brachial plexus block.
This case report describes a patient who demonstrated generalized seizure activity after an injection of 30 mL of levobupivacaine 0.5% for interscalene brachial plexus block. No evidence of cardiovascular toxicity was noted.
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Anesthesia and analgesia · Apr 2003
Labor costs incurred by anesthesiology groups because of operating rooms not being allocated and cases not being scheduled to maximize operating room efficiency.
Determination of operating room (OR) block allocation and case scheduling is often not based on maximizing OR efficiency, but rather on tradition and surgeon convenience. As a result, anesthesiology groups often incur additional labor costs. When negotiating financial support, heads of anesthesiology departments are often challenged to justify the subsidy necessary to offset these additional labor costs. In this study, we describe a method for calculating a statistically sound estimate of the excess labor costs incurred by an anesthesiology group because of inefficient OR allocation and case scheduling. OR information system and anesthesia staffing data for 1 yr were obtained from two university hospitals. Optimal OR allocation for each surgical service was determined by maximizing the efficiency of use of the OR staff. Hourly costs were converted to dollar amounts by using the nationwide median compensation for academic and private-practice anesthesia providers. Differences between actual costs and the optimal OR allocation were determined. For Hospital A, estimated annual excess labor costs were $1.6 million (95% confidence interval, $1.5-$1.7 million) and $2.0 million ($1.89-$2.05 million) when academic and private-practice compensation, respectively, was calculated. For Hospital B, excess labor costs were $1.0 million ($1.08-$1.17 million) and $1.4 million ($1.32-1.43 million) for academic and private-practice compensation, respectively. This study demonstrates a methodology for an anesthesiology group to estimate its excess labor costs. The group can then use these estimates when negotiating for subsidies with its hospital, medical school, or multispecialty medical group. ⋯ We describe a new application for a previously reported statistical method to calculate operating room (OR) allocations to maximize OR efficiency. When optimal OR allocations and case scheduling are not implemented, the resulting increase in labor costs can be used in negotiations as a statistically sound estimate for the increased labor cost to the anesthesiology department.
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Anesthesia and analgesia · Apr 2003
Case ReportsProlonged dexmedetomidine infusion as an adjunct in treating sedation-induced withdrawal.
Dexmedetomidine, an alpha(2)-adrenoceptor agonist, is indicated for sedating patients on mechanical ventilation. It has been approved by the Food and Drug Administration for 24-h use. This is a report concerning a patient in whom a continuous infusion of dexmedetomidine was safely used for a week to help in averting frank withdrawal symptoms from an opioid and benzodiazepines.