Anesthesiology
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Although experimental evidence indicates that preemptive intrathecal treatment with local anesthetics reduces postinjury neuronal hyperexcitability, clinical evidence indicates that preemptive treatments do not consistently reduce postoperative pain. The current study used experimental models of postinjury nociception, in which rats received subcutaneous or intraarticular injections of the irritant formalin, to evaluate the effects of peripheral inflammation, or the use of agents supplemental to anesthesia, as possible confounding influences on the effectiveness of preinjury and postinjury intrathecal local anesthetic treatments. ⋯ The current results attest to the important effects of ongoing inputs from inflamed tissue, and the use of supplemental treatments, as important confounding factors that may influence the effectiveness of preemptive spinal anesthesia for postoperative pain.
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Recent evidence has suggested that the timing of administration of analgesic drugs could influence their efficacy by reducing the sensitization of the nervous system induced by the nociceptive inputs, but this concept of preemptive analgesia is still debated in both clinical and basic research. ⋯ These results show that a slight advantage of infiltration with bupivacaine before injury exists in this carrageenin model of acute inflammatory pain. However, this benefit is limited in time and bupivacaine did not have any preemptive analgesic effect.
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Randomized Controlled Trial Clinical Trial
Repeated doses of rocuronium bromide administered to cirrhotic and control patients receiving isoflurane. A clinical and pharmacokinetic study.
Steroid muscle relaxants often display pharmacodynamic changes in patients with cirrhosis because of alterations in elimination processes. Rocuronium is a new steroid muscle relaxant possibly eliminated through the liver. This study was designed to compare rocuronium pharmacodynamics and pharmacokinetics in cirrhotic and healthy patients. ⋯ Rocuronium pharmacodynamics are moderately altered by cirrhosis, possible because of pharmacokinetic alterations. Individual variability in response to rocuronium is great, and dosage should be carefully titrated to that required.
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Randomized Controlled Trial Clinical Trial
Fiberoptic intubation using anesthetized, paralyzed, apneic patients. Results of a resident training program.
There is no consensus about the best way to teach fiberoptic intubation. This study assesses the effectiveness of a training program in which novice anesthetic residents routinely were taught fiberoptic tracheal intubation of anesthetized, paralyzed, apneic patients. ⋯ Novices taught fiberoptic intubation and rigid laryngoscopic intubation under similar conditions, with similar volumes of experience, learn both techniques well. The safety and effectiveness of this training regimen commend it for inclusion in any residency program.
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Randomized Controlled Trial Clinical Trial
Desflurane-mediated neurocirculatory activation in humans. Effects of concentration and rate of change on responses.
Rapid increases in the inspired concentration of desflurane have been associated with sympathetic activation, tachycardia, hypertension, and in select cases, myocardial ischemia. The current study examined the effects of the rate of change of the desflurane concentration on the sympathetic and hemodynamic responses to desflurane and sought to determine whether a finite concentration (end-tidal) of desflurane consistently initiated these responses. ⋯ There was no consistent threshold for the neurocirculatory activation associated with desflurane, and the HR and SNA thresholds generally were less than 1 MAC. The HR increase associated with desflurane was not rate- or concentration-dependent. In contrast, SNA responses were proportional to the rate of change and the concentration of desflurane.