Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Experimental pain models reveal no sex differences in pentazocine analgesia in humans.
Accumulating evidence suggests that there are sex differences in analgesic responses to opioid agonists. Several studies using an oral surgery pain model have reported more robust analgesia to kappa-agonist-antagonists (e.g., pentazocine, nalbuphine, butorphanol) among women than among men. However, evidence of sex differences in kappa-agonist-antagonist effects from studies of experimentally induced pain in humans is lacking. ⋯ These findings indicate significant analgesic responses to pentazocine in both men and women across multiple experimental pain assays, and the absence of sex differences contrasts with previous data from the oral surgery model. The most likely explanation for the discrepancy in results is that of differences in the pain assays. These findings are important because they suggest that sex differences in opioid analgesia may be specific to certain types of pain.
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Operating room fires fueled by surgical drapes and ignited by high-energy surgical tools in air and oxygen-enriched atmospheres continue to occur. ⋯ The results of this study reveal that with increasing oxygen concentration, the time to ignition becomes shorter, and the consequences become more severe. The possibility exists for manufacturers to develop drape materials that are safer than existing materials.
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For more than 30 yr, the in vitro contracture test (IVCT) was the only appropriate diagnostic tool for malignant hyperthermia (MH). After the introduction of molecular genetics into MH research, guidelines for molecular genetic diagnosis of MH susceptibility were published. The aim of this study was to establish applicability of the guidelines, sensitivity, and specificity of genetic testing in MH and advantages for studied patients. ⋯ In families with known MH mutations, there is a 50% chance of reliably confirming MH susceptibility by noninvasive testing. The authors found the negative predictive value of genetic testing to be 0.95 (95% confidence interval, 0.75-0.99), but for patient safety, they still recommend following the guidelines for genetic testing in MH and therefore performing an IVCT in case of negative genetic results.
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Comparative Study
Effects of dopamine, dobutamine, and dopexamine on microcirculatory blood flow in the gastrointestinal tract during sepsis and anesthesia.
Insufficient blood flow to the splanchnic organs is believed to be an important contributory factor for the development of organ failure after septic shock. It has been suggested that increasing systemic flow also may improve splanchnic blood flow in septic patients. The aim of this study was to compare the effects of three commonly used inotropic agents, dopamine, dobutamine, and dopexamine, on systemic (cardiac index), regional (superior mesenteric artery), and local (micro-circulatory) blood flow during septic shock in pigs. ⋯ All the inotropic agents markedly increased cardiac output in this sepsis model. However, increased systemic flow did not reach the microcirculation in the gastrointestinal tract. This may in part explain why some of the clinical trials, in which systemic oxygen delivery was deliberately increased by administration of inotropic drugs, have failed to improve survival in critically ill patients.
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Comparative Study
Effects of isoflurane versus fentanyl-nitrous oxide anesthesia on long-term outcome from severe forebrain ischemia in the rat.
This study examined long-term outcome from severe forebrain ischemia in the rat, as a function of anesthetic given during the ischemic injury. ⋯ This study found no change in the percent alive CA1 hippocampal neurons as a function of duration of recovery from severe forebrain ischemia in isoflurane anesthetized rats. In contrast, the percent alive CA1 neurons in fentanyl-nitrous oxide-anesthetized rats tripled over 3 months of recovery. The natural history of long-term responses to forebrain ischemia requires further study before conclusions can be drawn with respect to the permanence of isoflurane neuroprotection.