Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2008
Hypothermia and acidosis synergistically impair coagulation in human whole blood.
Hypothermia and acidosis were reported to influence coagulopathy in different clinical settings. We evaluated whole blood coagulation to determine the effects of hypothermia and/or acidosis on hemostasis. ⋯ In this in vitro study, hypothermia produced coagulation changes that were worsened by acidosis whereas acidosis without hypothermia has no significant effect on coagulation, as studied by thromboelastometry. This effect was mediated by the inhibition of coagulation factors and platelet function. Thus, thromboelastometry performed at 37 degrees C overestimated integrity of coagulation during hypothermia in particular in combination with acidosis.
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Anesthesia and analgesia · Jun 2008
Comparative StudyThe effect of prolonged anesthesia with isoflurane, propofol, dexmedetomidine, or ketamine on neural cell proliferation in the adult rat.
Recent evidence indicates that new neurons are produced in the adult hippocampus, and play a functional role in cognitive processes such as learning and memory. In animals, new neuron production is suppressed by increasing age, gamma-aminobutyric acid receptor activity, reductions in basal forebrain activity and brain norepinephrine levels, and decreased environmental stimuli. Similarities between these effects and those of anesthetic administration suggest that anesthetics may modulate new cell production, and raise the possibility that postoperative cognitive dysfunction may result, in part, from anesthetic-induced suppression of adult neurogenesis. To test this hypothesis, we investigated the effects of prolonged anesthesia with four different anesthetics on hippocampal cell proliferation in young and older rats. ⋯ Despite using multiple, mechanistically distinct drugs, we found no effect of prolonged anesthesia on adult hippocampal cell proliferation in young rats, a slight suppressive effect of ketamine in older rats, and no circadian effect with isoflurane. These data indicate that anesthetics are unlikely to alter cell proliferation, and by extension that anesthetic-induced inhibition of cell proliferation is unlikely to play a major role in postoperative cognitive impairment. The contrast between our findings, current concepts of anesthetic action, and known modifiers of cell proliferation suggest an incomplete understanding of the pharmacological and behavioral factors governing new neuron production.
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Anesthesia and analgesia · Jun 2008
The effects of aromatic anesthetics on dorsal horn neuronal responses to noxious stimulation.
Gamma-aminobutyric acid type A receptor potentiation and/or N-methyl-d-aspartate (NMDA) receptor inhibition might explain the anesthetic properties of fluorinated aromatic compounds. We hypothesized that depression of dorsal horn neuronal responses to noxious stimulation would correlate with the magnitude of effect of benzene (BNZ), o-difluorobenzene, and hexafluorobenzene (HFB) on NMDA receptors. ⋯ The findings in intact rats suggest that NMDA blockade contributes to the depression of dorsal horn neurons to nociceptive stimulation by fluorinated aromatic anesthetics. These results, combined with the additional findings in decerebrate rats, suggest that supraspinal effects (perhaps on gamma-aminobutyric acid type A receptors) may have a supraspinal facilitatory effect on nociception for HFB.
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Anesthesia and analgesia · Jun 2008
Comparative StudyThe antinociceptive effects of anticonvulsants in a mouse visceral pain model.
There is evidence supporting the antinociceptive effects of carbamazepine, oxcarbazepine, gabapentin, and topiramate in various models of neuropathic pain as well as inflammatory somatic pain. Data are lacking on the antinociceptive potential of these drugs against visceral pain. In this study, we examined and compared the effects of carbamazepine, oxcarbazepine, gabapentin, and topiramate in the writhing test as a visceral pain model in the mouse. In addition, the influence of these anticonvulsants on motor performance was examined to compare the tolerability of these anticonvulsants when used against acute visceral pain. ⋯ These results indicate that oxcarbazepine, gabapentin, and topiramate are effective in the writhing model in mice, in a dose range, which is not related to motor impairment; topiramate is the most potent and the most tolerable drug.
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Anesthesia and analgesia · Jun 2008
Teaching and evaluating group competency in systems-based practice in anesthesiology.
Teaching and assessment of the systems-based practice competency has been problematic in hospital-based specialties such as anesthesiology. We developed a method to teach systems-based practice with collaborative team projects. The outcome was assessed with a tool that focused on group attributes. ⋯ We developed an innovative method to teach systems-based practice through a team-based project initiative. The projects appear to have had a positive impact on our health care organization. Our assessment tool for the project evaluated team, rather than individual, performance, which is crucial in this competency.