Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2008
Comparative StudyThe spinal antinociceptive effects of endomorphins in rats: behavioral and G protein functional studies.
Endomorphin-1 and endomorphin-2 are endogenous peptides that are highly selective for mu-opioid receptors. However, studies of their functional efficacy and selectivity are controversial. In this study, we systematically compared the effects of intrathecal (i.t.) administration of endomorphin-1 and -2 on nociception assays and G protein activation with those of [d-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (DAMGO), a highly effective peptidic mu-opioid receptor agonist. ⋯ Endomorphins are partial agonists for G protein activation at spinal and thalamic mu-opioid receptors. Both in vivo and in vitro measurements together suggest that DAMGO is more effective than endomorphins. Spinal endomorphins' antinociceptive efficacy may range between 53% and 84% depending on the intensity and modality of the nociceptive stimulus.
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Anesthesia and analgesia · Jun 2008
Does patient position influence Doppler signal quality from the USCOM ultrasonic cardiac output monitor?
The USCOM1A continuous wave cardiac output monitor (USCOM Pty Ltd., Sydney, NSW, Australia) is a novel Doppler-based device used to measure cardiac output noninvasively. The proper alignment of the transducer, and hence the ultrasound beam to the aortic or pulmonary outflow tracts, is essential to acquire accurate measurements and often much time is spent on transducer and/or patient positioning. In this prospective, observational, crossover study, we investigated the effect of patient positioning on the acquisition of cardiac output measurement with USCOM1A. ⋯ Our results suggested the sitting position is the least suitable and least reliable position in which to perform cardiac output measurements using USCOM1A compared with the supine, Trendelenburg (20 degrees), left lateral tilt (20 degrees), and right lateral tilt (20 degrees) positions.
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Anesthesia and analgesia · Jun 2008
Comparative Study Clinical TrialBispectral index values during sevoflurane-nitrous oxide general anesthesia in women undergoing cesarean delivery: a comparison between women with and without prior labor.
An end-tidal concentration of 1% sevoflurane (1% ET(SEVO)) in 50% nitrous oxide (N(2)O) during elective cesarean delivery has been associated with bispectral index (BIS) values >60, which are associated with an increased risk of awareness. We hypothesized that BIS values during sevoflurane-N(2)O general anesthesia for cesarean delivery would be lower in women with prior labor compared with women without prior labor. ⋯ Prior labor was associated with lower intraoperative BIS values during sevoflurane/N(2)O general anesthesia and reduced postoperative analgesic consumption in women undergoing cesarean delivery compared with women without prior labor.
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Anesthesia and analgesia · Jun 2008
Case ReportsAnesthetic management of a parturient with hyperhomocysteinemia.
High plasma levels of homocysteine are associated with an increased risk for thromboembolic events. Neuraxial anesthesia techniques may be relatively contraindicated in anticoagulated patients, and nitrous oxide may exacerbate the condition by inhibiting the conversion of homocysteine to methionine. We describe the anesthetic implications and management of a patient with hyperhomocysteinemia undergoing an nonemergent cesarean delivery.
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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.