Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Jan 1999
Randomized Controlled Trial Comparative Study Clinical TrialEfficacy of ondansetron in prophylaxis of postoperative nausea and vomiting in patients following infratentorial surgery: a placebo-controlled prospective double-blind study.
In a prospective double blind placebo-controlled study, 45 patients scheduled for infratentorial surgery were randomly allocated into two groups. Five patients were later excluded from the study because of various reasons. Out of 40 analyzable patients, 20 received IV Ondansetron (4 mg), whereas the other 20 received the matching placebo approximately 1 hour before the skin closure. ⋯ A significantly higher number of patients remained sedated postoperatively in the Ondansetron group than in the placebo group (p<0.05). One patient in the Ondansetron group had protracted diarrhea for 48 hours postoperatively. These results indicate that administration of IV Ondansetron (4 mg) 1 hour before skin closure effectively reduces PONV after infratentorial surgery, and does not have significant adverse effects.
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J Neurosurg Anesthesiol · Jan 1999
Comparative StudyAn assessment of contributions made by extracranial tissues during cerebral oximetry.
This study was designed to determine the extent of contribution made by extracranial tissues to estimation of regional cerebrovascular saturation (ScO2) during cerebral oximetry. Thirty four patients undergoing carotid endarterectomy under regional anesthesia were studied. Bilateral ScO2 monitoring with two INVOS 3100 A cerebral oximeters was used. ⋯ After release of all clamps ipsilateral ScO2 returned toward baseline but remained significantly lower (p<0.05) than pre clamp values. When readings from two hemispheres were compared, a significant difference (p<0.001) was noted during ICA occlusion only. We conclude that the mathematical algorithm used for calculation of ScO2 by INVOS 3100 A cerebral oximeter measures predominantly the intracranial cerebrovascular saturation.
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J Neurosurg Anesthesiol · Jan 1999
Comparative StudyInhibition of nitric oxide metabolism enhances the hypnotic-anesthetic action of the alpha2-adrenoceptor agonist dexmedetomidine in vivo.
Nitric oxide (NO) synthase inhibitors have been demonstrated to increase the anesthetic action of volatile and intravenous anesthetics. This study was designed to test the hypothesis that, comparable to other general anesthetics, the hypnotic-anesthetic action of dexmedetomidine is increased after administration of the NO synthase inhibitor nitro-L-arginine methyl ester (L-NAME). With approval of the local animal care committee, the anesthetic potency of dexmedetomidine or a combination of dexmedetomidine plus 1 mM L-NAME was determined in Xenopus laevis larvae. ⋯ Administration of D-NAME did not affect the EC50 of dexmedetomidine. In a manner comparable to that of other general anesthetics, the anesthetic effect of dexmedetomidine was increased by about 51% by an acute inhibition of the NO metabolism. Together with recent findings that alpha2-adrenoceptor agonists decrease the NO mediated synthesis of cGMP similar to volatile and intravenous anesthetics, the results suggest that the NO/cGMP pathway is an important mediator of the anesthetic action of these compounds.
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J Neurosurg Anesthesiol · Jan 1999
Effect of inhalational anesthesia on cerebral circulation in Moyamoya disease.
To clarify the effects of inhalational anesthesia on cerebral circulation in patients with Moyamoya disease, the authors measured regional cortical blood flow (CoBF), jugular bulb oxygen saturation (SjO2), and frontal regional oxygen saturation (rSO2) by near infra-red spectroscopy under total intravenous and inhalational anesthesia in 13 patients undergoing revascularization procedures. Cortical blood flow decreased in some regions under inhaled anesthesia in all cases, and the mean value decreased significantly (p<0.01). ⋯ Regional CoBF levels may be decreased by inhaled anesthesia in patients with Moyamoya disease, and such anesthesia may provoke intracerebral steal. Total intravenous anesthesia, however, lacked these effects.
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J Neurosurg Anesthesiol · Jan 1999
Comparative StudyEffects of postischemic halothane administration on outcome from transient focal cerebral ischemia in the rat.
This study examined the effect of prolonged postischemic halothane administration on outcome from transient focal cerebral ischemia in rats. Conscious normothermic rats were subjected to 75 minutes of filament middle cerebral artery occlusion (MCAO). Animals were then divided into two groups. ⋯ Cortical (Awake = 76+/-57 mm3; Halothane = 90+/-57 mm3; p = 0.494, mean +/- standard deviation), subcortical (Awake = 71+/-33 mm3; Halothane = 80+/-35 mm3; p = 0.472), and total (Awake = 147+/-88 mm3; Halothane = 171+/-91 mm3; p = 0.477) infarct volumes were not significantly different between groups. The data indicate that postischemic halothane administration offers no benefit in ameliorating damage from focal cerebral ischemia. This suggests that the neuroprotective effect of halothane observed in other studies is consistent with influences on intra-ischemic pathophysiology only.