Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Apr 1995
Nitrous oxide added to isoflurane increases brain artery blood flow and low frequency brain electrical activity.
Although changes in cerebral blood flow (CBF) and the electroencephalogram (EEG) have been reported with nitrous oxide (N2O) administration, the interaction of these parameters is unclear. The purpose of this study was to measure CBF and EEG during N2O administration in eight patients. A craniotomy was performed and CBF was measured in major brain arteries using a transit time Doppler flowmeter. ⋯ N2O administration in these patients also enhanced delta EEG activity and increased CBF. The slowing of EEG activity with N2O is temporally related to increases in CBF during normocapnia. Hypocapnia abolished the increase in CBF during N2O and attenuated the shift of EEG to delta activity.
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J Neurosurg Anesthesiol · Apr 1995
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of anesthetic techniques for awake intubation in neurosurgical patients.
Two different methods of achieving upper airway anesthesia for awake fiberoptic intubation were prospectively compared in patients undergoing surgery for cervical spine instability. Forty patients were randomized to either topical anesthesia or nerve block groups. Topical anesthesia patients were administered nebulized 4% lidocaine (approximately 20 ml) via the oropharynx plus a transtracheal injection of 4% lidocaine (3 ml). ⋯ Ten minutes later there was no difference for plasma lidocaine concentration between groups. No patients had evidence of seizures or neurologic change during the procedure. There was no difference in patient perception of discomfort during the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)
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J Neurosurg Anesthesiol · Apr 1995
Case ReportsPerforation and partial obstruction of an armored endotracheal tube.
Armored endotracheal tubes are often used during cases in which there is a risk of compromise of a polyvinylchloride tube with positioning of a patient's head. The authors describe a case in which partial airway obstruction and perforation of such a tube occurred as a result of biting by a patient. Ways to avoid this complication are discussed.
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J Neurosurg Anesthesiol · Apr 1995
Nitrous oxide increases cerebral blood flow velocity during pharmacologically induced EEG silence in humans.
We examined the effect of nitrous oxide on cerebral blood flow velocity (Vmca), arteriovenous oxygen content difference and cerebral use of glucose during propofol-induced electrical silence of the electroencephalogram (EEG) in 10 patients undergoing anesthesia for nonneurosurgical procedures. Anesthesia was induced with propofol 2.5 mg/kg, fentanyl 3 micrograms/kg (followed by an infusion of 2 micrograms/kg/h), vecuronium 0.1 mg/kg, and maintained with a propofol infusion (250-300 micrograms/kg/min) sufficient to induce EEG silence. A transcranial Doppler was used to measure the Vmca and a jugular bulb catheter was inserted for oxygen saturation and glucose use measurements. ⋯ Nitrous oxide increased Vmca (29 +/- 4 to 35 +/- 4 cm/s, p < 0.01), cerebral use of oxygen (166 +/- 13 to 190 +/- 12 vol%-cm/s, p < 0.05) and glucose (245 +/- 38 to 290 +/- 48 g%-cm/s, p < 0.05) by approximately 20%. Occasional bursts of EEG activity were observed in eight patients studied during the N2O stage. We conclude that in patients with propofol-induced isoelectric EEG, the increase seen in Vmca with the introduction of N2O is mainly due to cerebral stimulation and increase in cerebral metabolic rate.