Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Jan 1996
Comparative StudyA comparison of the electrophysiologic characteristics of EEG burst-suppression as produced by isoflurane, thiopental, etomidate, and propofol.
Electroencephalogram (EEG) burst-suppression can be produced with several anesthetic agents. Discussions of burst-suppression suggest that it has been viewed by many as a relatively uniform physiologic state independent of the agent used to produce it. This view may be an oversimplification. ⋯ The cortical versus subcortical comparison revealed, for all agents, greater peak-to-peak voltage and area under the curve in the subcortex. The data indicate that the electrophysiologic characteristics of burst-suppression vary among the four agents, with the possible exception of etomidate and propofol. The data suggest that the neurophysiologic states associated with burst-suppression produced by various anesthetics should not be assumed to be uniform.
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J Neurosurg Anesthesiol · Jan 1996
Case ReportsCerebral ischemia after venous air embolism in the absence of intracardiac defects.
Cerebral air embolism occurred in a patient undergoing posterior fossa surgery performed in the sitting position for acoustic neuroma removal. The patient experienced two episodes of venous air embolism, as evidenced by precordial Doppler, end-tidal carbon dioxide reduction, and oxygen desaturation. In both cases, air was aspirated from the central venous catheter; during the second episode there was arterial hypotension and electrocardiogram changes, and air bubbles were visualized in the cerebellar arteries. ⋯ Intracardiac septal defects were not detected by transesophageal echocardiography, and computerized tomography of the brain demonstrated multifocal discrete ischemic areas in the cerebral hemispheres. The patient died 6 days after surgery without having regained consciousness. This case appears to represent the occurrence of transpulmonary passage of venous air embolism.
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J Neurosurg Anesthesiol · Jan 1996
Case ReportsLimitations of jugular bulb oxyhemoglobin saturation without intracranial pressure monitoring in subarachnoid hemorrhage.
We report a case of subarachnoid hemorrhage in which, even after having obtained a normal jugular bulb oxyhemoglobin saturation, cerebrovenous desaturation developed, and brain death occurred. The limitations of jugular bulb oxyhemoglobin saturation without intracranial pressure monitoring are discussed. We conclude that if increased intracranial pressure is suspected, use of jugular bulb oxyhemoglobin saturation monitoring alone would appear to be substantially limited.
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J Neurosurg Anesthesiol · Jan 1996
Effect of desflurane anesthesia on transcortical motor evoked potentials.
The effect of the volatile anesthetic desflurane on motor evoked potentials was examined in male rats. Animals underwent cortical stimulation using small platinum ball stimulating electrodes secured on the motor cortex. To record evoked compound muscle action potentials (CMAPs), single-shock electrical stimulation was delivered to the forelimb representation of the motor cortex. ⋯ Although there was a decrease in heart rate, the results were not statistically significant (p = 0.03). No significant difference in the onset latency or the duration of the CMAP was noted at different concentrations of the anesthetic. We conclude that desflurane anesthesia significantly alters the amplitude of the muscle response evoked by motor cortex stimulation in experimental animals.