Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Apr 1996
Clinical TrialBrain relaxation and cerebrospinal fluid pressure during craniotomy for resection of supratentorial mass lesions.
Neurosurgery can be complicated by the clinical situation commonly referred to as "tight brain," in which the brain presses against the inner table of the skull or protrudes through the craniotomy site. We report here a retrospective study of 32 patients who had undergone elective craniotomy for resection of supratentorial mass lesions. We determined the relationship between lumbar cerebrospinal fluid pressure (CSFP) and brain relaxation and whether brain relaxation varies with anesthetic technique. ⋯ We conclude that in patients undergoing elective craniotomy for resection of a supratentorial mass lesion, brain relaxation is not predictive of CSFP. Although CSFP values at the extremes of the observed distribution ( > 17 mm Hg or < 6 mm Hg) did correlate with brain relaxation, within the range of 6-17 mm Hg, CSFP did not predict brain relaxation. Additionally, the data from this study suggest that in patients undergoing elective craniotomy for resection of a supratentorial mass lesion, tight brain may occur with a lower frequency in patients receiving 0.5 MAC ISO or DES with 50% N2O than in patients receiving 1 MAC ISO or DES.
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J Neurosurg Anesthesiol · Apr 1996
Case ReportsPositioning a right atrial air aspiration catheter using transesophageal echocardiography.
The occurrence of venous air embolism (VAE) during neurosurgery in the sitting position is well documented. The optimal position of an air aspiration catheter appears to be with the catheter tip at the junction of the right atrium and superior vena cava (SVC). A number of localization techniques have been described, with the electrocardiographic guided technique being the most commonly employed. This case report describes the use of transesophageal echocardiography (TEE) for the precise and timely placement of a right atrial-SVC air aspiration catheter.
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J Neurosurg Anesthesiol · Apr 1996
Suppression of spinal and cortical somatosensory evoked potentials by desflurane anesthesia.
The effect of the volatile anesthetic desflurane on spinal and cortical somatosensory evoked potentials (SEPs) was examined in 11 Sprague-Dawley male rats. Platinum recording electrodes were placed stereotactically over the left somatosensory cortex and dorsal midline of the T11-12 spinal cord while the right posterior tibial nerve was stimulated at twice motor threshold. The effect of desflurane was examined at various concentrations ranging from 0.7 to 11.4% (2 MAC). ⋯ At 11.4% (2 MAC), the CSEPs were lost in all animals. Only one rat lost the SSEPs at the 2 MAC concentration of desflurane, indicating the resistance of the SSEPs to desflurane anesthesia. We conclude that desflurane anesthesia significantly alters the amplitude of SSEPs and CSEPs without a significant change in the peak latency.
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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.