Ignite Creation Date:
2024-05-05 @ 5:22 PM
Last Modification Date:
2024-10-26 @ 9:31 AM
Study NCT ID:
NCT00443807
Status:
COMPLETED
Last Update Posted:
2008-04-16
First Post:
2007-03-05
Brief Title:
EEG Monitoring to Assess Emergence From Neuroanesthesia
Sponsor:
University of Manitoba
Organization:
University of Manitoba
Study Overview
Official Title:
A Comparison of the EEGo and BIS Monitors to Assess Emergence From Neuroanesthesia
Status:
COMPLETED
Status Verified Date:
2008-04
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
A highly desired result in neuroanesthesia is a prompt controlled emergence following a neurosurgical procedure Considerable strides have been made in this direction with volatile anesthetic agents such as sevoflurane or desflurane administered in association with the narcotic remifentanil It is characteristic that patients will emerge within 5 to 10 minutes of cessation of these agents at the end of a neuroanesthetic However there are cases where emergence is delayed especially after periods of deep anesthesia for i cerebral protection with temporary clipping of cerebral aneurysms and ii with microvascular decompression for trigeminal neuralgia Deep levels of anesthesia are standard for these procedures in the posterior fossa which utilize motor evoked potentials to assess cranial nerve function In these cases EEG monitoring is standard Using the EEG to monitor emergence to aid its progress makes sense A monitor which could predict emergence in these patients would be valuable EEG monitoring engineered to provide this information is now available in the form of the EEGo This study is designed to test the hypothesis that the EEGo monitor will be superior to the BIS monitor to assess emergence following neuroanesthesia
Detailed Description:
Objective This study is designed to test the hypothesis that the EEGo monitor will be superior to the BIS monitor to assess emergence following neuroanesthesia The EEGo will be able to more accurately indicate emergence and direct therapy at the end of the operative procedure The EEGo will be superior because the raw EEG signal is processed using phase delay analysis with each patients raw EEG analyzed instead of a proprietary but generic signal processing approach on a linear scale as with the BIS monitor Phase delay analysis is a standard approach to display nonlinear signals A highly reproducible signal transition occurs from deep anesthesia to emergence It is this transition that permits acute assessment of emergence The ability to process the EEG and display phase delay plots in 50 msec is what makes the EEGo monitor attractive to acutely assess emergence from neuroanesthesia Accurate emergence will allow better anesthesia management
This pilot study will be done to assess a nonlinear EEG monitor EEGo to direct therapy and predict prompt emergence from neuroanesthesia where EEG monitoring is done in neurosurgical cases In our centre we routinely monitor the EEG SSEP andor MEP during temporary aneurysm clipping and during microvascular decompressive surgery It is just these cases where emergence can be delayed despite following standard neuroanesthesia techniques The EEGo processes the standard EEG signal by nonlinear analysis of the raw signal by 3 dimensional phase delay plots A cascade from a point attractor periodic attractor toroidal attractor to a 3-D chaotic attractor occurs from burst suppression to the awake state These resemble phase transitions and occur rapidly from one state to the next An analogy is the phase transition that occurs when water changes to ice and vice versa Monitoring these transitions should permit a rational approach to therapy during anesthesia emergence better predict emergence facilitate extubation based on the awake state allow titration of vasoactive agents during emergence to smooth hemodynamic control and permit more rapid emergence at end procedure The EEGo will be compared directly in real time to the bispectral BIS monitor re goal directed emergence If efficacy is shown with the EEGo a more formal comparison to BIS and clinical judgement will be studied
BIS monitoring can aid emergence in outpatient procedures both with time to wakening and time in the recovery room These results also impact on the cost of anesthetic drugs and OR and Recovery Room costs Work demonstrating accelerated emergence from desflurane with BIS do not highlight the manner in which the BIS directs the emergence The depth of anesthesia is adjusted to 50 - 60 ABU during maintenance and then emergence is tracked A specific BIS number to indicate emergence is not suggested In fact a correlation between the BIS in the awake state and with movement and eye opening appears poor with the emergence BIS usually being lower than the pre-induction BIS The BIS may also on occasion be very low during emergence - deemed artifactually so and in this work it is suggested that the raw EEG be observed to aid emergence It would seem that significant issues relate to intra and interpatient variability with this processed EEG signal Recent work suggests significant discrepancy of BIS signals between hemispheres and even recording from two sites in the same hemisphere In addition BIS correlates poorly with end-tidal desflurane and awake state
Thus it would seem that while the BIS can aid management of depth of anesthesia during maintenance it is not ideally suited to direct a facilitated emergence In contrast the EEGo monitor uses nonlinear analysis techniques to provide a visual output related to depth of anesthesia
This pilot study will be done to assess a nonlinear EEG monitor EEGo to direct therapy and predict prompt emergence from neuroanesthesia where EEG monitoring is done in neurosurgical cases In our centre we routinely monitor the EEG SSEP andor MEP during temporary aneurysm clipping and during microvascular decompressive surgery It is just these cases where emergence can be delayed despite following standard neuroanesthesia techniques The EEGo processes the standard EEG signal by nonlinear analysis of the raw signal by 3 dimensional phase delay plots A cascade from a point attractor periodic attractor toroidal attractor to a 3-D chaotic attractor occurs from burst suppression to the awake state These resemble phase transitions and occur rapidly from one state to the next An analogy is the phase transition that occurs when water changes to ice and vice versa Monitoring these transitions should permit a rational approach to therapy during anesthesia emergence better predict emergence facilitate extubation based on the awake state allow titration of vasoactive agents during emergence to smooth hemodynamic control and permit more rapid emergence at end procedure The EEGo will be compared directly in real time to the bispectral BIS monitor re goal directed emergence If efficacy is shown with the EEGo a more formal comparison to BIS and clinical judgement will be studied
BIS monitoring can aid emergence in outpatient procedures both with time to wakening and time in the recovery room These results also impact on the cost of anesthetic drugs and OR and Recovery Room costs Work demonstrating accelerated emergence from desflurane with BIS do not highlight the manner in which the BIS directs the emergence The depth of anesthesia is adjusted to 50 - 60 ABU during maintenance and then emergence is tracked A specific BIS number to indicate emergence is not suggested In fact a correlation between the BIS in the awake state and with movement and eye opening appears poor with the emergence BIS usually being lower than the pre-induction BIS The BIS may also on occasion be very low during emergence - deemed artifactually so and in this work it is suggested that the raw EEG be observed to aid emergence It would seem that significant issues relate to intra and interpatient variability with this processed EEG signal Recent work suggests significant discrepancy of BIS signals between hemispheres and even recording from two sites in the same hemisphere In addition BIS correlates poorly with end-tidal desflurane and awake state
Thus it would seem that while the BIS can aid management of depth of anesthesia during maintenance it is not ideally suited to direct a facilitated emergence In contrast the EEGo monitor uses nonlinear analysis techniques to provide a visual output related to depth of anesthesia
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None