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MGH DACC Clinical Practices Committee. An Electroencephalogram Study of Induction and Recovery from Propofol Anesthesia July 7, 2005 PI: Brown CoPI: Walsh, Purdon, Mullaly, Kwo, Harrell, Williams, Dray, Bonmassar, Angelone, Hamalainen, Barlow, Matten. Issues for DACC.
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MGH DACC Clinical Practices Committee An Electroencephalogram Study of Induction and Recovery from Propofol Anesthesia July 7, 2005 PI: Brown CoPI: Walsh, Purdon, Mullaly, Kwo, Harrell, Williams, Dray, Bonmassar, Angelone, Hamalainen, Barlow, Matten
Issues for DACC • Permission to conduct EEG/propofol study • Identical to DACC-approved EEG/fMRI/propofol study, but with EEG only, no fMRI • Permission to implement protocol at the GCRC Bioimaging Core facility (CNY 149) as an offsite location
Overview • Protocol History • Research Background • Walk Through Protocol • Human Research Protection/ Safety
Protocol History • Similar to BIS/propofol protocol by Rosow/Kearse (1998) • Similar to EEG/fMRI/Anesthesia by Brown • IRB approved (1999-P-010748 MGH) • Reviewed by MGH DACC CPC • MGH Mallinckrodt GCRC (GAC)
EEG/propofol vs. EEG/fMRI/propofol • EEG only, no fMRI under anesthesia • Study conducted in standard clinical area • Airway management with bag-mask • ASA I Study Subjects ages 18-36 • Conducted in GCRC Bioimaging core • Meets requirements for off-site anesthesia • EEG source localization • Requires structural MRI in separate session
Clinical Obs., EEG, BIS Induction of Anesthesia Site Specific Changes in Neural Activity EEG Source Localization GABA-A, NMDA (?) Research Background
Somatosensory-Motor Exp’t: Early somatosensory peak, followed by motor response EEG Source Localization • Combine structural/conductivity information from anatomic MRI to “localize” auditory, somatosensory, and cognitive function • Faster time scale than fMRI, but spatial resolution lower w/ limited subcortical visibility
Our Objective To correlate simultaneous measurements of • electroencephalogram (EEG) • plasma levels of propofol • well-defined behavioral markers • changes in source localization during induction of and recovery from general anesthesia.
Walk Through Protocol • Study subject pre-anesthesia clinical assessment • Prior to study • GCRC White 13 • Induction and Recovery from Propofol • Study subject follow-up • Separate anatomic MRI scan (30 minutes)
Study Protocol: Clinical Assessment • Subject Recruitment • Healthy male and female volunteers • Ages 18-36 • Total 44 subjects recruited • ASA physical status I • Telephone Questionnaire • Pre-study Assessment (2 hours) • History and Physical Examination • Toxic Screen and Pregnancy Test (female subjects)
Study Protocol: Clinical Preparation • Toxic screen and pregnancy test • Standard Anesthesia Monitors: • ECG, BP cuff, pulse oximeter, capnogram • Additional Monitors: • EEG, arterial line • Airway Maintenance: • Bag mask • Phenylephrine to maintain BP • Additional Drugs: • bicitra, ondansetron
Study Protocol: Overview DIAGRAM W/ CONCENTRATION PROFILE
Equipment/ Supplies at CNY 149 • ACLS cart • Defibrillator • Anesthesia Cart • Airway equipment • Anesthesia Machine • O2 and Air (Wall and E-cylinders) • Monitors (FiO2, SaO2, EtCo2, ECG, NIBP, P1) • Laboratory Testing (urine pregnancy, tox screen, ABG) • iSTAT • EEG machine and electrodes • Routinely maintained by Biomedical Engineering
ACLS Cart, Defibrillator • PICTUR OF ACLS CART AND DEFIB
Anesthesia Cart and Anesthesia Machine • PICTURE OF ANESTHESIA CART AND ANESTHESIA MACHINE
O2 Supply: Wall + E-cylinders • PICTURE OF WALL AIR/02 AND E-CYLINDERS
Nursing Responsibilities • Page study Physician • Urine toxicity screen • Urine pregnancy test • ART line setup available • ABG sampling + analysis w/ iSTAT • Preparation of blood samples for storage (propofol)
Medical Staff Responsibilities • Clinical Anesthesiologist • care of study subject • PACU care • Study Anesthesiologist • organization and execution of study protocol • STANPUMP infusion
MLAEP, 4.0 ug/ml MLAEP, 0.0 ug/ml MLAEP, 2.0 ug/ml 1 1 1 0.5 0.5 0.5 P P a a 0 0 0 N b P N Amplitude (uV) a b -0.5 -0.5 -0.5 N N b a N -1 N -1 -1 a a -1.5 -1.5 -1.5 0 20 40 60 80 100 0 20 40 60 80 100 0 20 40 60 80 100 Post-stimulus latency (msec) Post-stimulus latency (msec) Post-stimulus latency (msec) Power Spectrum, 0.0 ug/ml Power Spectrum, 2.0 ug/ml Power Spectrum, 4.0 ug/ml 6000 6000 6000 5000 5000 5000 /Hz) 4000 4000 4000 2 3000 3000 3000 Power (uV 2000 2000 2000 1000 1000 1000 0 0 0 0 10 20 30 40 0 10 20 30 40 0 10 20 30 40 Frequency (Hz) Frequency (Hz) Frequency (Hz) EEG, 2.0 ug/ml EEG, 0.0 ug/ml EEG, 4.0 ug/ml 40 40 40 20 20 20 0 0 0 Amplitude (uV) -20 -20 -20 -40 -40 -40 0 1 2 3 4 0 1 2 3 4 0 1 2 3 4 Time (sec) Time (sec) Time (sec) Preliminary Studies MLAEP EEG Power Spectrum EEG time series Propofol: 0.0 ug/ml 2.0 ug/ml 4.0 ug/ml