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Intra-operative neuro-monitor during cardiac surgery. Intern 董正仁 2006.05.01. CNS complication during cardiac surgery. 6.1% of 2100 patients undergoing conventional CABG surgery evidence clinically apparent CNS injury postoperatively.
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Intra-operative neuro-monitor during cardiac surgery Intern 董正仁 2006.05.01
CNS complication during cardiac surgery • 6.1% of 2100 patients undergoing conventional CABG surgery evidence clinically apparent CNS injury postoperatively. • Over 50% of patients with either extra-cranial or intracranial atherosclerotic disease (ECAD, ICAD) -John M. Murkin <Perioperative Multimodality Neuromonitoring: An Overview> Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2004; 8: 167 - 171.
Intra-operative neuro-monitor modality • Mean arterial Pressure (MAP) • Transcranial Doppler (TCD) • Cerebral Oximetry • Near-infrared Reflectance Spectroscopy (NIRS) • Electroencephalogram (EEG) • Bispectral Index (BIS) Monitor • Auditory Evoked Potentials (AEP) -John M. Murkin <Perioperative Multimodality Neuromonitoring: An Overview> Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2004; 8: 167 - 171.
Mean arterial Pressure (MAP) • In patients undergoing CABG • MAP was maintained at > 80 mmHg • A lower incidence of morbidity, including stroke -Gold JP.< Improvement of outcomes after coronary artery bypass. A randomized trial comparing intraoperative high versus low mean arterial pressure.> Journal of Thoracic & Cardiovascular Surgery. 110(5):1302-11; discussion 1311-4, 1995 Nov.
Transcranial Doppler (TCD) • Ultrasound at frequencies of 2 MHz • Trans-temporal route above the zygomatic arch • ACA, MCA, PCA • Trans-orbital approach • Carotid artery • Sub-occipital route through the foramen magnum • BA, VA • Limitation: • small or absent trans-temporal windows or thick calvaria • to maintain the probe in the same position -Nousheh Saidi et al. <Applied Neuromonitoring in Cardiac Surgery: Patient Specific Management> Seminars in Cardiothoracic and Vascular Anesthesia, Mar 2005; 9: 17 - 23.
-Dennis D. Doblar <Intraoperative Transcranial Ultrasonic Monitoring for Cardiac and Vascular Surgery> Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2004; 8: 127 - 145.
High-intensity transient signals (HITS) caused by micro-emboli -Dennis D. Doblar <Intraoperative Transcranial Ultrasonic Monitoring for Cardiac and Vascular Surgery>-Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2004; 8: 127 - 145.
Transcranial Doppler (TCD) • Improvement and new-finding: 1. Distinguish between solid and gaseous emboli -Abu-Omar et al. <Solid and gaseous cerebral microembolization during off-pump, on-pump, and open cardiac surgery procedures > Journal of Thoracic and Cardiovascular Surgery ,127( 6) June, 2004 pp. 1759-1765
Improvement and new-finding 2. Leukocyte depletion filtration >intra-aortic filter 3. Cerebral emboli and adverse cerebral outcome might be related to the presence of aortic atheromatous disease in CABG 4. Modification of perfusionist intervention 5. Postoperatively, detect cerebral emboli after carotid endarterectomy triggered dextran anticoagulation • significant decrease in perioperative stroke -Nousheh Saidi and John M. Murkin <Applied Neuromonitoring in Cardiac Surgery: Patient Specific Management>Seminars in Cardiothoracic and Vascular Anesthesia, Mar 2005; 9: 17 - 23.
EEG • Requirement of a dedicated technician for placement of the electrodes • Subjective nature of interpretation • Electrical signal interference
Bi-spectral Index (BIS) Monitor • EEG-based monitor with dimensionless -Nousheh Saidi and John M. Murkin <Applied Neuromonitoring in Cardiac Surgery: Patient Specific Management > Seminars in Cardiothoracic and Vascular Anesthesia, Mar 2005; 9: 17 - 23.
BIS value • Active BIS monitoring of cardiac surgery is likely to significantly decrease the risk of intra-operative awareness and recall.
BIS • Use in cardiac anesthesia • Low BIS values may be related to cerebral ischemia • May used to detect cerebral embolic • Several case-report suggest that: • A change in the BIS values is specific not for cerebral infarction • But a BIS decrease may be the first indication of a serious cerebral event -Naureen Adam and Peter S. Sebel <BIS Monitoring: Awareness and Catastrophic Events> Seminars in Cardiothoracic and Vascular Anesthesia, Mar 2004; 8: 9 - 12.
Near-infrared Reflectance Spectroscopy (NIRS) • Cerebral Oximetry • Wavelength of 650~1100nm • Bi-hemispheric measure of cerebral regional oxygen saturation (rSO2) through the intact calvarium • A positive predictive value between low rSO2 and adverse CNS outcomes -John M. Murkin <Perioperative Multimodality Neuromonitoring: An Overview> Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2004; 8: 167 - 171.
NIRS • A randomized, blinded study of 198 CABG patients • rSO2 monitoring is associated with s significant decrease in combined major morbidities • Death • Stroke • Myocardiacl infarction • Prolonged ventilatory support • Renal failure -Nousheh Saidi and John M. Murkin <Applied Neuromonitoring in Cardiac Surgery: Patient Specific Management > Seminars in Cardiothoracic and Vascular Anesthesia, Mar 2005; 9: 17 - 23.
-Dimitri Novitzky <Reducing the Risk of Myocardial Revascularization: Relevance of Multimodal Brain Monitoring> Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2005; 9: 131 - 137.
-Dimitri Novitzky <Reducing the Risk of Myocardial Revascularization: Relevance of Multimodal Brain Monitoring> Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2005; 9: 131 - 137.
Auditory Evoked Potentials (AEP) • AEP assess specific areas of • Auditory nerve • Brainstem • Midbrain • Auditor cortices • In cardiac surgery: • Monitoring of cerebral hypothermia and the avoidance of excessive re-warming during CPB • Assessment of the functional integrity of the CNS -Rosendo A. Rodriguez <Human Auditory Evoked Potentials in the Assessment of Brain Function During Major Cardiovascular Surgery>Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2004; 8: 85 - 99.
-Rosendo A. Rodriguez <Human Auditory Evoked Potentials in the Assessment of Brain Function During Major Cardiovascular Surgery> Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2004; 8: 85 - 99.
Monitoring of Cerebral Hypothermia and re-warming • Extra-cranial sites may not reflect the temperature of the core brain • Hypothermia • the latency of BAEP ↑ • the amplitude of BAEP ↓ • these effects are reversible during re-warming • An objective indirect method for monitoring functional temperature changes in the core of the brain. -Rosendo A. Rodriguez <Human Auditory Evoked Potentials in the Assessment of Brain Function During Major Cardiovascular Surgery> Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2004; 8: 85 - 99.
Monitoring of Cerebral Hypothermia and rewarming -Rosendo A. Rodriguez <Human Auditory Evoked Potentials in the Assessment of Brain Function During Major Cardiovascular Surgery>Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2004; 8: 85 - 99.
Assessment of the functional integrity of the CNS -Rosendo A. Rodriguez <Human Auditory Evoked Potentials in the Assessment of Brain Function During Major Cardiovascular Surgery> Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2004; 8: 85 - 99.
Neuro-monitor Limitation • Highly regional • miss significant localized cerebral ischemia • Global in nature • relatively to regional ischemia • Multimodality CNS monitoring that incorporates different complementary technique is needed -John M. Murkin <Perioperative Multimodality Neuromonitoring: An Overview> Seminars in Cardiothoracic and Vascular Anesthesia, Jun 2004; 8: 167 - 171.
Take home massage • MAP • greater than 80 mmHg • TCD • to detect macro- or microemboli • Bispectral Index (BIS) • To detect cerebral ischemia • Cerebral Oximetry • for cerebral regional oxygen saturation (rSO2) • Auditory Evoked Potentials (AEP) • Monitoring of cerebral hypothermia and re-warming • Assessment of the functional integrity of the CNS
Near-infrared Reflectance Spectroscopy (NIRS) • Monitor rSO2 • Of the 98 patients receiving CABG, 54 in control group and 44 in intervention group • Intervention: • increasing perfusion pressure, pump flow,FiO2, Hct (if <20%), PaCO2 to >45mmHg • decrease temperature (if >37C) • Control: managed routinely • Significant shorting of length of stay -John M. Murkin <Perioperative Detection of Brain Oxygenation and Clinical Outcomes in Cardiac Surgery> Seminars in Cardiothoracic and Vascular Anesthesia, Mar 2004; 8: 13 - 14.
Auditory Evoked Potentials (AEP) • Early AEP from the auditory nerve and the brainstem (BASEP) • Middle-latency AEP from polystnaptic activity in the midbrain or diencephalic nuclei and the primary auditory cortex and adjacent areas Rosendo A. RodriguezHuman Auditory Evoked Potentials in the Assessment of Brain Function During Major Cardiovascular SurgerySeminars in Cardiothoracic and Vascular Anesthesia, Jun 2004; 8: 85 - 99.
Ziser A. Adir Y. Lavon H. Shupak A. Hyperbaric oxygen therapy for massive arterial air embolism during cardiac operations. [Journal Article] Journal of Thoracic & Cardiovascular Surgery. 117(4):818-21, 1999 Apr.
Abu-Omar et al. <Solid and gaseous cerebral microembolization during off-pump, on-pump, and open cardiac surgery procedures > Journal of Thoracic and Cardiovascular Surgery ,127( 6) June, 2004 pp. 1759-1765