INTRAOPERATIVE MONITORING (IOM) has been used to reduce cerebral and spinal cord injuries during the repair of thoracoabdominal aorta aneurysms (TAAAs). The risks of cerebral injury when the ascending aorta is repaired and of paraplegia when the descending thoracic aorta is involved have prompted the application of numerous techniques to measure blood flow, assess the balance of blood flow and metabolism, and warn of ischemia in order to prompt corrective measures.1,2 The neurologic risk varies with the portion and length of the aorta that is diseased.

J Thorac Cardiovasc Surg 2003;126:589-591 Thomas Yeh, Jr, Erle H. Austin, III, Aida Sehic and Harvey L. Edmonds, Jr neuromonitoring Rapid recognition and treatment of cerebral air embolism: the role ofhttp://jtcs.ctsnetjournals.org/cgi/content/full/126/2/589 located on the World Wide Web at: The online version of this article, along with updated information and services, is

The objective of this study was to compare retrograde with antegrade cerebral protection during acute aortic dissection repair using cerebral oximetry measurements. Fifty consecutive acute ascending aortic dissection repairs were analyzed. Cerebral oximetry data were collected for 41 of 50. Eight patients who had antegrade cerebral protection alone and 29 of 41 had retrograde cerebral protection alone. The per cent change in cerebral oximetry values during deep hypothermic circulatory arrest from baseline and from prearrest values was compared for the two groups using Student t test. The per cent change from baseline for the antegrade patients was: right 13.8 per cent and left -2.5 per cent; the per cent change from baseline for retrograde patients was: right 0.8 per cent and left 0.2 per cent (P values 0.216 and 0.725, respectively). The per cent change from the prearrest value for the antegrade patients was: right -12 per cent and left -15 per cent; the per cent change from prearrest for retrograde patients was: right -15 per cent and left -16 per cent (P values 0.514 and 0.956, respectively). No compelling evidence for an advantage to either antegrade or retrograde cerebral perfusion was detected. Further study with a focus on neurologic outcomes is warranted.

I thank Dr Hessel for his extensive critique. However, I fear that Dr Hessel has misunderstood my purpose. Because I discuss central nervous system (CNS) monitoring annually with dozens of cardiac anesthesia, surgical, perfusion, and neurophysiology groups, the editor asked me to assess the current status of these technologies. The editorial was not intended as either technology advocacy or a systematic review but rather a brief description and explanation of current usage patterns. Focus was concentrated on what is and not what should be.Because advocacy was not intended, Dr Hessel's concerns about my bias seem moot. However, in the interest of full disclosure, I earlier was the owner of a local neuromonitoring clinical service, Neuromonitoring Associates, which was purchased in 2005 by Philadelphia-based Surgical Monitoring Associates. Presently, I am a member of the speakers' bureaus for 2 Covidien companies, Aspect Medical and Somanetics Corporation, but I have no other financial interest in these or any other manufacturer of neuromonitoring devices or supplies.It is difficult to reliably determine current CNS monitoring modality acceptance. Its effective application often involves multiple clinical specialties, and the goals of monitoring vary widely among users. As a result, the interrogation of available professional society databases alone is inadequate. Therefore, I chose to adopt a widely used criterion, the standard of care. It was then adapted for a national audience based on placement statistics provided by the monitor manufacturers on their web sites. Using this approach, I determined that both cerebral oximetry and 1- to 4-channel forehead-based electroencephalographic devices have been placed in the majority of US adult cardiac centers. My conclusion was a simple statement of fact, which is verified easily by the reader.The second goal was to propose an explanation for this widespread adoption. In Dr Hessel's view, the adoption of CNS monitoring seems largely because of manufacturer marketing and hospital competition. Although these influences may be contributory, I respectfully disagree with his assertion. My visits with clinicians across the country have convinced me that their primary interest in CNS monitoring is improved quality of care. I believe that most clinicians ultimately adopt these technologies because of the extensive, generally positive peer-reviewed literature (>1,000 electroencephalographic and >600 cerebral oximeter articles) and favorable personal experience.I agree with Dr Hessel that, ideally, the widespread adoption of a new diagnostic or therapeutic modality should be based on multiple large-sample randomized clinical trials (RCTs). However, history suggests that, on occasion, the findings of these vaunted large-scale RCTs may be superseded by “unscientific” or non–evidence-based considerations.A case in point is pulse oximetry. The 1989 American Society of Anesthesiology House of Delegates mandate for pulse oximetry monitoring in every surgery involving general or regional anesthesia was not RCT based. Subsequently, in 1993, a 20,000+ patient RCT found no oximeter-related outcome improvement.1Moller J.T. Johannessen N.W. Espersen K. et al.Randomized evaluation of pulse oximetry in 20,802 patients; II Perioperative events and postoperative complications.Anesthesiology. 1993; 78: 445-453Crossref PubMed Scopus (307) Google Scholar In an accompanying editorial, Eichhorn2Eichhorn J.H. Pulse oximetry as a standard of practice in anesthesia.Anesthesiology. 1993; 78: 423-426Crossref PubMed Scopus (54) Google Scholar justified the mandate on the grounds that “It is reasonable to be influenced and accept more indirect indications when considering the complex multivariate epidemiologic investigations dealing with anesthetic outcome.” Universal acceptance of pulse oximetry suggests that most clinicians shared and continue to share this view.Presumably, this reasoning also applies to risk-free, noninvasive neuromonitoring modalities. For example, Vohra et al3Vohra H.A. Modi A. Ohri S.K. Does use of intra-operative cerebral regional oxygen saturation monitoring during cardiac surgery lead to improved clinical outcomes?.Interact Cardiovasc Thorac Surg. 2009; 9: 318-322Crossref PubMed Scopus (47) Google Scholar concluded their 488 article cardiac surgery cerebral oximetry literature review with the statement “Clinical benefit and lack of use-associated risk of injury at a modest expense support the use of rSO2 monitoring routinely in patients undergoing cardiac surgery.”As testimony to the current clinical acceptance and value of cerebral oximetry for cardiac surgery, Professor Edwin G. Avery IV, MD, Chief, Division of Cardiac Anesthesia, Case Western Reserve University School of Medicine, summarized a recent Duke Clinical Research Institute query of the Society of Thoracic Surgeons (STS) adult cardiac surgery database.4Avery E.G. Cerebral oximetry is frequently a “First Alert” indicator of adverse outcomes.http://www.somanetics.com/images/stories/pdfs/white-paper-series.pdfGoogle Scholar It examined more than 36,000 cases from 2008 and 2009 that contained cerebral oximetry performance measures. The query determined that in 23% of the surgeries, cerebral oximetry provided the first alert of a potentially injurious physiologic imbalance which led to altered patient management.In summary, I believe that the current adoption patterns for both cerebral oximetry and a forehead-based electroencephalogram appear to be based on an extensive literature and positive experience. In support of my view, Murkin recently concluded that the cerebral oximetry adoption controversy has become “standard of care for routine cardiopulmonary bypass versus evolving standard for selective cerebral perfusion.”5Murkin J.M. NIRS: A standard of care for CPB vs. an evolving standard for selective cerebral perfusion?.J Extracorpor Technol. 2009; 41: P11-P14PubMed Google Scholar I thank Dr Hessel for his extensive critique. However, I fear that Dr Hessel has misunderstood my purpose. Because I discuss central nervous system (CNS) monitoring annually with dozens of cardiac anesthesia, surgical, perfusion, and neurophysiology groups, the editor asked me to assess the current status of these technologies. The editorial was not intended as either technology advocacy or a systematic review but rather a brief description and explanation of current usage patterns. Focus was concentrated on what is and not what should be. Because advocacy was not intended, Dr Hessel's concerns about my bias seem moot. However, in the interest of full disclosure, I earlier was the owner of a local neuromonitoring clinical service, Neuromonitoring Associates, which was purchased in 2005 by Philadelphia-based Surgical Monitoring Associates. Presently, I am a member of the speakers' bureaus for 2 Covidien companies, Aspect Medical and Somanetics Corporation, but I have no other financial interest in these or any other manufacturer of neuromonitoring devices or supplies. It is difficult to reliably determine current CNS monitoring modality acceptance. Its effective application often involves multiple clinical specialties, and the goals of monitoring vary widely among users. As a result, the interrogation of available professional society databases alone is inadequate. Therefore, I chose to adopt a widely used criterion, the standard of care. It was then adapted for a national audience based on placement statistics provided by the monitor manufacturers on their web sites. Using this approach, I determined that both cerebral oximetry and 1- to 4-channel forehead-based electroencephalographic devices have been placed in the majority of US adult cardiac centers. My conclusion was a simple statement of fact, which is verified easily by the reader. The second goal was to propose an explanation for this widespread adoption. In Dr Hessel's view, the adoption of CNS monitoring seems largely because of manufacturer marketing and hospital competition. Although these influences may be contributory, I respectfully disagree with his assertion. My visits with clinicians across the country have convinced me that their primary interest in CNS monitoring is improved quality of care. I believe that most clinicians ultimately adopt these technologies because of the extensive, generally positive peer-reviewed literature (>1,000 electroencephalographic and >600 cerebral oximeter articles) and favorable personal experience. I agree with Dr Hessel that, ideally, the widespread adoption of a new diagnostic or therapeutic modality should be based on multiple large-sample randomized clinical trials (RCTs). However, history suggests that, on occasion, the findings of these vaunted large-scale RCTs may be superseded by “unscientific” or non–evidence-based considerations. A case in point is pulse oximetry. The 1989 American Society of Anesthesiology House of Delegates mandate for pulse oximetry monitoring in every surgery involving general or regional anesthesia was not RCT based. Subsequently, in 1993, a 20,000+ patient RCT found no oximeter-related outcome improvement.1Moller J.T. Johannessen N.W. Espersen K. et al.Randomized evaluation of pulse oximetry in 20,802 patients; II Perioperative events and postoperative complications.Anesthesiology. 1993; 78: 445-453Crossref PubMed Scopus (307) Google Scholar In an accompanying editorial, Eichhorn2Eichhorn J.H. Pulse oximetry as a standard of practice in anesthesia.Anesthesiology. 1993; 78: 423-426Crossref PubMed Scopus (54) Google Scholar justified the mandate on the grounds that “It is reasonable to be influenced and accept more indirect indications when considering the complex multivariate epidemiologic investigations dealing with anesthetic outcome.” Universal acceptance of pulse oximetry suggests that most clinicians shared and continue to share this view. Presumably, this reasoning also applies to risk-free, noninvasive neuromonitoring modalities. For example, Vohra et al3Vohra H.A. Modi A. Ohri S.K. Does use of intra-operative cerebral regional oxygen saturation monitoring during cardiac surgery lead to improved clinical outcomes?.Interact Cardiovasc Thorac Surg. 2009; 9: 318-322Crossref PubMed Scopus (47) Google Scholar concluded their 488 article cardiac surgery cerebral oximetry literature review with the statement “Clinical benefit and lack of use-associated risk of injury at a modest expense support the use of rSO2 monitoring routinely in patients undergoing cardiac surgery.” As testimony to the current clinical acceptance and value of cerebral oximetry for cardiac surgery, Professor Edwin G. Avery IV, MD, Chief, Division of Cardiac Anesthesia, Case Western Reserve University School of Medicine, summarized a recent Duke Clinical Research Institute query of the Society of Thoracic Surgeons (STS) adult cardiac surgery database.4Avery E.G. Cerebral oximetry is frequently a “First Alert” indicator of adverse outcomes.http://www.somanetics.com/images/stories/pdfs/white-paper-series.pdfGoogle Scholar It examined more than 36,000 cases from 2008 and 2009 that contained cerebral oximetry performance measures. The query determined that in 23% of the surgeries, cerebral oximetry provided the first alert of a potentially injurious physiologic imbalance which led to altered patient management. In summary, I believe that the current adoption patterns for both cerebral oximetry and a forehead-based electroencephalogram appear to be based on an extensive literature and positive experience. In support of my view, Murkin recently concluded that the cerebral oximetry adoption controversy has become “standard of care for routine cardiopulmonary bypass versus evolving standard for selective cerebral perfusion.”5Murkin J.M. NIRS: A standard of care for CPB vs. an evolving standard for selective cerebral perfusion?.J Extracorpor Technol. 2009; 41: P11-P14PubMed Google Scholar CNS Monitoring: The Current Weak State of the EvidenceJournal of Cardiothoracic and Vascular AnesthesiaVol. 25Issue 4PreviewI was disappointed and disturbed by the editorial published in the August issue of the Journal of Cardiothoracic and Vascular Anesthesia written by Edmonds on the standard of care for central nervous system monitoring during cardiac surgery.1 I believe this editorial was biased and misleading and did not accurately reflect the current state and strength (actually weakness) of the evidence in this matter. Full-Text PDF

in thisissue of JEVT is noteworthy for its use ofnoninvasive near-infrared reflectance spec-troscopy (NIRS) to detect spinal cord ische-mia during a staged hybrid thoracoabdominalaortic aneurysm repair. There is a clear needfor improved spinal cord monitoring duringthese procedures. Direct electrophysiologicalmonitoring of the descending motor path-ways appears to be beneficial, but the tech-nique has limitations. In addition to itstechnical complexity and constraints on an-esthetic management, both false positive andnegative findings have been reported.

The American Society of Neurophysiologic Monitoring (ASNM) and American Society of Neuroimaging (ASN) Guidelines Committees formed a joint task force and developed guidelines to assist in the use of transcranial Doppler (TCD) monitoring in the surgical and intensive care settings. Specifically, these guidelines: (1) delineate the objectives of TCD monitoring; (2) characterize the responsibilities and behaviors of the sonographer during monitoring; (3) describe methodological and ethical issues uniquely relevant to monitoring. The ASNM and ASN strongly support the positions that (1) acquisition and interpretation of intraoperative TCD ultrasonograms be performed by qualified individuals, (2) service providers define their diagnostic criteria and develop on-going self-validation programs of these performance criteria in their practices. We agree with the guidelines of other professional societies regarding the technical and professional qualifications of individuals responsible for TCD signal acquisition and interpretation (Class III evidence, Type C recommendation). On the basis of current clinical literature and scientific evidence, TCD monitoring is an established monitoring modality for the: (1) assessment of cerebral vasomotor reactivity and autoregulation; (2) documentation of the circle of Willis functional status; (3) identification of cerebral hypo- and hyperperfusion, recanalization and re-occlusion; and (4) detection of cerebral emboli (Class II and III evidence, Type B recommendation).

THE ARTICLE BY Baulig et al1Baulig W. Siefert B. Schmid E.R. et al.Comparability of spectral entropy and bispectral index electroencephalography in coronary artery bypass graft surgery.J Cardiothorac Vasc Anes. 2010; 24: 544-549Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar in this issue compares the performance of 2 quantitative electroencephalographic (EEG) monitors during coronary artery bypass graft (CABG) surgery. Typical of many neuromonitoring articles, it focuses on the process (ie, monitor A seems to perform differently from monitor B) instead of the influence of technology on patient outcome or cost-effectiveness. Historically, the dearth of outcome-oriented studies led many cautious and appropriately skeptical anesthesiologists to only hesitatingly use central nervous system monitoring for cardiac and major vascular surgical procedures. More recently, outcome studies have begun to appear. Thus, now seems to be an appropriate time to update the neuromonitoring status for cardiac and vascular surgery. The legal definition of "standard of care" is care given by the average prudent provider in a given locality.2Murkin J.M. NIRS: A standard of care for CPB vs. an evolving standard for selective cerebral perfusion?.J Extracorpor Technol. 2009; 41: P11-P14PubMed Google Scholar By this definition, a national standard of care designation for a new technology may be justified by the magnitude of its country-wide adoption rate. The application of some neuromonitoring technologies, such as multichannel traditional EEG and sensory or motor-evoked potentials, requires extensive specialized training and constant vigilance. As a consequence, their direct use by anesthesia providers generally is inappropriate and falls outside anesthesia provider standard of care consideration. In contrast, 3 technologies are suitable for use directly by anesthesiologists. These modalities are 1- or 2-channel quantitative EEG (QEEG), noninvasive regional oxygen saturation (rSO2) measured by near-infrared spectroscopy and large artery cerebral blood flow velocity assessed by transcranial (TCD) or carotid (CD) Doppler ultrasound. For QEEG, the sole outcome metric examined prospectively has been the incidence of explicit recall of intraoperative events. A single, large-sample, multicenter prospective trial involving adult cardiac and noncardiac surgery patients found that the use of 1 proprietary QEEG index, the bispectral index (BIS; Aspect Medical Systems/Covidien Inc, Norwood, MA) significantly reduced the risk of intraoperative awareness by 82%.3Myles P.S. Leslie K. McNeil J. et al.Bispectral index monitoring to prevent awareness during anaesthesia The B-Aware randomized controlled trial.Lancet. 2004; 363: 1757-1763Abstract Full Text Full Text PDF PubMed Scopus (916) Google Scholar A subsequent meta-analysis of controlled outcome studies concluded that "BIS could reduce the incidence of perioperative recall in surgical patients with a high risk of awareness."4Punjasawadwong Y. Boonjeungmonkol H.N. Phongchiewboon A. Bispectral index for improving anesthetic delivery and postoperative recovery.Cochrane Database Syst Rev. 2007; 4: CD3843Google Scholar At present, the BIS technology is installed in three quarters of both cardiac and noncardiac operating rooms in the United States.5http://bis.doctorevidence.com/openportal/Google Scholar There are 4 prospective small outcome studies involving rSO2 monitoring, 3 of which had positive findings. All studies used 1 device, the INVOS 5100 4-channel monitor (Somanetics Corporation, Troy, MI). Three of the trials focused on CABG surgery,6Murkin J.M. Adams S.J. Novick R.J. et al.Monitoring brain oxygen saturation during coronary artery bypass surgery: A randomized, prospective study.Anesth Analg. 2007; 104: 51-58Crossref PubMed Scopus (631) Google Scholar, 7Baker R.A. Knight J.L. The OXICAB Trial: Cerebral oximetry in adult cardiac surgical patients.J Extracorpor Technol. 2006; 8 (abstr): 77Google Scholar, 8Slater J.P. Guarino T. Stack J. et al.Cerebral oxygen desaturation predicts cognitive decline and longer hospital stay after cardiac surgery.Ann Thorac Surg. 2009; 87: 36-45Abstract Full Text Full Text PDF PubMed Scopus (471) Google Scholar whereas the fourth studied geriatric patients undergoing major noncardiac surgery.9Casati A. Fanelli G. Pietropaoli P. et al.Continuous monitoring of cerebral oxygen saturation in elderly patients undergoing major abdominal surgery minimizes brain exposure to potential hypoxia.Anesth Analg. 2005; 101: 740-747Crossref PubMed Scopus (279) Google Scholar The studies are not readily comparable because of differing methodologies and outcome measures. The study of Murkin et al6Murkin J.M. Adams S.J. Novick R.J. et al.Monitoring brain oxygen saturation during coronary artery bypass surgery: A randomized, prospective study.Anesth Analg. 2007; 104: 51-58Crossref PubMed Scopus (631) Google Scholar is especially noteworthy because it used a specific testable hypothesis and a thoroughly described standardized intervention algorithm10Denault A. Deschamps A. Murkin J.M. A proposed algorithm for the intraoperative use of cerebral near-infrared spectroscopy.Semin Cardiothorac Vasc Anesth. 2007; 11: 274-281PubMed Google Scholar and relied on robust outcome measures readily obtainable at all hospitals. Murkin et al's study is important in part because the outcome measures involved all vital organ function and not just an exclusive focus on brain function. This approach was derived from the study hypothesis that benefits of improved oxygen balance would not be limited to the brain. The results indicated that the intervention protocol was followed carefully and aggressively in all experimental group patients. A major rSO2 decline >25% below the preoperative baseline (ie, >150 minute-%) was associated with a significant increase in the Major Organ Morbidity and Mortality Index.11Shroyer A.L. Coombs L.P. Peterson E.D. et al.The Society of Thoracic Surgeons: 30-day operative mortality and morbidity risk models.Ann Thorac Surg. 2003; 75: 1856-1864Abstract Full Text Full Text PDF PubMed Scopus (511) Google Scholar Brain rSO2 monitoring significantly reduced the Major Organ Morbidity and Mortality Index, the need for postoperative mechanical ventilation, and the length of hospital stay. An as-yet unpublished independent economic analysis of the Murkin data by the present author has revealed that direct hospital savings exceeded cerebral oxygen monitoring cost by a factor of 10 in these normal-risk CABG patients. The "negative" study of Slater et al8Slater J.P. Guarino T. Stack J. et al.Cerebral oxygen desaturation predicts cognitive decline and longer hospital stay after cardiac surgery.Ann Thorac Surg. 2009; 87: 36-45Abstract Full Text Full Text PDF PubMed Scopus (471) Google Scholar also requires comment. The primary outcome measure, neurocognitive decline, is problematic because it is not standardized, it is difficult and expensive to measure, and it is not part of routine clinical management. Furthermore, its clinical and socioeconomic significance is controversial. Nevertheless, in agreement with Murkin et al, this study observed the adverse effects of major brain oxygen imbalance. Patients with >50 minute % rSO2 decline below the 50% saturation threshold exhibited significantly more severe postoperative cognitive decline and a higher incidence of prolonged hospital stay. The "negative" finding was that the group with INVOS-guided interventions experienced the same magnitude of cognitive decline as the control group. However, in contrast to Murkin et al,6Murkin J.M. Adams S.J. Novick R.J. et al.Monitoring brain oxygen saturation during coronary artery bypass surgery: A randomized, prospective study.Anesth Analg. 2007; 104: 51-58Crossref PubMed Scopus (631) Google Scholar the authors described poor intervention protocol compliance among the investigators such that the desaturation magnitude was the same in the control and treatment groups. This fundamental shortcoming suggests that the negativity descriptor should apply to study conduct rather than the effectiveness of rSO2 monitoring. In addition to these prospective studies, there is a large number of positive retrospective and case-controlled outcome studies, encompassing thousands of patients, which involved rSO2 monitoring in adult and pediatric cardiac or vascular surgery.12Goldman S.M. Sutter F.P. Ferdinand F. et al.Optimizing intraoperative cerebral oxygen delivery using noninvasive cerebral oximetry decreases the incidence of stroke for cardiac surgical patients.Heart Surg Forum. 2009; 7: E376-E381Crossref Scopus (196) Google Scholar, 13Moritz S. Kasprazak P. Arlt M. et al.Accuracy of cerebral monitoring in detecting cerebral ischemia during carotid endarterectomy.Anesthesiology. 2007; 107: 563-569Crossref PubMed Scopus (255) Google Scholar, 14Schön J. Serien V. Hanke T. et al.Cerebral oxygen saturation monitoring in on-pump cardiac surgery—A 1 year experience.Appl Cardiopulm Pathophysiol. 2009; 13: 243-252Google Scholar, 15Olsson C. Thelin S. Regional cerebral saturation monitoring with near-infrared spectroscopy during selective antegrade cerebral perfusion: diagnostic performance and relationship to postoperative outcome.J Thorac Cardiovasc Surg. 2006; 131: 374-379Google Scholar, 16Hong S.W. Shim J.K. Choi Y.S. et al.Prediction of cognitive dysfunction and patients' outcome following valvular heart surgery and the role of cerebral oximetry.Eur J Cardiothorac Surg. 2008; 33: 560-566Crossref PubMed Scopus (84) Google Scholar, 17Schön J. Serien V. Heinze H. et al.Association between cerebral desaturation and an increased risk of stroke in patients undergoing deep hypothermic circulatory arrest for cardiothoracic surgery.Appl Cardiopulm Pathphysiol. 2009; 13: 201-207Google Scholar This published evidence apparently has convinced a large majority of pediatric cardiac anesthesiologists of the benefit of perioperative rSO2 monitoring.18Tweddell J.S. Ghanaymem N.S. Hoffman G.M. Pro: NIRS is "Standard of Care" for postoperative management.Semin Thorac Cardiovasc Surg Pediatr Card Surg Annual. 2010; 13: 44-50Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar Currently, more than 80% of pediatric cardiac centers use this modality during and after surgery.19Wernovsky G. Ghanayem N. Ohye R.C. et al.Hypoplastic left heart syndrome: consensus and controversies in 2007.Cardiol Young. 2007; 17: 75-86PubMed Google Scholar Similarly, the majority of high-volume centers involved in adult aortic arch surgery have adopted rSO2 monitoring.2Murkin J.M. NIRS: A standard of care for CPB vs. an evolving standard for selective cerebral perfusion?.J Extracorpor Technol. 2009; 41: P11-P14PubMed Google Scholar Because of this growing evidence, rSO2 monitoring may have achieved national standard of care status for adult cardiac or carotid artery surgery.2Murkin J.M. NIRS: A standard of care for CPB vs. an evolving standard for selective cerebral perfusion?.J Extracorpor Technol. 2009; 41: P11-P14PubMed Google Scholar Manufacturer data on cerebral oximeter adoption indicate that these devices are installed in 50+% of US adult cardiac centers including two-thirds of the US News & World Report "top 50" institutions.20http://www.somanetics.com/invos-system/adult-surgery-icuGoogle Scholar The rSO2 application pattern varies markedly among adoptive adult cardiac centers. Although some institutions use rSO2 monitoring in all on-pump and off-pump21Mortiz S. Rochon J. Vökel S. et al.Determinants of cerebral oximetry in patients undergoing off-pump coronary artery bypass grafting: An observational study.Eur J Anaesthesiol. 2010; 27: 542-549PubMed Google Scholar cardiac surgery, others limit its use to variably defined "high-risk" cases. The selective approach appears to rely on published risk predictors.22Likosky D.S. Leavitt B.J. Marrin C.A.S. et al.Intra- and postoperative predictors of stroke after coronary artery bypass grafting.Ann Thorac Surg. 2003; 76: 428-435Abstract Full Text Full Text PDF PubMed Scopus (92) Google Scholar However, such studies typically use regression models to predict stroke occurrence in study cohorts that meet specific selection criteria. Data are not available that would permit infallible stroke prediction in individual patients. Indeed, an often-cited prospective predictive study22Likosky D.S. Leavitt B.J. Marrin C.A.S. et al.Intra- and postoperative predictors of stroke after coronary artery bypass grafting.Ann Thorac Surg. 2003; 76: 428-435Abstract Full Text Full Text PDF PubMed Scopus (92) Google Scholar emphasized that the high-stroke-risk cohort accounted for only one-quarter of all strokes within a very large multicenter CABG surgery population. There seems to be no unimpeachable justification for the selective use of this technology. Two small prospective outcome studies are available for TCD monitoring. Naylor et al23Naylor A.R. Hayes P.D. Allroggen H. et al.Reducing the risk of carotid surgery: A 7-year audit of the role of monitoring and quality control assessment.J Vasc Surg. 2000; 32: 750-759Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar found that TCD-directed patient management during and immediately after carotid endarterectomy completely prevented embolic brain injury. Estrera et al24Estrera A.L. Garami Z. Miller III, C.C. et al.Cerebral monitoring with transcranial Doppler ultrasonography improves neurologic outcome during repairs of acute type A aortic dissection.J Thorac Cardiovasc Surg. 2005; 129: 277-285Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar observed that TCD-guided cerebral perfusion management during acute aortic dissection repair reduced the incidence of postoperative brain injury from 52% to 10%. In addition, a retrospective study from the present author's group25Edmonds Jr, H.L. Protective effect of neuromonitoring during cardiac surgery.Ann N Y Acad Sci. 2005; 1053: 12-19Crossref PubMed Scopus (64) Google Scholar described the role of TCD-influenced perfusion management in an 11-fold reduction in ultrasonic cerebral embolic signals. The emboli reduction was associated with significant improvements in clinical outcome and hospital cost reduction. These benefits of TCD-verified emboli reduction were confirmed by other investigators using CD monitoring.26Hammon J.W. Stump D.A. Butterworth J.F. et al.Single crossclamp improves 6-month cognitive outcome in high-risk coronary bypass patients: The effect of reduced aortic manipulation.J Thorac Cardiovasc Surg. 2006; 131: 114-121Abstract Full Text Full Text PDF PubMed Scopus (95) Google Scholar Despite the apparent outcome benefits, TCD monitoring seems to be used only infrequently in cardiac, aortic, or carotid surgery. There are several reasons for this limited use. First, hyperostosis of the thin temporal bone and/or intracranial vascular disease may preclude monitoring in more than 10% of cardiac/aortic/carotid surgery patients. Second, obtaining and maintaining a useful ultrasound signal require specialized training, continuing practice, persistence, and careful vigilance during surgery. In the future, CD monitoring may offer an attractive alternative to TCD for cardiac surgery. As typified by the study of Hammon et al,26Hammon J.W. Stump D.A. Butterworth J.F. et al.Single crossclamp improves 6-month cognitive outcome in high-risk coronary bypass patients: The effect of reduced aortic manipulation.J Thorac Cardiovasc Surg. 2006; 131: 114-121Abstract Full Text Full Text PDF PubMed Scopus (95) Google Scholar CD can be used in all patients and requires only minimal training. It gives continuous information on a sudden change in blood flow to the brain and a semiquantitative estimate of embolic material flowing to the anterior cerebral circulation. Tomorrow will likely bring an emphasis shift for the role for QEEG monitoring as well as its integration with rSO2. Recent studies have raised issues about the potentially deleterious effects of prolonged anesthesia in elderly patients, particularly those undergoing cardiac and major vascular procedures.27Cotrell J.E. We care, therefore we are: Anesthesia-related morbidity and mortality.Anesthesiology. 2008; 109: 377-388Crossref PubMed Scopus (16) Google Scholar Because of these growing concerns, the QEEG indices are being used increasingly to identify excessive hypnosis and both its clinical and economic consequences.28Chiu C.L. Ong G. Majid A.A. Impact of bispectral index monitoring on propofol administration in patients undergoing cardiopulmonary bypass.Anaesth Intens Care. 2007; 35: 342-347PubMed Google Scholar In addition, the recent introduction of bilateral QEEG monitors29Pomfrett C.J.D. Dolling S. Anders N.R.K. et al.Delta sleep-inducing peptide alters bispectral index, the electroencephalogram and heart rate variability when used as an adjunct to isoflurane anaesthesia.Eur J Anaesthesiol. 2009; 26: 128-134Crossref PubMed Scopus (6) Google Scholar enables the detection of hemispheric neuronal suppression as a consequence of global or regional hypoperfusion.30Saager L. Greenwald S.D. Kelley S.D. et al.Hospital stay and mortality are increased by a "triple low" of blood pressure, BIS and anesthetic level.Anesthesiology. 2009; 114 (abstr): A6Google Scholar The coming integration of QEEG indices with rSO2 will help overcome an important limitation of each technology. A decline in any of the proprietary QEEG measures signifies suppression of cortical synaptic activity, but its cause is undefined. Thus, it can be difficult or impossible to rapidly and confidently distinguish hypothermia or excessive hypnosis from regional hypoperfusion or hypoxia. This distinction is facilitated with the addition of the rSO2 metric. A QEEG decrease without an accompanying rSO2 decline suggests an increased hypnotic effect or cold-induced synaptic suppression. Parallel reductions typically indicate the development of a potentially injurious cerebral physiologic imbalance. Similarly, QEEG declines accompanying an rSO2 decrease highlight the seriousness of the predominantly venous microcirculatory oxygen imbalance. Alternatively, the absence of QEEG change identifies successful brain compensation for inadequate oxygen supply through improved extraction. Ultimate integration of these modalities may be anticipated to further enhance their clinical acceptance and the quality of patient care. Comparison of Spectral Entropy and Bispectral Index Electroencephalography in Coronary Artery Bypass Graft SurgeryJournal of Cardiothoracic and Vascular AnesthesiaVol. 24Issue 4PreviewThe study's aim was to compare response entropy (RE) and state entropy (SE) with bispectral index (BIS) electroencephalography (EEG) as an alternative cerebral monitoring tool in patients scheduled for coronary artery bypass graft surgery. Full-Text PDF CNS Monitoring: The Current Weak State of the EvidenceJournal of Cardiothoracic and Vascular AnesthesiaVol. 25Issue 4PreviewI was disappointed and disturbed by the editorial published in the August issue of the Journal of Cardiothoracic and Vascular Anesthesia written by Edmonds on the standard of care for central nervous system monitoring during cardiac surgery.1 I believe this editorial was biased and misleading and did not accurately reflect the current state and strength (actually weakness) of the evidence in this matter. Full-Text PDF

BACKGROUND CONTEXT:Electroencephalography (EEG) is one of the oldest and most commonly utilized modalities for intraoperative neuromonitoring. Historically, interest in the EEG patterns associated with anesthesia is as old as the discovery of the EEG itself. The evolution of its intraoperative use was also expanded to include monitoring for assessing cortical perfusion and oxygenation during a variety of vascular, cardiac, and neurosurgical procedures. Furthermore, a number of quantitative or computer-processed algorithms have also been developed to aid in its visual representation and interpretation. The primary clinical outcomes for which modern EEG technology has made significant intraoperative contributions include: (1) recognizing and/or preventing perioperative ischemic insults, and (2) monitoring of brain function for anesthetic drug administration in order to determine depth of anesthesia (and level of consciousness), including the tailoring of drug levels to achieve a predefined neural effect (e.g., burst suppression). While the accelerated development of microprocessor technologies has fostered an extraordinarily rapid growth in the use of intraoperative EEG, there is still no universal adoption of a monitoring technique(s) or of criteria for its neural end-point(s) by anesthesiologists, surgeons, neurologists, and neurophysiologists. One of the most important limitations to routine intraoperative use of EEG may be the lack of standardization of methods, alarm criteria, and recommendations related to its application. Lastly, refinements in technology and signal processing can be expected to advance the usefulness of the intraoperative EEG for both anesthetic and surgical management of patients.OBJECTIVE:This paper is the position statement of the American Society of Neurophysiological Monitoring. It is the practice guidelines for the intraoperative use of raw (analog and digital) and quantitative EEG.METHODS:The following recommendations are based on trends in the current scientific and clinical literature and meetings, guidelines published by other organizations, expert opinion, and public review by the members of the American Society of Neurophysiological Monitoring. This document may not include all possible methodologies and interpretative criteria, nor do the authors and their sponsor intentionally exclude any new alternatives.RESULTS:The use of the techniques reviewed in these guidelines may reduce perioperative neurological morbidity and mortality.CONCLUSIONS:This position paper summarizes commonly used protocols for recording and interpreting the intraoperative use of EEG. Furthermore, the American Society of Neurophysiological Monitoring recognizes this as primarily an educational service.

In view of the existing controversy concerning the best perfusion technique during deep hypothermic circulatory arrest (DHCA) for neonatal heart operations, we examined intraoperative rSO2 to help define an optimal interval for an intermittent antegrade cerebral perfusion (IACP) strategy. Records of patients undergoing stage 1 palliation (S1P) and repair of total anomalous pulmonary venous return (rTAPVR) from 1996 to 2004 were reviewed. A total of 16 patients were identified (11 S1P, 5 rTAPVR) with complete data and long periods of DHCA. A decline in rSO2 of either 20% or below a value of 50 was considered significant. The rSO2 for all patients was evaluated after 5, 10, 15, and 20 minutes of DHCA for significant cerebral desaturation. The average rSO2 at the start of DHCA ranged from 45 to 89 for S1P and 35-86 for rTAPVR. Significant cerebral desaturation was observed in 25%-31% of patients after 5 minutes; 42%-44% of patients after 10 minutes; 58%-69% after 15 minutes; and 75%-83% after 20 minutes. Each neonate has a unique baseline cerebral saturation. Also, the response to DHCA varies among subjects as the rate of decrease of rSO2 was not uniform. Universally applying the same interval after which to perfuse the brain permits significant cerebral desaturation in a large percentage of patients. Cerebral oximetry may provide a guide for developing an individualized cerebral perfusion strategy.

Acta Anaesthesiologica ScandinavicaVolume 37, Issue s100 p. 102-104 Anesthetic adequacy, surface EMG and quantitated EEG HL. Edmonds Ph.D., Corresponding Author HL. Edmonds Ph.D. Departments of Anesthesiology, University of Louisville, Louisville, Kentucky, USAProfessor & Director of Research Department of Anesthesiology School of Medicine University of Louisville Louisville, Kentucky 40292 U.S.A.Search for more papers by this authorA. Yli–Hankala, A. Yli–Hankala Departments of Anesthesiology, University of Louisville, Louisville, Kentucky, USASearch for more papers by this authorMR Heine, MR Heine Departments of Anesthesiology, University of Louisville, Louisville, Kentucky, USASearch for more papers by this authorK. Tsueda, K. Tsueda Departments of Anesthesiology, University of Louisville, Louisville, Kentucky, USASearch for more papers by this authorTJ. Strickland, TJ. Strickland Departments of Computers & Information Science, University of Louisville, Louisville, Kentucky, USASearch for more papers by this author HL. Edmonds Ph.D., Corresponding Author HL. Edmonds Ph.D. Departments of Anesthesiology, University of Louisville, Louisville, Kentucky, USAProfessor & Director of Research Department of Anesthesiology School of Medicine University of Louisville Louisville, Kentucky 40292 U.S.A.Search for more papers by this authorA. Yli–Hankala, A. Yli–Hankala Departments of Anesthesiology, University of Louisville, Louisville, Kentucky, USASearch for more papers by this authorMR Heine, MR Heine Departments of Anesthesiology, University of Louisville, Louisville, Kentucky, USASearch for more papers by this authorK. Tsueda, K. Tsueda Departments of Anesthesiology, University of Louisville, Louisville, Kentucky, USASearch for more papers by this authorTJ. Strickland, TJ. Strickland Departments of Computers & Information Science, University of Louisville, Louisville, Kentucky, USASearch for more papers by this author First published: December 1993 https://doi.org/10.1111/j.1399-6576.1993.tb03646.xCitations: 7AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. REFERENCES 1 Russell IF. Conscious awareness during general anesthesia: relevance of autonomic signs and isolated arm movements as guides to depth of anesthesia. In: JG Jones ed., Bailliere' s Clinical Anesthesiology: Depth of Anesthesia London: WB Saunders, 1989: 511–532. Google Scholar 2 Ghoneim MM, Block RI. Learning and consciousness during general anesthesia. Anesthesiology 1992; 76: 279–305. 10.1097/00000542-199202000-00018 PubMedWeb of Science®Google Scholar 3 Hug CC Jr. Anesthesia monitoring. In: RD. Miller ed. Anesthesia 2nd ed., New York: Churchill–Livingstone, 1986: 411–463. Google Scholar 4 Edmonds HL Jr. Facial muscles: a window to unconsciousness. Ann Med 1992: 24(2): 77–78. 10.3109/07853899209148329 PubMedWeb of Science®Google Scholar 5 Paloheimo M., Wilson RC, Edmonds HL Jr. Comparison of neuromuscular blockade in upper facial and hypothenar muscles. J Clin Monitoring 1988; 4: 256–260. 10.1007/BF01617322 PubMedWeb of Science®Google Scholar 6 Stoeckel H., Schwilden H. Median EEG frequency. In: M. Rosen, JN. Lunn eds. Consciousness, Awareness and Pain in General Anesthesia. London: Butterworths, 1987: 53–60. Web of Science®Google Scholar 7 Heneghan CPH, Thornton C., Navaratnarajah M., Jones JG. Effect of isoflurane on the auditory evoked response in man. Br J Anesth 1987; 59: 277–282. 10.1093/bja/59.3.277 CASPubMedWeb of Science®Google Scholar 8 Plourde G., Picton TW. Human auditory steady–state response during general anesthesia. Anesth Analg 1990; 71: 460–468. 10.1213/00000539-199011000-00002 PubMedWeb of Science®Google Scholar Citing Literature Volume37, Issues100December 1993Pages 102-104 ReferencesRelatedInformation

This chapter explores that embolization, hypoperfusion, and hyperperfusion are all important sources of brain injury associated with surgery and endovascular procedures. Recent advances in ultrasound technology now permit diagnostic color-flow imaging of large intracranial vessels. However, practical considerations generally preclude the use of transcranial imaging for monitoring. As a result, continuous transcranial doppler (TCD) monitoring primarily utilizes flow-velocity measurement rather than imaging. It discusses that TCD ultrasound is currently the only direct continuous measure of these pathophysiologic processes. The description of TCD monitoring examines both the positive attributes and the limitations of this still-evolving technology. The information is clinically valuable and, in some cases, potentially lifesaving. Despite these attributes and a two-decade experience, this promising ultrasound technology remains substantially underutilized. As with transesophageal echocardiographic (TEE), those individuals willing to acquire the requisite TCD skills and adapt to its technical limitations can expect to reap the rewards of improved patient care.

This chapter reviews the use of transcranial magnetic stimulation (TCMS) for monitoring the functional integrity of the descending motor systems during surgery. It also discusses a potential role in the preoperative and postoperative period in conscious patients. It reviews that intraoperative use of somatosensory evoked potentials (SEPs) for monitoring the central nervous system function has been a popular technique. The chapter discusses that the appearance of several case reports describing new postoperative motor deficits with unchanged intraoperative SEP responses served as the stimulus for finding a direct motor system monitor. It also explores that two stimulation approaches have been developed for selectively exciting descending motor pathways. They are transcranial electrical stimulation (TCES) and TCMS. Both excite corticospinal tract (CST) neurons of origin using a transcranial technique. The chapter also focuses on the anatomy, physiology, and anesthetic considerations important to the use of TCMS for monitoring the descending motor system function. After establishing this foundation, it reviews the clinical experience using TCMS for monitoring the functional integrity of the CST-anterior horn cell pathway during spinal cord surgery.

A 64‐year‐old white man was admitted to the hospital with a nonhealing abdominal eruption. He denied insect bites, recent travel, fever, or chills. One year prior to admission, he had been diagnosed with diffuse large B‐cell lymphoma (DLBCL) in the retroperitoneum, which initially responded to chemotherapy, including eight cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R‐CHOP). Six months later, he presented with renal failure and was found to have ureteral compression from a recurrent retroperitoneal mass. Biopsy of this mass again revealed DLBCL positive for CD20, CD10, and CD79a and negative for CD3, CD5, and Cam5.2 by immunohistochemistry. Chemotherapy with R‐CHOP was resumed, and his renal function normalized. Two months later, he presented with an erythematous plaque on his abdomen. Admission hospital laboratory tests are shown in Table 1. On physical examination, he was afebrile, with a blood pressure of 100/68 mmHg and pulse of 105/min. Bilateral axillary lymphadenopathy was present, without splenomegaly or hepatomegaly. On skin examination, there was a dusky, erythematous, indurated plaque with sharp demarcations. Significant nonpitting edema was present (Fig. 1). Computed tomography (CT) scan and ultrasound of the abdomen and pelvis were negative for abscess. An infectious disease consultation was obtained, and treatment for cellulitis with vancomycin 1 g every 12 h, cefepime 2 g every 12 h, and metronidazole 500 mg every 6 h was initiated. Blood cultures remained negative throughout the hospital course; however, there was no improvement in the skin lesion. Subsequently, a dermatology consultation was obtained. Dermatology's initial diagnosis was that of lymphoma mimicking carcinoma erysipeloides. A punch biopsy was consistent with DLBCL with tumor cells similar in morphology to those seen in the biopsy of the retroperitoneal mass (Fig. 2). The immunohistochemistry results were also similar to those seen in the biopsy of the retroperitoneal mass, with the exception that CD20 staining was absent, consistent with continued rituximab treatment (Fig. 3). The diagnosis of lymphoma mimicking carcinoma erysipeloides was confirmed, antibiotics were discontinued, and, following the patient's wishes, he was discharged home with comfort care only. He died the next day. Laboratory tests at hospital admission with normal range in parentheses Aspartate aminotransferase (U/L) 69 (10–45) Alanine aminotransferase (U/L) 36 (20–65) Alkaline phosphatase (U/L) 177 (50–150) Lactate dehydrogenase (U/L) 1038 (90–240) Total protein (g/dL) 5.5 (6.7–8.7) Albumin (g/dL) 2.7 (3.5–4.8) Total bilirubin (mg/dL) 0.3 (0.1–1.3) Blood urea nitrogen (mg/dL) 24 (7–23) Creatinine (mg/dL) 1.2 (0.8–1.8) White blood cell count (/mm3) 2200 (4000–10,000) Erythematous, indurated plaque on the abdomen and pelvis with red to violaceous, 2–3‐mm‐diameter satellite papulesimageSkin biopsy showing dermis diffusely involved by a lymphomatous infiltrate (hematoxylin and eosin stain)imageImmunohistochemistry showing dermis with staining present for CD79aimage

Purpose The purpose of this study is to describe a case of carcinoma erysipelatoides occurring in association with diffuse large B-cell lymphoma (DLBCL). Material and Methods Case study including medical history, physical examination, laboratory and radiographic reports of a 64-year-old Caucasian male with a history of a nonhealing, erythematous, indurate plaque-like rash (20 × 32.5 cm) over his abdomen. Results Laboratory studies were significant for leukopenia (WBC 2.2/mm3), with a negative CT and ultrasonography of the abdomen and pelvis for any abcess. Initially, the patient was diagnosed with cellulitis and treated with antibiotics; however, blood cultures remained negative, and there was no improvement in the skin lesion. Subsequent punch biopsy was consistent with tumor cells similar in morphology and immunochemical staining to the original DLBCL. Antibiotics were discontinued; the patient was discharged home and expired shortly thereafter. Conclusion Although cases of carcinoma erysipelatoides occurring in association with solid tumors have rarely been described, to our knowledge, this is the first report of carcinoma erysipelatoides occurring in association with a hematologic malignancy. The treating physician needs to consider carcinoma erysipelatoides in the differential diagnosis of nonhealing rashes that resemble cellulitis in patients with lymphoma.