JOURNAL HOME CME HOME THIS MONTH PAST ISSUES ETOC COLLECTIONS AUTHORS REVIEWERS EDITORIAL BOARD FEEDBACK RSS HELP
		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by Welsby, I. J. Articles by Borel, C. O. Search for Related Content PubMed PubMed Citation Articles by Welsby, I. J. Articles by Borel, C. O. Related Collections Monitoring (Cardiac) Monitoring (Non-cardiac)

---

TECHNOLOGY, COMPUTING, AND SIMULATION

The Bispectral Index in the Diagnosis of Perioperative Stroke: A Case Report and Discussion

Ian J. Welsby, FRCA^*, J. Mark Ryan, FRCR^,, John V. Booth, FRCA^*, Ellen Flanagan, MD^*, Robert H. Messier, MD^,, and Cecil O. Borel, MD^*

Departments of *Anesthesiology, Radiology, and Surgery, Duke University Medical Center, Durham, North Carolina

Address correspondence and reprint requests to Ian J. Welsby, FRCA, Box 3094, Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710. Address e-mail to welsb001{at}mc.duke.edu

	Abstract

Top Abstract Introduction Case Report Discussion References

 

IMPLICATIONS: We describe a case where the frequently used bispectral index (BIS) monitor provided the first indication of a massive stroke. The diagnosis of stroke should be considered in the event of an unexplained, sudden, and sustained decrease in the BIS.

	Introduction

Top Abstract Introduction Case Report Discussion References

 
We discuss a case where the bispectral index (BIS; Aspect Medical, Natick, MA) was the earliest indicator of acute perioperative stroke during the removal of an Abiomed BVS 5000^® (Penn State Cardiovascular Center, Hershey, PA) left ventricular assist device (LVAD). Up to 3% of cardiac surgical patients suffer serious, typically embolic, neurological complications, with an associated 20% mortality rate (1). The opportunity to make an earlier diagnosis may help improve outcome in this group as novel therapeutic options become available.

	Case Report

Top Abstract Introduction Case Report Discussion References

 
A 69-yr-old man underwent emergency coronary artery bypass grafting after acute myocardial infarction complicated by postinfarction angina and cardiogenic shock. Large-dose right ventricular inotropic support and an Abiomed BVS 5000^® LVAD were required to help separation from cardiopulmonary bypass.

Six days later, ventricular function had recovered sufficiently to attempt LVAD removal. The patient had been heparinized during this time to reduce the substantial risk of thrombus formation within the device. Abnormal laboratory results included a platelet count of 86 x 10⁹/L, prothrombin time of 16.9 s, activated partial thromboplastin time of 63.2 s, serum urea nitrogen of 113 mg/dL, and creatinine of 2.9 mg/dL.

Separation from cardiopulmonary bypass was successful on the first attempt with moderate inotropic support, but the BIS index precipitously decreased from its previously steady state of 50–60 to <10 and remained <15 until the end of the case. Despite heparinization, a cerebral embolus was suspected, and a computerized tomography of the brain was performed the next day, confirming extensive cerebral infarction (Fig. 1, A and B). The patient was managed conservatively and quickly succumbed to complications consistent with intracranial hypertension.

View larger version (105K): [in this window] [in a new window]   Figure 1. (A) Computed tomography demonstrates extensive areas of hypodensity in the right parietal and temporal lobes consistent with acute infarct in the territory of the right middle cerebral artery (arrows). (B) There is also hypodensity in the left parietal occipital region with extension into the thalamic area consistent with acute left posterior cerebral artery infarction (arrows).

	Discussion

Top Abstract Introduction Case Report Discussion References

If cerebral embolization is suspected, then early diagnosis is both essential and feasible. Computerized tomography scanning, within the first five hours after the onset of symptoms, can demonstrate changes in 70%–80% of patients presenting with acute hemispheric stroke (9) and is essential to exclude cerebral hemorrhage. Definitive therapy involves reperfusion of ischemic brain tissue. Intraarterial thrombolysis within six hours of the cerebral event is the most effective method (10), and its use has been reported in the successful treatment of cerebral embolism associated with LVAD support (11). Successful intraarterial suction thrombectomy has also been described for internal carotid, but not more distal, thrombi (12), and a laser system is being developed (EndoVasix, Belmont, CA). Mechanical thrombolysis has the attraction of avoiding the bleeding complications associated with thrombolytic drugs.

Supportive measures aim to avoid exacerbating brain injury by controlling the rate of rewarming (13), aggressively controlling fever (14), and treating increased intracranial pressure. In addition to hyperventilation, osmotherapy, and barbiturate therapy, moderate hypothermia (32°C–33°C) is effective in reducing intracranial pressure (15).

In summary, this case report demonstrates that a change in intraoperative BIS index may be the first indication of a serious cerebral event. A sudden and sustained change in the BIS index may merit further investigation because large vessel thrombosis may be amenable to treatment. For postoperative cases, suction thrombectomy will obviously become the preferred intervention for carotid occlusion and for more distal lesions as this and other techniques develop. In the immediate postoperative period, thrombolytics are typically contraindicated. However, if an extensive infarction is developing, particularly including the dominant hemisphere, the benefits of attempted reperfusion may outweigh the risk of mediastinal hemorrhage. For example, the mortality associated with infarction of more than 50% of the middle cerebral artery territory is 85% (9), and although autologous retransfusion of mediastinal blood and reoperation would likely be required to control bleeding, thrombolysis may reduce the overall mortality. Should reperfusion therapy be judged as too risky, aggressive monitoring and treatment of intracranial hypertension, including sustained hypothermia, may improve outcome.

Accurate definition of the value of the frequently used BIS index as an early warning of perioperative stroke is important to prepare us for the rapidly developing therapeutic options for this devastating complication.

	References

Top Abstract Introduction Case Report Discussion References

 

1. Roach GW, Kanchuger M, Mangano CM, et al. Adverse cerebral outcomes after coronary bypass surgery: Multicenter Study of Perioperative Ischemia Research Group and the Ischemia Research and Education Foundation Investigators. N Engl J Med 1996; 335: 1857–63.[Abstract/Free Full Text]
2. Rosow C, Manberg PJ. Bispectral index monitoring. Anesthesiology Clinics of North America 2001; 19: 947–66.[Medline]
3. Cho I, Smullens SN, Streletz LJ, Fariello RG. The value of intraoperative EEG monitoring during carotid endarterectomy. Ann of Neurology 1986; 20: 508–12.[ISI][Medline]
4. Blume WT, Ferguson GG, McNeill DK. Significance of EEG changes at carotid endarterectomy. Stroke 1986; 17: 891–7.[Abstract/Free Full Text]
5. Cillessen JP, van Huffelen AC, Kappelle LJ, et al. Electroencephalography improves the prediction of functional outcome in the acute stage of cerebral ischemia. Stroke 1994; 25: 1968–72.[Abstract]
6. Merat S, Levecque JP, Le Gulluche Y, et al. BIS monitoring may allow the detection of severe cerebral ischemia. Can J Anaesth 2001; 48: 1066–9.[Abstract/Free Full Text]
7. Kluger MT. The bispectral index during an anaphylactic circulatory arrest. Anaesth Intensive Care 2001; 29: 544–7.[ISI][Medline]
8. Engl MR. The changes in bispectral index during a hypovolemic cardiac arrest. Anesthesiology 1999; 91: 1947–9.[ISI][Medline]
9. von Kummer R, Meyding-Lamade U, Forsting M, et al. Sensitivity and prognostic value of early CT in occlusion of the middle cerebral artery trunk. AJNR Am J of Neuroradiology 1994;15:9–15; discussion 16–8.
10. Schellinger PD, Fiebach JB, Mohr A, et al. Thrombolytic therapy for ischemic stroke: a review. II. Intra-arterial thrombolysis, vertebrobasilar stroke, phase IV trials, and stroke imaging. Crit Care Med 2001; 29: 1819–25.[ISI][Medline]
11. Kasirajan V, Smedira NG, Perl J 2nd, McCarthy PM. Cerebral embolism associated with left ventricular assist device support and successful therapy with intraarterial urokinase. Ann of Thoracic Surgery 1999; 67: 1148–50.
12. Lutsep HL, Clark WM, Nesbit GM, et al. Intraarterial suction thrombectomy in acute stroke. AJNR 2002; 23: 783–6.[Abstract/Free Full Text]
13. Grigore AM, Grocott HP, Mathew JP, et al. The rewarming rate and increased peak temperature alter neurocognitive outcome after cardiac surgery. Anesth Analg 2002; 94: 4–10.[Abstract/Free Full Text]
14. Azzimondi G, Bassein L, Nonino F, et al. Fever in acute stroke worsens prognosis: a prospective study. Stroke 1995; 26: 2040–3.[Abstract/Free Full Text]
15. Schwab S, Georgiadis D, Berrouschot J, et al. Feasibility and safety of moderate hypothermia after massive hemispheric infarction. Stroke 2001; 32: 2033–5.[Abstract/Free Full Text]

This article has been cited by other articles:

				C. S. Leggat and G. W. Fischer Early Detection of an Acute Cerebral Event During Cardiopulmonary Bypass Using a Bispectral Index Monitor Seminars in Cardiothoracic and Vascular Anesthesia, March 1, 2008; 12(1): 80 - 82. [Abstract] [PDF]

				K. P. Unnikrishnan, P. K. Sinha, K. Sriganesh, and P. R. Suneel Case report: Alterations in bispectral index following absolute alcohol embolization in a patient with intracranial arteriovenous malformation: [Modification de l'index bispectral suite a une embolisation avec alcool absolu chez un patient souffrant de malformation arterioveineuse intracranienne] Can J Anesth, November 1, 2007; 54(11): 908 - 911. [Abstract] [Full Text] [PDF]

				A. Deogaonkar, R. Vivar, R. E. Bullock, K. Price, I. Chambers, and A. D. Mendelow Bispectral index monitoring may not reliably indicate cerebral ischaemia during awake carotid endarterectomy Br. J. Anaesth., June 1, 2005; 94(6): 800 - 804. [Abstract] [Full Text] [PDF]

				Y. Morimoto, Y. Monden, K. Ohtake, T. Sakabe, and S. Hagihira The Detection of Cerebral Hypoperfusion with Bispectral Index Monitoring During General Anesthesia Anesth. Analg., January 1, 2005; 100(1): 158 - 161. [Abstract] [Full Text] [PDF]

				N. Adam and P. S. Sebel BIS Monitoring: Awareness and Catastrophic Events Seminars in Cardiothoracic and Vascular Anesthesia, March 1, 2004; 8(1): 9 - 12. [Abstract] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by Welsby, I. J. Articles by Borel, C. O. Search for Related Content PubMed PubMed Citation Articles by Welsby, I. J. Articles by Borel, C. O. Related Collections Monitoring (Cardiac) Monitoring (Non-cardiac)

Anesthesia & Analgesia® is published for the International Anesthesia Research Society® by Lippincott Williams & Wilkins with the assistance of Stanford University Libraries' HighWire Press®. Copyright 2006 by the International Anesthesia Research Society. Online ISSN: 1526-7598   Print ISSN: 0003-2999