HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Ivan M. Rebeyka John G. Coles Himansu K. Dasmahapatra Sergio Kielmanowicz John Ikonomidis Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wilson, G. J. Articles by Taylor, M. Search for Related Content PubMed PubMed Citation Articles by Wilson, G. J. Articles by Taylor, M.

Ann Thorac Surg 1988;45:206-209
© 1988 The Society of Thoracic Surgeons

---

Articles

Loss of the Somatosensory Evoked Response as an Indicator of Reversible Cerebral Ischemia during Hypothermic, Low-flow Cardiopulmonary Bypass

From the Divisions of Cardiovascular Surgery, Neurology, and the Department of Pathology, Hospital for Sick Children, and the Department of Surgery, University of Toronto, Toronto, Ont, Canada

Accepted for publication October 15, 1987.

^* Address reprint requests to Dr. Wilson, Department of Pathology, Hospital for Sick Children, 555 University Ave, Toronto, Ont, Canada M5G 1x8

We assessed somatosensory evoked response (SSER) as a monitor of cerebral protection during nonpulsatile, hypothermic cardiopulmonary bypass (CPB). In 13 dogs under CPB, extracorporeal flow rate (EFR) thresholds for loss of SSER were determined by stepwise reduction of the EFR from 2.0 to 0.25 L/min/m² at perfusion temperatures of 35°C, 30°C, 25°C, and 20°C. Testing began at 35°C in Group 1 (N = 6) and at 20°C in Group 2 (N = 7). Immediately on loss of SSER (denoted as a decrease of 80% or more in the amplitude of the somatosensory evoked potentials), EFR was restored to 2.0 L/min/m.

Thresholds for loss of SSER ranged between 0.75 and 0.25 L/min/m². SSER was always restored on return of EFR to 2.0 L/min/m²; thus loss of SSER was a reversible ischemic change. Both groups had similar threshold values at 35°C, but at lower temperatures, Group 1 thresholds were significantly higher than those in Group 2. Since 35°C was the first test temperature for Group 1 but the last for Group 2, EFR reduction at 35°C apparently caused neurophysiological changes (depletion of cortical energy reserves), which diminished subsequent tolerance to ischemia, but EFR reduction at 20°C did not. Our findings show that loss of SSER warns of reversible cerebral ischemia, and support SSER monitoring as a useful measure of cerebral function during low-flow, hypothermic CPB.

This article has been cited by other articles:

				C. Limperopoulos, A. Majnemer, B. Rosenblatt, M. Shevell, C. Rohlicek, and C. Tchervenkov Multixnodality Evoked Potential Findings in Infants With Congenital Heart Defects J Child Neurol, November 1, 1999; 14(11): 702 - 707. [Abstract] [PDF]

				T. Sakurada, T. Kazui, H. Tanaka, and S. Komatsu Comparative Experimental Study of Cerebral Protection During Aortic Arch Reconstruction Ann. Thorac. Surg., May 1, 1996; 61(5): 1348 - 1354. [Abstract] [Full Text]

				H. Tanaka, T. Kazui, H. Sato, N. Inoue, O. Yamada, and S. Komatsu Experimental study on the optimum flow rate and pressure for selective cerebral perfusion Ann. Thorac. Surg., March 1, 1995; 59(3): 651 - 657. [Abstract] [PDF]

				P. C. Ferry Neurologic Sequelae of Open-Heart Surgery in Children: An 'Irritating Question' Arch Pediatr Adolesc Med, March 1, 1990; 144(3): 369 - 373. [Abstract] [PDF]