J. Schön¹, V. Serien¹, H. Heinze¹, T. Hanke², M. Bechtel², S. Eleftheriadis⁴, H.-V. Groesdonk¹, L. Dübener³, M. Heringlake¹
Departments of ¹Anesthesiology and ²Cardiac and Thoracic Vascular Surgery, University of Lübeck, Lübeck, Germany; ³Department of Cardiovascular Surgery, Children’s National Medical Center, Washington, DC, USA; ⁴Department of Anesthesiology, General Univeresity Hospital of Alexandroupolis, Greece
[Applied Cardiopulmonary Pathophysiology 13: 201-207, 2009]

Abstract

Objective: To determine the relationship between a decrease in cerebral oxygen saturation (rSO2) – determined by near-infrared spectroscopy – below 80% of preoperative baseline and the incidence of stroke in patients undergoing deep hypothermic circulatory arrest (DHCA) for cardiac and/or thoracic aortic surgery.
Setting: Cardiac anesthesia unit of a University Hospital 
Design: Retrospective analysis of the anesthesia charts and the institutional cardiac surgery database for the year 2006.
Patients: 51 patients undergoing DHCA monitored bi-hemispherically with an INVOS 5100 cerebral oxymeter.
Interventions: None
Measurements and main results: Patients were grouped according to an rSO2 less or greater than 80% of baseline for the left or right hemisphere in a desaturation (n = 11) and a no-desaturation group (n = 40). No between group differences in demographic variables and preoperative baseline rSO2 were observed. Duration of cardiopulmonary bypass, aortic cross-clamp, DHCA and effective cerebral ischemia were not different between the groups. The minimal absolute and relative rSO2-levels in the desaturation group were significantly lower than in the no-desaturation group. Two patients in the desaturation group but none in the no-desaturation group presented with a postoperative stroke (18.1% vs. 0%; p = 0.043).
Conclusion: These findings suggest that an rSO2 lower than 80% of preoperative baseline in patients undergoing cardiac and/or thoracic aortic surgery with DHCA is associated with a significant risk of an adverse neurological outcome. Preventing cerebral desaturation during DHCA procedures may thus help to reduce postoperative neurological deficits.

Keywords: near-infrared spectroscopy, cerebral oxygenation monitoring, thoracic vascular surgery, cardiac surgery


Address for corresponding:
Matthias Heringlake, M.D., Ph.D., Klinik für Anästhesiologie, Universität zu Lübeck, Ratzeburger Allee 160, 23538 Lübeck; Germany
heringlake@bitte-keinen-spamt-online.de