Regional cerebral saturation versus transcranial Doppler during carotid endarterectomy under regional anaesthesia

Background and objective The aim of this study was to compare a cerebral oximeter with transcranial Doppler (TCD) as a neurological monitor in patients undergoing carotid endarterectomy under regional anaesthesia. Methods Forty patients were enrolled for this prospective study. We recorded every adverse neurological event after arterial clamping and variations in parameters evaluated by the two monitoring systems in order to determine whether there was any correlation between TCD data and those obtained by regional cerebral saturation, the timing of detection of the adverse event in both clinical examination and instrumental data and the presence of any false positives or negatives in any of the two monitoring systems. Results Shunting was necessary in eight patients, following clinical signs of a neurological deficit during clamping. In these patients, a significant reduction in TCD values and regional cerebral saturation values from baseline was recorded. We observed a drastic reduction in TCD values in four patients during clamping (6 +/- 5 versus 41 +/- 4 cm s(-1)) that was not associated with any neurological deficit or reduction in regional cerebral saturation values (51 +/- 4 versus 54 +/- 7%). Instrumental detection of a neurological deficit anticipated the clinical observation of about 5-10 s. Conclusion We observed a greater reliability with the cerebral oximeter than with TCD in our patients. Eur J Anaesthesiol 26:643-647 (C) 2009 European Society of Anaesthesiology.