Impact of hypotension on cerebral perfusion during general anesthesia induction: A prospective observational study in adults

INTRODUCTION During anesthesia, decreases in mean arterial pressure (MAP) are common but the impact on possible cerebral hypoperfusion remains a matter of debate. We evaluated cerebral perfusion in patients with or without cardiovascular comorbidities (Hi-risk vs Lo-risk) during induction of general anesthesia and during hypotensive episodes. METHODS Patients scheduled for neuroradiology procedure using standardized target-controlled Propofol-Remifentanil infusion were prospectively included. Monitoring included Transcranial Doppler (TCD) measuring mean blood velocity of the middle cerebral artery (Vm), Bispectral Index with burst suppression ratio (SR) and cerebral Near-Infrared Spectroscopy (NIRS). Hypotensive episodes were treated with a 10 µg bolus of Norepinephrine. RESULTS Eighty-one patients were included, 37 Hi-risk and 44 Lo-risk. During induction of anesthesia, MAP and Vm decreased in all patients, with greater changes observed in Hi-risk patients compared to Lo-risk patients (-34 [38-29]% vs -17 [25-8]%, P