Propofol/Remifentanil Anesthesia Might Not Alter the Middle Cerebral Artery Diameter by Digital Subtraction Angiography

Introduction Transcranial Doppler (TCD) of the middle cerebral artery (MCA) enables the measurement of the mean blood velocity (MCA(Vm)) and the estimation of the cerebral blood flow (CBF), provided that no significant changes occur in the MCA diameter (MCA(Diam)). Previous studies described a decrease in the MCA(Vm) associated with the induction of total intravenous anesthesia (TIVA) by propofol and remifentanil. This decrease in blood velocity might be interpreted as a decrease in the CBF only where the MCA(Diam) is not modified across TCD examinations. Methods In this observational study, we measured the MCA(Diam) of 24 subjects (almost exclusively females) on digital subtraction angiography under awake and TIVA conditions. Results Across the two phases, we observed a decrease in the mean arterial blood pressure (from 84 +/- 9 to 71 +/- 6 mmHg; p < 0.001) and heart rate (76 +/- 10 vs. 65 +/- 8 beats/min; p < 0.001), and a concomitant decrease in the MCA(Vm) (61 vs. 42 cm/s; p < 0.001). In contrast, the MCA(Diam) did not vary in association with TIVA (2.3 +/- 0.2 vs. 2.3 +/- 0.2 mm; p = 0.52). Conclusions Those results suggested that in this population, no significant changes in the MCA(Diam) are associated with TIVA.