Fig. 4. The maximum measured mean (with SEM error bars) drug blood concentrations (Cmax) in the sagittal sinus blood (top ) and aorta (bottom ) for 24-, 48-, 72-, and 96-μmol doses of bupivacaine, levobupivacaine, and ropivacaine infused bilaterally over 3 min into the carotid arteries.