Fig. 3. Time course of the mean (with SEM error bars) blood drug concentrations in the superior sagittal sinus (solid circles) and aorta (open circles) from 3-min bilateral carotid arterial infusions of 48 μmol of levobupivacaine (top ), bupivacaine (center ), and ropivacaine (bottom ) is shown. The time courses of drug concentrations for the 24-, 72-, and 96-μmol doses (not shown) were similar.