Fig. 8. Dose–effect relationships for cardiovascular effects of bupivacaine, levobupivacaine, and ropivacaine infused bilaterally over 3 min into the carotid arteries of sheep. Panels from top: mean arterial blood pressure, heart rate, cardiac output, stroke volume, and left ventricular dP/dt^max.as an index of myocardial contractility. (Left ) Maximum measured values; (right ) values for SED¹⁰. Mean values (with SEM error bars) are shown. Statistical inference is shown in table 2.