Fig. 4. Dose–effect relations for time integral of changes in left ventricular dP/dtmax, stroke volume, left coronary artery blood flow, and heart rate from site-directed left main coronary arterial infusions of rac -, R -, and S -thiopental and propofol to conscious adult sheep. Mean values for SED5( open symbols ) and SED15( closed symbols ) along with their 95% confidence intervals are shown. SED = sum of effect differences.