Figure 3. Changes in heart rate (HR), mean arterial pressure (MAP), sympathetic efferent nerve activity (SENA), and vein diameter (VD) produced by bilateral carotid occlusion (BCO) before and four times after epidural or intramuscular injection of lidocaine (arrow and dotted line). Each pair of data points connected by a line represent the initial value immediately before BCO and the value during BCO. Baseline for SENA and VD are values just before injection. Values are means +/- SE. *Significant change. (section)Significant difference between changes in epidural and intramuscular groups.