Fig. 1. Experimental protocol. The study consisted of the following phases: (1) arrival at the environmentally controlled experimental room and application of monitors; (2) adequate period of rest (approximately 30 min); (3) administration of drug or normal saline; (4) loading dose for 10 min; (5) maintenance dose for 60 min; (6) measurement of blood pressure variability (BPV) and cerebral blood flow velocity variability (CBFV) data; and (7) measurement of thigh cuff data.  Gray boxes = measurement of BPV and CBFV data;  open boxes = measurement of thigh cuff data. DEX = dexmedetomidine.