Fig. 8. Respiratory rate during the first hour after control (0 μg · kg−1· h−1) and infusions of 2, 4, and 6 μg · kg−1· h−1dexmedetomidine (corresponding to 0.33, 0.66, and 1.0 μg/kg) for 10 min. In each frame, mean respiratory response is represented by the heavy line and individual responses are represented by the light lines . Respiratory rates did not change significantly throughout the period of observation. bpm = breaths/min.