Section Editor: Tony Gin A Double-Blind, Crossover Assessment of the Sedative

BACKGROUND: The alpha2-receptor agonist, dexmedetomidine, provides sedation with facilitated arousal and analgesia with no respiratory depression. These properties render it potentially useful for anesthesia premedication, although parenteral administration is not practical in this setting. We designed this study to evaluate the sedative, anxiolytic, analgesic, and hemodynamic effects of dexme-detomidine administered intranasally in healthy volunteers. METHODS: Koch’s design for crossover trials (three-treatment and two-period de-sign) was adopted. The study was double-blind and there were three treatment groups: A (placebo), B (intranasal dexmedetomidine 1 g/kg) and C (intranasal dexmedetomidine 1.5 g/kg). Each of the 18 subjects participated in two study periods. The study drug was administered intranasally after baseline observations of modified Observer Assessment of Alertness/Sedation Scale, visual analog scale of sedation, bispectral index, visual analog scale of anxiety, pain pressure threshold measured by an electronic algometer, systolic blood pressure (SBP) and diastolic blood pressure, heart rate, respiratory rate, and oxygen saturation. These wer