To date, intranasal dexmedetomidine pharmacokinetics have not been studied before on anesthetized adult patients in supine position. As use of intranasal dexmedetomidine is growing, it is crucial to enhance knowledge of its pharmacokinetics.~Open, exploratory study design will be used. Study population will consist of patients coming to elective unilateral hip or knee arthroplasty under general anesthesia in Turku University Hospital, Salo unit. Thirty patients compatible with the inclusion and exclusion criteria will be entered into the study after receiving informed consent. Plasma concentrations of dexmedetomidine and other significant data will be collected prospectively.~Intranasal dexmedetomidine 100 ug will be administered shortly after induction of general anesthesia using a mucosal atomization (LMA MAD Nasal™) device, according to normal local protocol. Second cannula will be placed after patient is anesthetized, in order to obtain blood samples. Venous blood samples will be obtained immediately prior to administration of dexmedetomidine (baseline) and thereafter at 5, 15, 45 min and 1, 4 h into EDTA tubes for determination of dexmedetomidine, and possibly adrenaline and noradrenaline plasma concentrations.~Vital signs (heart rate, blood pressure and peripheral oxygen saturation) will be followed during the operation, as well as in the post anesthesia care unit according to the local protocol. Before patients will be admitted to the ward, they are expected to be appropriately arousable and have vital signs in normal limits.
Aim of this study is to characterize the pharmacokinetics of dexmedetomidine in supine, anesthetized adult patients after intranasal dosing.