[Dexmedetomidine/propofol association for plastic surgery sedation during local anesthesia.]. / Dexmedetomidina associada a propofol em sedação durante anestesia local para cirurgia plástica.

BACKGROUND AND OBJECTIVES: Dexmedetomidine is a new alpha2-adrenergic receptor agonist with potentially useful characteristics for anesthesia. This comparative study aimed at evaluating the effects of dexmedetomidine on propofol requirements and cardiovascular/respiratory stability during plastic surgery sedation under local anesthesia. METHODS: Participated in this study 40 female patients aged 16 to 60 years, physical status ASA I or II, scheduled for elective face, nose and breast plastic surgeries under local anesthesia. Patients were randomly allocated into two groups of twenty patients: C (control) and D (dexmedetomidine). Sedation was achieved in both groups with 1 mg.kg-1 bolus propofol followed by continuous infusion at an adjusted rate to provide conscious sedation. Group D patients received continuous intravenous dexmedetomidine at a rate of 0.01 microg.kg-1.min-1, concomitant with propofol infusion. The following were evaluated: effect of dexmedetomidine on propofol requirements; cardiovascular (SBP, DBP, MBP, HR) and respiratory (SpO2, P ET CO2) parameters; quality of perioperative bleeding control and postanesthetic recovery features. RESULTS: Mean propofol infusion rate was lower in group D (35.2 +/- 5.3 microg.kg-1.min-1) as compared to group C (72.6 +/- 8.5 microg.kg-1.min-1). Mean SBP, DBP, MBP values have decreased as from 30 min in group D, remaining stable until procedure completion, while in Group C they have increased. HR remained stable in group D where as increased as from 30 min in group C. Mean time to open eyes under command was lower in group D (6.3 +/- 2.5 min) as compared to group C (8.9 +/- 2.7 min). Perioperative bleeding control was better in group D as compared to group C. CONCLUSIONS: Dexmedetomidine/propofol association for sedation is safe and has the following advantages: decrease in propofol requirements, cardiovascular stability, good perioperative bleeding control, lack of significant effects on ventilation.