Anticholinergic Premedication for Sedation With Dexmedetomidine During Spinal Anesthesia

"To evaluate the effectiveness of atropine on prevention bradycardia,atropine 0.01\~0.03mg/kg up to 0.5mg would be injected intravenously just before starting loading dose of dexmedetomidine in group A.~During operation, heart rate decreasing 30% from initial heart rate or under 40/min would be regarded as bradycardia needing treatment, and atropine 0.5mg will be injected intravenously. This intervention would be applied to both group."

Dexmedetomidine is a highly selective a2 adrenergic receptor antagonist used as sedative agent. After confirming the fixation level of spinal anesthesia, the loading dose(0.6ug/kg) of dexmedetomidine which is diluted with normal saline as 4ug/mL would be started for 10 minutes.Maintenance dose(0.25ug/kg/hr) would be continued after loading dose.

Systolic blood pressure decreasing 30% from basal blood pressure or under 90 mm Hg would be regarded as hypotension needing treatment, and ephedrine 5mg will be injected intravenously.