الفهرس 
CONSCIOUS SEDATIONOnly 14 pages are availabe for public view
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Abstract
Conscious sedation is a technique of providing analgesia, sedation and anxiolysis while ensuring rapid recovery without side effects. Conscious sedation is administered with the dual goals of rapidly and safely establishing satisfactory procedural condition for the performance of therapeutic or diagnostic procedures while ensuring rapid, predictable recovery with minimal post-operative sequels.
Dexmedetomidine is a highly selective alpha-2 agonist that provides anxiolysis and cooperative sedation without respiratory depression. It inhibits the release of norepinephrine via actions on the alpha2A (α-2A) adrenoceptors located in the locus ceruleus and the spinal cord, resulting in sedation and analgesia via sympatholysis.
Although well described and successful for sedation for nonpainful procedures, dexmedetomidine has been largely unsuccessful in providing adequate analgesia when used alone for painful procedures. To overcome these shortcomings, several agents can be used in combination with dexmedetomidine for monitored anesthesia care (MAC) during invasive procedures.
The common adverse effects of dexmedetomidine are hypotension, hypertension, and bradycardia. Dexmedetomidine has a biphasic effect on blood pressure, causing a decrease in the mean arterial pressure at low plasma concentrations (<1.9 ng.ml−1) due to vasodilation from the activation of the α2A receptor, and an increase at higher plasma concentrations due to vasoconstriction from the activation of the peripheral α2B receptor.
Ketamine is NMDA Receptor blocker which has multiple effects throughout the central nervous system, inhibiting polysynaptic reflexes in the spinal cord as well as excitatory neurotransmitter effects in selected areas of the brain. In contrast to the depression of the reticular activating system induced by the barbiturates, ketamine functionally “dissociates” the thalamus (which relays sensory impulses from the reticular activating system to the cerebral cortex) from the limbic cortex (which is involved with the awareness of sensation).
The aim of this study was to study the effect of dexemdetomidine with fentanyl versus ketamine with fentanyl on hemodynamic stability and recovery during conscious sedation in dilatation and curettage procedure. The comparison included the vital data and recovery time. The effect of the drugs on hemodynamics and monitoring the occurrence of any complication were also done.
In our study, 50 patients were randomly divided into 2 equal groups. group DF received dexmedtomidine loading dose 1 μg/kg over 10 min and followed by 0.5 μg/kg/hr infusion till completion of surgery.
And group KF received ketamine 0.5 mg/kg slow intravenous Bolus.
Our study showed that dexmedetomidine is a safe drug with good hemodynamic and recovery time, also exerts sedative and analgesic effects without respiratory depression, unlike most analgesic/sedative drugs, such as ketamine, opioids, benzodiazepines, and propofol.