Dexmedetomidine

Question 1

Dexmedetomidine Mechanism of Action

Answer 1

Nonselective alpha 2 agonist. Sedation receptors in locus cereleus, analgesic receptors in locus cereleus & spinal cord – produces decreased activity of LC & VLPO, increases GABA & galanin release in TMN (decreases histamine in cortical & subcortical areas), inhibits ion conductance through voltage gated calcium activated potassium channels

Question 2

Dexmedetomidine CV Effects

Answer 2

Decreased: HR, SVR, & indirectly CO, SBP & Contractility

Question 3

Dexmedetomidine Pulmonary Effects

Answer 3

Decreased minute ventilation but maintains CO2 response, similar to natural sleep

Question 4

Dexmedetomidine CNS Effects

Answer 4

Possibly some neuroprotection

Question 5

Dexmedetomidine Anesthetic uses, premedication & dose

Answer 5

0.33 - 0.67 mcg/kg 15 minutes before surgery IV - decreases induction agent dose & decreases MAC

Question 6

Dexmedetomidine MAC uses & dose

Answer 6

1 mcg/kg over 10 minutes, 0.7 mcg/kg/min to keep BIS 70-80, slower onset/offset than propofol

Question 7

Dexmedetomidine Maintenance of general anesthetic (no dose)

Answer 7

Reduces MAC of inhaled agent, reduces postoperative opioid requirements, not useful solo