Dexmedetomidine Flashcards
Effects
Sedation Anxiolysis Hypnosis Analgesia Sympatholysis
Classification
A2 adrenergic agonist
Mechanism of action
No selective a2agonist
A2 adrenoreceptoes are membrane spanning G proteins
- Inhibition of adenylate cyclase
- Modulation of ion channel
- a2B and a2C receptors in the brain and spinal chord
- stimulation leads to sympatholysis, sedation, and antinociception
Sedation
Receptors in the locus cerelerus
Analgesia
Receptors in a2 in the LC and spinal cord
LC and ventrolateral preop tic nucleus (VLPO) activity
- Increase GABAergic and galanin release in the turbo mammillary nucleus (TMN) which results in a decrease in histamine release in cortical and subcortisol areas
- Inhibit ion conductance through voltage gated calcium activate potassium channel
Cardiovascular effects
Decease HR, SVR
Indirectly decrease CO, SBP, contractility
Pulmonary effects
Decrease minute ventilation but maintains CO2 response
Similar to natural sleep
CNS effects
Not well defined
Neuro protection
Anesthesic use
Premedication: 0.33 to 0.67 mcg/kg 15 mins before surgery
Induction dose effect
Decreases
MAC
Decreases MAC
1mcg/kg over 10 mins
Slower onset and offset than propofol
Similar cardio respiratory effects
BIS
0.7 mcg/kg keeps bis at 70-80
Maintenance
Reduces MAC inhaled agent
Reduces postoperative opioid requirements
