Propofol: A highly lipophilic GABA agonist that may be used for long-term sedation. Disadvantages include vasodilation, which can result in hypotension and an increase in serum triglycerides and lipase.
Etomidate: A GABA agonist that has the advantage of being the most hemodynamically neutral. It does not cause changes in heart rate, blood pressure, or cardiac output. However, it inhibits cortisol synthesis, which can lead to (reversible) adrenocortical suppression. Because of this, it is often avoided in patients with septic shock, and it should not be used as maintenance of sedation after induction.
Ketamine
Mechanism of action
An N-methyl-D-aspartate (NMDA) antagonist that is similar to PCP
Effects
Dissociative anesthesia: unique anesthetic state with analgesia, intact spontaneous breathing, amnesia, and no complete loss of consciousness