Pressors Flashcards
What is the mechanism of action of norepinephrine?
Alpha-1 agonist (vasoconstriction) and beta-1 agonist (increased HR and contractility).
When is vasopressin typically added in shock management?
When MAP is not achieved with norepinephrine alone, often after 0.1–0.2 mcg/kg/min.
Why is dopamine less favored in shock management?
It has a higher risk of arrhythmias and inconsistent efficacy compared to norepinephrine.
How does phenylephrine affect hemodynamics?
Pure alpha-1 agonist → vasoconstriction ↑ SVR, may cause reflex bradycardia.
What is the unique advantage of epinephrine in septic shock?
Provides both vasoconstriction and inotropy; useful when cardiac output is low.
What receptor does vasopressin act on to increase blood pressure?
V1 receptors on vascular smooth muscle, causing vasoconstriction.
What is the risk of prolonged high-dose vasopressors?
Tissue and organ ischemia due to excessive vasoconstriction.
