Inotropes, Vasopressors, and Vasodilators Flashcards
What condition is indicated by SBP < 90 mm Hg, CI < 2.2 L/min/m2, and PCWP > 12 mm Hg?
Cardiogenic shock
Cardiogenic shock is a state of inadequate blood flow to the body’s organs due to the heart’s inability to pump effectively.
According to the SOAP II trial, which medication showed decreased rates of death in patients with cardiogenic shock?
Norepinephrine
Patients randomized to receive norepinephrine had lower mortality compared to those receiving dopamine (p = 0.03).
What is the mechanism of action of milrinone?
Phosphodiesterase inhibitor that increases cAMP
Milrinone causes an increase in myocardial contractility and has a dose-dependent vasodilatory effect.
In patients with LV systolic dysfunction, which agent is most appropriate when exhibiting signs of shock?
Dopamine
Dopamine is preferred due to its inotropic and vasoconstrictive properties.
What is no reflow in the context of percutaneous interventions?
Failure of oxygen reperfusion to ischemic tissue
This condition can lead to cell injury, edema, and platelet plugs due to reactive oxygen species.
Which agents are used to treat vasospasm?
- Diltiazem
- Verapamil
- Sodium nitroprusside
- Nitroglycerin
These are preferred over acetylcholine, which is ineffective in patients with endothelial dysfunction.
What is the preferred vasodilator for acute vasodilatory challenges in pulmonary arterial hypertension?
Inhaled nitric oxide (NO)
It has a rapid onset and minimal systemic effects.
What is the usual starting dose range for norepinephrine?
2 mcg/min to 30 mcg/min
Norepinephrine is commonly used in septic shock and cardiogenic shock.
What is the treatment for severe anaphylactoid reactions secondary to contrast media?
Epinephrine in bolus doses of 10 mcg
Administer until MAP is >60 mm Hg; IV steroids should not be used alone in severe reactions.
True or False: Phenylephrine increases heart rate.
False
Phenylephrine is a pure alpha agonist with minimal beta-adrenergic effects.
What should be questioned before administering nitroglycerin to a patient with pulmonary arterial hypertension?
Use of phosphodiesterase inhibitors
These can interact with nitrates, leading to hypotension.
What is the initial treatment for hypotension associated with inferior wall and right ventricular infarction?
Generous IV volume administration
This is crucial before considering medications like nitroglycerin.
What does nitric oxide do to vascular smooth muscle?
Increases cGMP production, leading to relaxation
It also inhibits platelet aggregation and neutrophil adhesion.
What is the effect of labetalol in hypertensive crises?
Preferred treatment due to vasodilatory properties
It is particularly useful in patients with cardiac ischemia.
What is a major risk associated with sodium nitroprusside?
Cyanide toxicity
It is released during metabolism and can cause serious complications.
What is the role of methylergonovine in vascular health?
Acts as a serotonin receptor agonist
It can cause vasodilation in healthy endothelium but may lead to vasoconstriction in abnormal conditions.
How does dopamine’s effect vary with dosage?
Low doses affect dopamine receptors; higher doses stimulate alpha-1 receptors
This results in increased BP at higher doses.
What is the effect of low-dose dopamine (<5 mcg/kg/min)?
Primarily vasodilation via dopamine receptors
It was previously thought to protect renal function, but this is not supported by current data.
What is the renal protective effect of dopamine?
Dopamine may help resolve oliguria but does not improve other renal outcomes
Data do not support its prophylactic use in preventing kidney injury during catheterization procedures.
What factors affect tissue ischemia and sloughing during drug infiltration?
Alpha-1 vasoconstriction properties and local drug concentration
The rate of infusion does not affect tissue ischemia.
What should be done once extravasation is observed?
Infusion should be discontinued and slow aspiration of the drug should be performed
Cold or warm compresses may help with other medications, but catecholamines require immediate treatment with phentolamine.
What is phentolamine used for?
To block hypertensive effects of catecholamines and diagnose pheochromocytoma
Phentolamine is prepared by diluting 5 mg in 10 mL of normal saline and injecting subcutaneously.
Which inotropic agent is indicated for low cardiac output?
Dobutamine
It does not significantly impact afterload.
What is the effect of dopamine at low doses?
Strong beta agonist but can increase systemic vascular resistance (SVR)
This is not ideal for patients who are not in shock.
What is the primary action of nitroglycerin at low doses (<30 mcg/min)?
Venodilation
At doses above 30 mcg/min, it exhibits balanced venous and arterial dilation.
What effect does nitroglycerin have on coronary collateral flow compared to nitroprusside?
Increases coronary collateral flow
Nitroprusside decreases coronary collateral flow.
What should be prioritized for a patient not exhibiting adverse reactions to nitroglycerin?
Uptitration of nitroglycerin
Morphine should only be used for pain unrelieved by nitroglycerin.
True or False: Early IV metoprolol has been shown to reduce infarct size in patients experiencing STEMI.
False
Studies indicate it has not shown a reduction in infarct size.
What are antidotes for drug extravasations other than catecholamines?
Hyaluronidase and sodium thiosulfate
These compounds are used for other drug extravasations.
