Pulmonary Vasodilators Flashcards
What are the four pulmonary vasodilators?
Nitrous oxide, Eproprostenol (Caripul), Alprostadil, and Sildenafil
Which pulmonary vasodilators are inhaled?
Nitrous oxide and Epoprostenol.
Which pulmonary vasodilator is given IV?
Alprostadil
Which pulmonary vasodilator is given orally?
Sildenafil
What are the two main reasons we want to vasodilate in the lungs?
To decrease resistance against the right side of the heart and to redistribute pulmonary blood flow through the lungs (by expanding vessels to control where it goes)
What are the effects of endogenous NO on the body?
Regulates vascular tone and inhibits platelet aggregation.
What is the half life on NO in the bloodstream?
0.1-5 seconds
Why is the short half life of NO an advantage?
Vasodilation will occur locally but the NO will be inactivated before it reaches systemic circulation.
What inactivates NO?
NO binds with hemoglobin, inactivating it.
Describe the negative effects of NO.
NO is unstable so it easily combines with oxygen to form NO2 (nitric acid). If Nitric acid is being delivered we may cause acid pneumonitis in pts.
How do we control NO delivery?
By measuring inspiratory flow and injecting a proportional amount of NO into the inspiratory limb of the vent. Concentration is measured prior to breath entering patient, ensuring exact delivery.
What device do we use for NO delivery.
The iNOmax machine.
What is the initiating dose of NO and the effective dose?
20ppm initiating, 1-2 ppm effective.
What are the two primary uses for NO?
To reverse or decrease pulmonary hypertension or right heart failure and to improve oxygenation due to hypoxic respiratory failure.
When administering NO over a long period of time, what happens to endogenous NO production?
Endogenous production is reduced or halted. Sudden discontinuation may result in rebound hypertension or hypoxemia, so it should be slowly weaned.
