10e- Pulmonary Vasodilators Flashcards
(25 cards)
What is saddle pulmonary embolis?
A massive clot that blocks 100% of the blood flow to the lungs
What can this lead to?
- Dead space ventilation
- No O2 pick up or CO2 drop off
- RR ↑, HR + BP ↑
- Looking scared + sweating
Wbat can happen if pulmonary vascular resistance gets too high?
- Less blood leaves right side of heart
- Less blood to left side of heart enters
- Less systemic blood flow + ↓BP
What are the 3 categories of Pulmonary Vasodilatory Categories?
- Nitric Oxide (NO)
- Prostaglandins
- PDE-5 Inhibitors
Nitric Oxide (NO)
How does NO work?
- NO –><– Guanylyl Cyclase
- Complex –> ↑cGMP
- ↑cGMP –> ↓Ca2+
- ↓Ca2+ –> Vasodilation
Nitric Oxide (NO)
What drug falls under this category?
Inhaled Nitric Oxide (iNO)
iNO
What is its half life and mode of delivery?
- Half Life: Less than 5 sec
- Delivery: Inhaled and continuously delivered
iNO
What does it mean that it is a “selective vasodilator”?
- Only works on pulmonary vasculatore that is working with alveoli that are intubated.
- No ventilation to alveoli –> No action there
iNO
How does iNO help?
- Improves perfusion to ventilated areas.
- This helps decrease the shunt.
iNO
What does iNO help treat?
newborn + adults
- Persistent pulmonary hypertension + hypoxia of newborns
- Treat severe hypoxemia + pulmonary hypertension in adults
iNO
What are primary side effects with iNO?
- NO2 formation
- Methemoglobin creation
- Rebound Hypoxemia
iNO
Why is the second one right?
B/c the greater the FiO2, and ppm, the higher the chance for NO2 production.
NO2
Why is this toxic to humans?
- Leads to direct tissue damage
- This leads to increased pulmonary edema
What can be created from any drug that donates/delivers NO?
methemoglobin (dysfunctional form of Hemoglobin)
Less than 2% of Hb is methemoglobin
methemoglobin
How does this happen?
NO –><– Fe in hemoglobin
- Leads to Fe3+ from Fe2+
- This means the Fe cant attract O2, and O2 delivery is not present anymore
- Can lead to methemoglobinemia (picture)
NO
How do you take someone off NO when they have been receiving it for days or longer?
Slowly wean them off via multiple steps down.
NO
What happens if you take them off too quick?
- Vasoconstriction occurs again
- ↓ventilation = ↓O2 delivery = ↓O2 picked up = ↓PaO2 => Hypoxemia
Prostaglandins
What are they?
Drugs that exert effects locally, and last for short time.
Prostaglandins
What prostaglandin binds to PGI2 receptors? What drug is involved in this category?
- Prostacyclin (PGI2)
- Causes vasodilation
- Drug = Flolan (Epoprostenol)
Flolan (Epoprostenol)
What is it, and what are its onset and half life times?
- It’s an exogenous form of prostacyclin (PGI2)
- Onset: 1-2min
- 1/2 Life: 3-5min
Flolan (Epoprostenol)
How is it delivered and what is it used to treat?
- How –> Aerosolized + Inhaled
- Treat –> Pulmonary Hypertension
Note: Sticky + Protect from UV light
PDE-5 Inhibitors
What do they do? What is an example?
blue pill
- Cause Pulmonary vasodilation
- Ex –> VIAGRA!
PDE-5 Inhibitors
What drug falls under this category?
Sildenafil
Active ingredient in erectile dysfunction drugs
Sildenafil
What is it used for and how much is used/given?
- Pulmonary Hypertension (20mg)
- Viagra (25-100mg)
