Lesson 4: Vasodilators and Diuretics Flashcards
What are the two types of pulmonary vasodilators?
Inhaled Nitric Oxide
Synthetic Prostacyclins
What are the two FDA approved synthetic prostacyclins?
Illoprost (Ventavis)
Treprostinil (Tyvaso)
What synthetic prostacyclin is not FDA approved for pulmonary hypertension
Epoprostenol (Flovan)
What is the normal pulmonary artery pressure
10-15 mmHg
What pressure level is considered pulmonary hypertension
> 20 mmHg
What is nitric oxide and natural product of?
Endothelial cells because they cause vasodilation
What disease states is nitric oxide used in ?
Persistant Pulmonary Hypertension of the Newborn(PPHN)
ARDS
What is nitric oxide approved to be used for in regards to neonates?
Hypoxic respiratory failure
What is the recommended dosage of INO?
20 ppm
What does INO stimulate
cGMP production, which decreases intracellular Ca++
What does cGMP production result in
smooth muscle relaxation
What is the therapeutic benefit of INO
Improved blood flow to ventilated alveoli resulting in improved V/Q mismatch
Nitric Oxide is quickly oxidized into what?
NO2, which is more toxic
What level of NO2 is toxic, what is a safe level
10 ppm, 5 ppm is safe
Methemoglobin is a byproduct of INO binding to what?
Hemoglobin
What is the normal methemoglobin level?
0-2%
At what level do you treat high methemoglobin and what do you use to treat it
levels >30% and methylene blue
Oxidation index formula (OI)
Mean airway pressure cmH20 x (FiO2/PaO2)
What is a good OI
Closer to 0 the better
Iloprost (Ventavis) and Treprostinil (Tyvaso) both treat what? And are not approved for who?
Treat pulmonary hypertension and are not studied in asthmatics or peoples with COPD
What device does Iloprost (Ventasvis) use?
I-neb AAD
What device does the Tyvaso use? What two forms can it be given as?
Tyvaso Inhalation system (ultrasonic neb)
Can be given as DPI and aerosol
What percent of the cardiac output goes through the kidneys
22%
The kidneys have a high oxygen consumption, so impaired circulation can cause what?
Renal failure and damage
What is the functional unit of the kidney?
Nephron
What does the nephron do?
Maintains homeostasis of fluid volume and electrolyes
How many nephrons does each kidney have? How many nephrons have to be compromised before renal disease is apparent?
Each kidney has 2 million nephrons
Approx. 75% need to be compromised
What is the goal of diuretics
Reduce the extracellular fluid volume to decrease blood pressure
What are the 5 major groups of diuretics
Osmotic
CAI
Thiazides
Loop
Potassium Sparing
What are the four types of Osmotic diuretics
Glycerin
Isosorbide
Mannitol (preferred)
Urea
The main indication for osmotic diuretics is what?
TBI with cerebral edema
Mannitol DPI brand name is what
Aridol
Mannitol is used for what test?
Bronchial challenge test to diagnose asthma
What doe CAI s do
Inhibit carbonic anhydrase, which keeps sodium in the proximal tubule, and thus water in the proximal tubule, where it will eventually continue through the system and get excreted as urine
What is the strength of CAIs
Weak diuretics
What are CAIs used to treat
Aggressive management of hypervolemia
Metabolic alkalosis
Glaucoma
Altitude sickness
What are 3 types of CAIs
Acetazolamide
Methazolamide
Dicholarphenamide
Loops diuretics are also called what?
High ceiling, because theyre so powerful
Loop diuretics can cause up to how much NaCl and H2O loss?
20%
Higher doses of loop diuretics may be needed because of what?
Patients with renal dysfunction have less meds reach the site of action within the nephron
What are indications for loop diuretics
Hypertension
CHF
Acute renal failure
Chronic renal failure
Ascites
Nephrotic syndrome
Loop med names
Furosemide (Lasix)
Bumetanide (Bumex)
Torsemide (Demadex)
Ethacrynic acid
Thiazide diuretics is considered what potency
Moderate because 5-10% of NaCl is reabsorbed
What is Thiazide diuretics a first line agent for?
Mild hypertension
What is the limited dose response curve
Difference in therapeutic effect is small between minimal and max doses. Higher doses may not produce greater effects, but may increase risk of toxicity
Thiazide meds include
Chlorothiazide
Chlorthalidone
Indapamide
Potassium sparing diuretics block the exchange of what
Na and K / H in distal convoluted tubule, or by acting as an antagonist at the aldosterone receptor, more potassium stays in the blood, and can lead to hyperkalemia.
If someone becomes hyperkalemic on potassium sparing diuretics what treats it?
Thiazide bc they cause hypokalemia
What potassium sparing meds treat chronic liver disease
Spironolactone
Eplerenone
What potassium sparing meds treat CHF with counteracting hypokaemic affect of other diuretics
Amiloride
Trimterene
Glucose changes is most often seen with what diuretics
Thiazide
Ototoxicity is most often seen with what diuretics
Loop
