Renal and Endocrine Flashcards
How does the angiotensin system work?
Blood pressure or fluid volume drops
Renin is released from kidneys which turns angiotensin to angiotensin I
ACE is released from the lungs which converts angiotensin I to angiotensin II (vasoconstrictor)
Angiotensin II acts on the adrenal gland to release aldosterone
Aldosterone acts on the kidneys to reabsorb salt and water which increases fluid volume and blood pressure
List 7 types of medication that treat hypertension
Central adrenergic medications Peripheral adrenergic inhibitors Arteriolar dilators Calcium channel blockers B-adrenergic blocking agents Diuretics Angiotensin-converting enzymes (ACE) Angiotensin-receptor antagonists (ARBs)
What does ABCDE stand for?
Ace inhibitors, angiotensin II receptor antagonists and alpha antagonists Beta blockers Calcium channel blockers Diuretics Endothelin receptor agonists
How do ACE inhibitors work?
They prevent angiotensin I turning into angiotensin II which is a powerful vasoconstrictor resulting in reduced peripheral vascular resistance and subsequently BP
Which suffix indicates ACE inhibitors?
Pril
What’s an ARB?
Angiotensin-receptor antagonist
What suffix indicates an ARB?
Sartan
How do ARBs work?
Antagonise angiotensin II receptors on vascular smooth muscles which increases renal blood flow and maintains or increases glomerular filtration rate while decreasing renal vascular resistance
ARBs indications
Hypertension in patients who are unable to tolerate ACEIs
ARBs interactions
Potassium sparing diuretics, NSAIDs
ARBs nursing considerations
Sodium or intravascular volume depletion should be corrected before therapy. Monitor serum creatinine and potassium
Which suffix indicates Alpha antagonists?
ocin
How do Alpha antagonists work?
They block the alpha receptors located on the arterioles and venules. These receptors mediate the peripheral vasoconstrictive response. Therefore the blockade lowers systemic vascular resistance
Alpha antagonist nursing considerations
Dose should start small and increase gradually to minimise risk of first dose hypotension. Advise patients to get up slowly to avoid orthostatic hypotension
Which electrolyte allows the kidneys to regulate fluid?
Sodium
Define preload
Initial stretching of the cardiac muscle cells prior to contraction which allows ventricular filling
Define afterload
The force or load against which the heart has to contract to eject blood from the heart
What are the three main types of diuretics?
Thiazide, High ceiling loop, Potassium-sparing
How do Thiazide diuretics work?
They increase the excretion of sodium and chloride ions and water in the proximal segment of the distal tubule
Thiazide diuretics indication
Primary therapy of hypertension in those above 65. Mild to moderate stable heart failure
What side effect is common across all diuretics?
Electrolyte imbalance
How do High-ceiling loop diuretics work?
They inhibit sodium and chloride reabsorption in the proximal and distal tubules especially in the ascending loop of Henle which leads to greater water excretion
How do Potassium-sparing diuretics work?
Aldosterone antagonists that inhibit in the distal convoluted distal tubule that increases the excretion of sodium and water but decreases potassium excretion
What’s BPH?
Benign Prostatic Hypertrophy. Enlarged prostate
