Fluid and Electrolyte Balance: Part 1 Flashcards
Functions of the kidney
Cleansing and maintenance of extracellular fluid volume and composition (ECF)
Electrolytes hugely impacted by kidneys
Potassium, chloride and sodium
Three renal processes effecting ECF
Filtration
Reabsorption
Secretion
Filtration is a ______ process and occurs in the ________
Nonselective
Glomerulus
Reabsorption includes…
99% water, electrolytes and nutrients
What determines concentration and composition of urine?
Reabsorption
How do diuretics primarily work?
By disrupting solute reabsorption at specific sites on the nephron
What percent of reabsorption occurs at the proximal convoluted tubule?
65%
Potassium sparing diuretics work ______ from the glomerulus
Farther
Diuretics block..
Na+ and Cl- reabsorption which prevents passive reabsorption of H2O, allowing H20 to be excreted
Carbonic anhydrase inhibitors
Work closest to the glomerulus, most potent diuretics that we have, used as eyedrops for glaucoma
Diuretics can cause,, (adverse effects)
Hypovolemia
Acid-base imbalances
Disturbance of electrolyte levels
Classification of diuretics
Loop / High ceiling Thiazide Osmotic Potassium sparing Carbonic anhydrase (lower intraocular pressure)
Loop diuretics are the most…
Effective (Diuresis occurs even when GFR is low)
Furosemide (Lasix) is most…
Commonly prescribed
Lasix: PO action within..
60 min
Lasix: IV action begins in _____; lasts ______
5 minutes
2 hours
IV Lasix dosage
Give 20-40mg over 1-2 minutes or infusion of 4mg / min
Loop diuretics therapeutic uses
- When massive fluid loss is necessary
- Congestive heart failure
- Cardiac or renal insufficiency
- Hypertension
Loops - CHF
Decreases some of the need for the heart to push a large amount of fluid through the body
Adverse effects of loop diuretics
Hyponatremia, dehydration, hypotension, hypokalemia, ototoxicity, hyperglycemia
Because of ototoxicity, loops should not be used with…
Aminoglycosides
Loops drug interactions
Potassium sparing diuretics (+) Antihypertensive agents (+) Ototoxic drugs (-) Lithium (-) NSAIDS (-) Digoxin (-)
Loops and Lithium
Lithium used for Bipolar / Schizophrenia; loops increase lithium toxicity (making people feel like they are losing their minds)