Ch 48 Flashcards
diuretic purposes
- decrease HTN
2. decrease edema (peripheral or pulmonary)
how do diuretics work
Produce increased urine flow (diuresis) by inhibiting sodium and water reabsorption from kidney tubules. Can affect one or more segments of the renal tubules. Particles such as electrolytes, drugs, glucose, and waste form protein metabolism, and are filtered in the glomeruli. Protein and blood cells are not filtered with normal renal function, and return to normal circulation.
decrease in fluid volume>lowered blood pressure.
!!!!Most diuretics cause loss of electrolytes including potassium, magnesium, chloride Antihypertensive effects caused by promotion of sodium and water loss by blocking sodium and chloride reabsorption, and bicarbonate!!!!!
what do thiazides/thiazide like diuretics act on? what do they do?
Acts on distal convoluted renal tubule, beyond loop of Henle promoting sodium, potassium, magnesium, water, and chloride excretion.
Promote calcium reabsorption causing risk for !!hypercalcemia!!.
!!Affect glucose tolerance, which may cause hyperglycemia!!
Used to treat hypertension and edema, but not effective for immediate diuresis, and !!cannot be used in patient’s with impaired renal function!!
hydrochlorothiazide HCTZ PD/PT
act on renal distal tubules: promote Na, K, H20 excretion to decrease preload, CO. decreases edema, acts on arterioles, causing vasodilation»_space; decreases BP. PT: edema from HF and hepatic cirrhosis, inc urine ouptut, HTN.
hydrochlorothiazide HCTZ CI/PREC/ADV/SE/DFL/NI/PTED
CI: renal
PREC: sle, gout, dm, renal/hepatic, electrolyte imbalance, hypotn
ADV: ortho hypo, gout, hyponatremia. LIFE THREATS: severe hypokalemia, blood disorders, renal failure, SJ.
SE: n/v/d/c/abd pain. dizzy/headache/vertigo/blurry vision.
muscle cramp/paresthesia.
hyperglycemia.
rash/photosensitivity.
hyperuricemia.
DFL: drugs-inc digitalis tox if hypokalemic. inc renal tox with ASA. inc K loss with steroids. dec eff of antidiabetics. dec thiazide absorption and effects with NSAIDS.
lab-inc serum Ca, glucose, uric acid, decreased serum K, Na, Mg
NI: assess vitals, WEIGHT, ELECTROLYTES, BG, URIC ACID as baseline.
assess/monitor peripheral edema and improvement. monitor pt weight (fluid retention: increase of 2.2lb equal 1L of body fluid). monitor output. monitor if pt uses digoxin or if hypokalemic due to risk of tox. assess/monitor for s/s of hypokalemia (norm K 3.5-5). s/s=muscle weakness, leg cramps, cardiac dysrhythm.
pt ed: teach pt or fam take BP, check/record before med. take early morning (prevent nocturia)
rise slowly (ortho hypo)
sun precautions
monitor BG.
eat K rich food if not currently taking with potassium sparing diuretic.
monitor weight, edema. if SOB, diff breathing, or exercise intolerant tell DOC.
loop diuretics (high ceiling)
Act on the loop of Henle to inhibit chloride transport of sodium into the circulation>inhibits passive reabsorption of sodium
-Excretion of calcium, potassium and magnesium
Loop diuretics can affect blood sugar, and increase uric acid levels
These drugs cause potent diuresis, and depletion of water and electrolytes > often called high-ceiling or potassium-wasting diuretics
Effects are dose related
Should not be utilized if thiazide diuretics are sufficient in removing fluids > if Lasix alone is ineffective, then a thiazide can be added
Can increase renal blood flow up to 40%
furosemide (Lasix)
loop diuretic.
PD: Inhibition of sodium and water reabsorption from loop of Henle, and distal renal tubules causing excretion of calcium, magnesium, and potassium
PT: Cirrhosis, Hypertension, Renal dysfunction, Acute pulmonary edema, Fluid retention/fluid overload
LASIK all other stuff
CI: Presence of severe electrolyte imbalance, hypovolemia, anuria, hepatic coma, hypersensitivity to sulfonamides
Prec: HF, DM, HYPOTN, SLE, gout, and hearing impairment
ADV: severe dehydration, marked hypotension, hyperglycemia, gout, hearing loss
-Life threatening: Renal failure, thrombocytopenia, agranulocytosis
SE: n/d/c/abd cramping, electrolyte imbalance/ECG changes, headache/blurry vision/vertigo, rash/photosens, weakness/muscle cramping
Drug: increases bleeding with anticoagulants, Increased potassium loss with steroids, amphotericin B, and amiodarone.
Increases digitalis toxicity and cardiac dysrhythmias if hypokalemic, Can increase lithium toxicity
Labs: Increase in BUN, blood/urine glucose, serum uric acid, ammonia. Decrease in potassium, sodium, calcium, magnesium, and chloride
NI: base VS and monitor: Can decrease blood pressure.
Assess electrolytes for baseline.
assess/monitor for peripheral edema and improvement of symptoms.
Monitor weight for fluid retention (Increase of 2.2 pounds>equivalent to 1L of body fluids).
Monitor patient closely if concurrent use of digoxin and hypokalemia due to risk of toxicity
Assess and monitor for signs and symptoms of hypokalemia
Normal potassium: 3.5-5
Hypokalemia: muscle weakness, leg cramps, cardiac dysrhythmias
ix. Patient Teaching
1. Educate patient/family how to take blood pressure> need to check blood pressure before taking medication
2. Best time to take medication is in the early morning to prevent nocturia
a. Educate patient the medication is a potent diuretic, and to anticipate the need to urinate
b. Implement safety precautions
3. Rise slowly from sitting to standing to prevent orthostatic hypotension
4. Eat potassium rich foods if not concurrently taking with a potassium-sparing diuretic
5. Monitor weight, and presence of edema
a. If becoming short of breath, difficulty breathing, or exercise intolerance notify healthcare provider
osmotic diuretics
Increase osmolality (concentration) and sodium reabsorption in proximal tubule, and loop of Henle. Used to prevent kidney failure, decrease intracranial pressure, and to decrease intraocular pressure (glaucoma)
mannitol
osmotic diuretic
PD: potent osmotic potassium wasting diuretic.
PT: 1. Emergency situations for increase ICP and IOP
2. Can be combined with chemotherapy to promote diuresis, and decrease side effects of medications
3. Most frequently prescribed osmotic diuretic
mannitol ci, ADV/SE, NI, pt ed
CI: Heat failure, Heart disease.
ADV/SE: Fluid and electrolyte imbalance, Nausea, vomiting, tachycardia, acidosis, Pulmonary edema from rapid shift of fluids
NI: Administer IV with a filter. Mannitol may crystallize in the vial, warm to dissolve crystals
-Do not administer if crystals are present
PT ED: Mannitol will cause diuresis, stimulating large quantities of urination
carbonic anhydrase inhibitors
Block the action of the enzyme carbonic anhydrase > needed to maintain body’s acid-base balance (hydrogen and bicarbonate) > inhibition > increased sodium, potassium, and bicarbonate excretion. Class of drugs is primarily used to decrease intraocular pressure in patients with chronic open-angle glaucoma
- Cannot be used with narrow-angle or acute glaucoma
ex: acetazolamide (Diamox), methazolamide (Neptazane)
potassium sparing diuretics
Weaker than thiazides, and loop diuretics. Used as a mild diuretic or in combination with another diuretic. Act primarily in the collecting duct renal tubules, and late distal tubule to promote sodium and water excretion, and potassium retention
- Interference with sodium-potassium pump controlled by mineralocorticoid hormone aldosterone. Can cause hyperkalemia, and needs to be periodically monitored if taken continuously
ex: spironolactone, amiloride, triamterene, eplerenone
spironolactone (aldactone) PD/PT/CI
pd: Blocks action of aldosterone (aldosterone antagonist), and inhibits sodium-potassium pump PT: 1. Hepatic cirrhosis 2. Nephrotic syndrome 3. Increase urine output 4. Treat fluid retention/overload CI: hyperkalemia, renal failure prec: DM, renal/hepatic, HF
spironolactone (aldactone) adv, se, dfl, ni, pt ed
adv(life threat): Thrombocytopenia, agranulocytosis, Severe hyperkalemia, Hepatotoxicity, Stevens-Johnson Syndrome.
SE: n/v/d, rash, headache/dizzy, weak, muscle cramps
drug: ^serum K w/K supps, ^eff of antihypertensives/lithium, hyperkalemia with ACE inhibitors.
lab: ^K, ^BUN,AST,ALP.
vNa, Cl
NI: assess meds (no K supps or ACE-I.) assess VS, weight, output (should increase), serum electrolytes, monitor thru therapy. assess/monitor s/s hyperkalemia.
if urine <30ml/hr or 600ml/day report.
pt ed: pt or fam take BP before med. rise slow, ortho hypo. avoid K foods or K supps. monitor weight/edema, should be improving. avoid direct sun. take med in mornings to avoid nocturia.
