Term
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Definition
excess fluid in tissues
Hydrostatic pressure: created by fluid in closed
space |
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Term
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Definition
| created by plasma proteins |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
agents “..that increase renal
excretion of water, sodium, and other
electrolytes thereby increasing urine
formation and output” |
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Term
| Goals of Diuretic Therapy |
|
Definition
The most common reason for
giving diuretics is to eliminate
excess fluid, electrolytes, and/or
wastes. |
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Term
|
Definition
Although various classes of diuretics act in
different ways, they commonly increase
urine formation by
increasing the glomerular filtration rate and/or
decreasing reabsorption from renal tubules |
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Term
| Who would need a diuretic? |
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Definition
If you said, a person
who is retaining fluid,
you are correct.
Excess fluid in body
tissues is edema. |
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Term
| Some causes of edema are: |
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Definition
| Heart failure
Poor circulation
Renal failure
Diuretics might be used for all of these problems. |
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Term
Can you think of other conditions
that might be treated with
diuretics? |
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Definition
| Perhaps you know someone who has
hypertension (high blood pressure).
Diuretics often are used to treat
hypertension.
Go to
www.nih.gov/news/pr/dec2002/nhlbi-
1.7.htm to see recent recommendations
about the use of diuretics for
hypertension. |
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Term
Did you know that some diuretics can
lower the pressure in the eye, called
the intraocular pressure or IOL?
When might we want to reduce IOL? |
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Definition
| When IOL is abnormally
elevated
To soften the eye for
ophthalmic surgery |
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Term
|
Definition
| How many uses for diuretics do you
recall?
If necessary, go back and review the last 4
slides |
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Term
|
Definition
| As you might expect, the most
likely adverse effects of diuretic
therapy are fluid and electrolyte
imbalances including
Hypokalemia (most diuretics)
Fluid volume deficit and hypotension
Hyponatremia
Hyperglycemia |
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Term
Do you recognize the terms for
various fluid and electrolyte
imbalances? |
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Definition
| Remember, “hypo” means too little, and “hyper”
means too much.
Kal refers to potassium; cal to calcium; and natr
to sodium.
Vol refers to fluid volume
The suffix “-emia” refers to the blood.
So, hyperkalemia is high blood potassium, and
hypovolemia is low blood volume!
Other adverse effects are specific to certain
classes of diuretics. I will mention these as we
go along.
Now let’s talk about the various diuretic
classes. |
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Term
|
Definition
| Thiazides
High ceiling (loop)
Potassium sparing
Osmotic
Carbonic anhydrase inhibitors |
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Term
|
Definition
| These drugs act in the renal tubules to
decrease reabsorption of Na, Cl, K, Mg,
bicarbonate, water
increase reabsorption of glucose,
calcium, lipids
Our prototype for the thiazides is
hydrochlorozide (HCTZ) |
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Term
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Definition
| Not strong diuretic
Slow onset of action (2 hours)
Useful in treating elevated urine calcium
(hypercalciuria) because it causes tubules to
reabsorb calcium
Poor choice with diabetes because it
increases serum glucose and lipids
Risk of allergy in people who are allergic to
sulfonamides |
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Term
| High Ceiling (Loop) Diuretics |
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Definition
| These drugs act by decreasing the
reabsorption of Na, Cl, and Ca
The prototype for this class is
furosemide (Lasix) |
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Term
| Features of High Ceiling Diuretics |
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Definition
| Stronger, faster onset of action than
thiazides
Na restriction often is needed because of
post-diuretic rebound effect
Treats hypercalcemia: unlike thiazides,
these drugs increase calcium in the urine
Ototoxic, so assess hearing and balance |
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Term
| Potassium-Sparing Diuretics |
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Definition
| Action: These drugs are aldosterone
antagonists
Aldosterone normally promotes Na retention;
the drug prevents Na retention
K is not excreted in exchange for Na, so
excess K is not lost
Prototype: spironolactone (Aldactone) |
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Term
Features of Potassium Sparing
Diuretics |
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Definition
| The potential for hyperkalemia exists
Potassium supplements are not needed
Monitor heart rate and rhythm because
abnormal potassium affects the
conduction of cardiac nerve impulses and
myocardial contraction. |
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Term
|
Definition
| These drugs act by increasing
osmotic pressure in blood and in the
glomerular filtrate
The prototype is mannitol (Osmitrol)
Considerations
Uses: anuria, increased IOP, cerebral
edema
Risk of hypervolemia, then
hypovolemia |
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Term
| Features of Osmotic Diuretics |
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Definition
| Mannitol is given by the IV route only
It is used to treat
Anuria (absence of urine production)
Cerebral edema
Increased intraocular pressure
As excess fluid is drawn from the tissues into the
bloodstream, hypervolemia can occur.
As the kidneys excrete the mannitol, fluid is
excreted, possibly in excess resulting in
hypovolemia. |
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Term
It’s important to understand how osmotic
diuretics work, so let’s review what happens
when it is administered intravenously. |
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Definition
| Mannitol, which has a high molecular weight, is
delivered to the bloodstream where it increases
osmotic pressure.
The large molecules do not pass out of the blood into
body tissues.
By osmosis, mannitol causes water to move out of
edematous tissue into the bloodstream.
When blood circulates through the kidneys, mannitol
is excreted in the tubules so it becomes part of the
urine.
The osmotic pressure of the mannitol holds water
causing both to be eliminated. |
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Term
Carbonic Anhydrase
Inhibitors |
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Definition
| These drugs act by inhibiting
bicarbonate reabsorption
production of aqueous humor and
cerebrospinal fluid (CSF)
The prototype is acetazolamide
(Diamox) |
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Term
| Diuretics: Nursing Assessment |
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Definition
| Which of the following
data are needed when
patients are taking
diuretics?
Intake and output
Daily weights
Edema
Serum electrolytes
Neuromuscular status
Serum glucose
Mental status |
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Term
Did you select all options? If so, you are
right! Let’s review the usefulness of each
option. |
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Definition
Intake and output will help you determine
whether the patient is eliminating excess fluid.
You would expect output to exceed intake
during diuresis. This will be most apparent
when patients are retaining a lot of fluid.
When patients take diuretics long-term, fluid
intake and output may remain about equal. |
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Term
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Definition
this is a simple, useful way
to detect fluid loss or gain because body
mass changes very little from day to day.
Daily weights must be done on the same
scale and under the same conditions each
day in order to be useful. |
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Term
|
Definition
the accumulation of fluid in
tissues. Because water tends to flow
downhill, edema is most apparent in
dependent body areas. Check the ankles
of ambulatory patients and the backs of
bed patients. Auscultation of the lungs
may reveal pulmonary edema. Effective
diuretic therapy should cause edema to
decrease. |
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Term
|
Definition
reports reveal actual
blood levels and enable you to detect
abnormalities such as low potassium.
Notify the physician if values are
significantly abnormal. |
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Term
|
Definition
may have been a
less obvious choice to you. However,
impulse conduction and muscle activity
depend on specific concentrations of
electrolytes, especially potassium and
calcium. Therefore, assessment of
reflexes and muscle tone may yield
indicators of electrolyte imbalances. |
|
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Term
|
Definition
is most likely to be affected
by the thiazides. This is not usually
significant unless a patient has diabetes. |
|
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Term
|
Definition
is affected by fluid and
electrolyte balance. For example, fluid
excess can include cerebral edema which
causes confusion or decreased alertness.
A fluid deficit such as dehydration
decreases blood flow and also can cause
mental changes. |
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Term
Nursing Diagnoses and Interventions
for Patients on Diuretic Therapy |
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Definition
| Risk for deficient fluid volume r/t excess
diuresis (hypovolemia)
Your first role is to monitor for hypovolemia.
Some indicators include hypotension,
tachycardia, dry mucous membranes, and
concentrated urine.
You also may be administering fluid
replacement by oral and parenteral routes. |
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Term
| Decreased cardiac output r/t electrolyte
imbalances
Hypokalemia: |
|
Definition
assess for irregular pulse, hypotension,
weak respirations, muscle weakness, abdominal
distention. Administer potassium replacement
cautiously as ordered. ALWAYS DILUTE
POTASSIUM; GIVE SLOWLY!!!!!!! |
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Term
|
Definition
Assess for hypotension, tachycardia,
oliguria, confusion, abdominal cramps. |
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Term
| Risk for injury r/t abnormal serum
calcium
Hypocalcemia: |
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Definition
Assess for neuromuscular
irritability. Provide calcium replacement as
ordered |
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Term
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Definition
Assess for depressed
neuromuscular function. Encourage fluids to
prevent urinary calculi (stones). Administer
high ceiling diuretic as ordered. |
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Term
Deficient knowledge of diuretic
therapy. The patient teaching plan
should include: |
|
Definition
| Take diuretics in the morning to avoid nighttime
voiding
Report weakness, palpitations, muscle cramps,
confusion
Reduce sodium intake if ordered. This is not always
necessary or wise. Elderly patients are at risk for
sodium depletion.
Ask the physician before using salt substitutes. They
contain potassium. |
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Term
Diuretics are used for their ability to
promote the excretion of water and
___________ |
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Definition
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Term
The most serious adverse effects of most
diuretics is _______________ which can
cause fatal alterations in cardiac rhythm. |
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Definition
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Term
__________ diuretics are weak, slow, and
are not advised with diabetes because
they increase serum glucose and lipids. |
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Definition
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Term
High ceiling diuretics promote calcium
excretion whereas ___________ promote
calcium retention. |
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Definition
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Term
Patients taking ___________ diuretics
may also require sodium restriction
because of post-diuretic rebound effect. |
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Definition
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Term
Only potassium sparing diuretics place the
patient at risk for ___________ which also
can cause fatal cardiac disturbances. |
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Definition
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Term
______________ diuretics can cause fluid
excess initially. |
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Definition
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Term
The type of diuretic used to lower increased
intraocular pressure is _______. |
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Definition
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Term
Signs and symptoms of ____________ include
hypotension, tachycardia, dry mucous
membranes, and concentrated urine. |
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Definition
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Term
When a patient on diuretic therapy has an
irregular pulse, weakness, and abdominal
distention, you should suspect _____________. |
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Definition
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Term
Potassium that is administerd too rapidly
or in concentrated form can cause
_____________________. |
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Definition
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Term
Diuretics usually are given in the morning
to prevent _______________. |
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Definition
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|
Term
A patient on a potassium sparing diuretic
who uses salt substitutes is at risk for
_______________. |
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Definition
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