/
AI Flashcards
Save to my account
Sign up
AI Flashcards
Fluid Balance and Diuretic Essentials
Study
1
Question
What percentage of total body weight is intracellular fluid (ICF) and what major ion predominates in it?
Page 1
Answer
Intracellular fluid (ICF) comprises approximately 40% of total body weight, and potassium (K+) is the major intracellular ion.
2
Question
What percentage of total body weight is extracellular fluid (ECF) and what are its main compartments?
Page 1
Answer
Extracellular fluid (ECF) comprises approximately 20% of total body weight and is divided among the vascular (plasma), interstitial, and transcellular fluid compartments.
3
Question
Define osmosis in the context of fluid movement between ICF and ECF.
Page 1
Answer
Osmosis is the movement of water between the extracellular fluid (ECF) and intracellular fluid (ICF) compartments driven by differences in solute concentration across cell membranes.
4
Question
What is the prototype loop diuretic and when are loop diuretics typically used?
Page 1
Answer
The prototype loop diuretic is furosemide. Loop diuretics are diuretics of choice when rapid, powerful diuresis is required, such as in pulmonary edema or acute fluid overload.
5
Question
List common adverse effects associated with loop diuretics.
Page 1
Answer
Common adverse effects include fluid and electrolyte imbalances (e.g., hyponatremia, hypokalemia), fluid volume depletion (FVD), and ototoxicity.
6
Question
What are key contraindications for using loop diuretics?
Page 1
Answer
Known hypersensitivity to the drug or anuria (absence of urine output) are contraindications. Also use caution in patients allergic to sulfonamides (for some agents) and when kidney function is severely impaired.
7
Question
What client education points are important when prescribing loop diuretics?
Page 1
Answer
Educate patients about the rationale for therapy, limiting sodium intake, monitoring daily weights and blood pressure, and recognizing signs of electrolyte imbalance. Timing (often morning dosing) and avoiding dehydration are important.
8
Question
What are thiazide diuretics pharmacologic class and main therapeutic uses?
Page 2
Answer
Thiazide diuretics belong to the thiazide class and are used therapeutically for management of hypertension (HTN) and edema. They act primarily at the distal convoluted tubule to decrease sodium and chloride reabsorption.
9
Question
Why should thiazide diuretics be used cautiously when glomerular filtration rate (GFR) decreases?
Page 2
Answer
Thiazide diuretics are less effective when GFR is decreased because urine flow and delivery of drug to the site of action are inadequate; they require adequate kidney function to produce diuresis.
10
Question
What is a common client instruction regarding timing of diuretic dosing before surgery and why?
Page 2
Answer
Diuretics are typically held on the morning of surgery to reduce the risk of volume depletion and electrolyte disturbances during the perioperative period.
11
Question
What is spironolactone's mechanism of action and its therapeutic classification?
Page 1
Answer
Spironolactone is a potassium-sparing diuretic that acts as an aldosterone antagonist, competing for the aldosterone-sensitive Na+/K+ channels in the distal tubule, thereby reducing aldosterone-induced retention of sodium and water and excretion of potassium. Therapeutically it is a diuretic and potassium-sparing agent.
12
Question
List major adverse effects and contraindications for spironolactone.
Page 1
Answer
Adverse effects include dizziness, headache, diarrhea, and increased serum potassium levels (hyperkalemia). Contraindications include presence of abnormal kidney function and pregnancy in the first trimester for some indications; avoid in patients with conditions that predispose to hyperkalemia.
13
Question
What client education is important for patients taking spironolactone?
Page 1
Answer
Advise taking the medication at the same time each day (usually morning), routine blood pressure and serum electrolyte monitoring, and avoiding potassium-rich foods and potassium-containing salt substitutes.
14
Question
What is the prototype osmotic diuretic and when is it used?
Page 1
Answer
The prototype osmotic diuretic is mannitol. It is used to produce rapid diuresis by increasing the solute (osmotic) load of the glomerular filtrate and is useful in managing oliguria or anuria and in reducing intracranial pressure (ICP) or intraocular pressure (IOP) in certain situations.
15
Question
What are indications for using loop diuretics in edema?
Page 3
Answer
Loop diuretics are indicated for edema related to congestive heart failure, cirrhosis of the liver, and renal disease; they are also used in the treatment of hypertension when needed for volume control.
16
Question
How do changes in capillary dynamics contribute to edema formation?
Page 3
Answer
Edema forms when there is an imbalance in capillary Starling forces: increased capillary hydrostatic (filtration) pressure, decreased capillary (plasma) colloid osmotic pressure, increased capillary permeability, or obstruction of lymph flow can all cause fluid accumulation in interstitial compartments.
17
Question
Name common causes of increased capillary hydrostatic pressure that lead to edema.
Page 3
Answer
Common causes include increased vascular volume (as in heart failure), venous obstruction, and venous thrombosis, all of which elevate capillary hydrostatic pressure and promote fluid filtration into tissues.
18
Question
Why does decreased plasma colloid osmotic pressure cause edema and what conditions produce this?
Page 4
Answer
Decreased plasma colloid osmotic pressure reduces the oncotic pull that normally returns fluid to capillaries, so fluid accumulates in the interstitium. Conditions producing this include hypoalbuminemia from liver disease or protein loss (e.g., nephrotic syndrome, severe malnutrition).
19
Question
How does increased capillary permeability contribute to edema?
Page 5
Answer
Increased capillary permeability (e.g., from inflammation, allergic reactions, burns) allows proteins and fluid to leak into the interstitial space, increasing interstitial oncotic pressure and promoting edema.
20
Question
What role does lymphatic obstruction play in edema?
Page 6
Answer
Obstruction of lymphatic flow prevents removal of interstitial fluid and proteins, leading to localized high-protein swelling (lymphedema). Causes include tissue injury, burns, surgical removal of lymph nodes, or malignant obstruction of lymphatic structures.
21
Question
Differentiate between localized and generalized edema with an example of each.
Page 9
Answer
Localized edema occurs in a specific anatomic site or space, for example, swelling in one lower extremity due to venous obstruction. Generalized edema (anasarca) is widespread, often due to increased vascular volume from heart failure, renal disease, or severe hypoalbuminemia.
22
Question
What is anasarca and when is it commonly seen?
Page 10
Answer
Anasarca is severe, generalized edema involving widespread subcutaneous tissue swelling and is frequently the result of greatly increased vascular volume. It is common in advanced heart failure, nephrotic syndrome, or severe liver disease with hypoalbuminemia.
23
Question
At which nephron site do thiazide diuretics primarily act and what ions do they affect?
Page 4
Answer
Thiazide diuretics primarily act on the distal convoluted tubule of the nephron, where they inhibit sodium and chloride reabsorption, leading to increased excretion of sodium and water and enhanced potassium excretion.
24
Question
What sensitivity or allergy should be considered before prescribing thiazide diuretics?
Page 4
Answer
Patients with known sensitivity to thiazides or sulfonamide-derived agents should be identified, as many thiazides are chemically related to sulfonamides and can cause hypersensitivity reactions.
25
Question
Why is careful position-change monitoring advised for patients on diuretics?
Page 2
Answer
Diuretics can cause volume depletion and hypotension (including orthostatic hypotension), so patients should be monitored for dizziness and posture-related drops in blood pressure when changing position.
26
Question
How does mannitol increase urine output and in which clinical situations is it particularly effective?
Page 1
Answer
Mannitol is an osmotic diuretic that increases the osmolarity of the glomerular filtrate, pulling water into the urine and producing rapid diuresis. It is effective in managing oliguria or anuria and in reducing intracranial pressure or protecting kidneys during certain nephrotoxic exposures (e.g., cisplatin infusion).
27
Question
What patient groups should avoid potassium-sparing diuretics like spironolactone?
Page 1
Answer
Patients with abnormal kidney function (impaired renal excretion of potassium), those at risk for hyperkalemia, and certain pregnant patients (depending on indication and trimester) should avoid or use caution with potassium-sparing diuretics like spironolactone.
28
Question
What monitoring is recommended for patients receiving diuretic therapy?
Page 2
Answer
Recommended monitoring includes routine blood pressure readings, daily weights, and periodic measurement of serum electrolytes (especially potassium and sodium), renal function tests, and awareness of signs of volume depletion or overload.
29
Question
Name common uses of loop diuretics beyond edema control.
Page 1
Answer
Beyond edema control, loop diuretics are used for acute conditions requiring rapid fluid removal such as pulmonary edema and situations where rapid diuresis is clinically necessary.
30
Question
Explain why diuretics can increase blood sugar levels in some patients.
Page 2
Answer
Some diuretics (particularly thiazides) can impair glucose tolerance and modestly raise blood glucose levels, possibly through effects on insulin secretion or sensitivity; patients should be monitored for changes in blood sugar.