FLUID & ELECTROLYTE BALANCE, IV
THERAPY, AND RENAL FUNCTION: NCLEX-
STYLE QUESTIONS WITH CORRECT
ANSWERS AND RATIONALES (2025–2026)
A nurse is caring for a critically ill patient with a urinary retention catheter. Which hourly
urine output should first alert the nurse that the primary health-care provider should be
notified?
1. 20 mL
2. 30 mL
3. 60 mL
4. 120 mL - CORRECT ANSWERS-2. The circulating blood volume perfuses the
kidneys, producing a glomerular filtrate of which varying amounts are either reabsorbed
or excreted to
maintain fluid balance. When a person's hourly urine output is only 30 mL, it indicates a
deficient circulating fluid volume, inadequate renal perfusion, and/or kidney disease.
The primary health-care provider should be notified.
A nurse is caring for a patient who has dependent edema. Which pressure has caused
the excess fluid in the interstitial compartment?
1. Oncotic pressure
2. Diffusion pressure
3. Hydrostatic pressure
4. Intraventricular pressure - CORRECT ANSWERS-3. Hydrostatic pressure is the
pressure exerted by a fluid within a compartment, such as blood within the
, vessels. Hydrostatic pressure moves fluid from an area of greater pressure to an area of
lesser pressure.
Hydrostatic pressure within vessels of the body moves fluid from the intravascular
compartment into the interstitial compartment. Interstitial fluid is extracellular fluid that
surrounds cells.
A nurse evaluates a patient's fluid balance by monitoring the patient's intake and output.
Which must the nurse understand about the ratio of the patient's fluid intake to output?
1. Intake should be slightly more than the output.
2. Intake should be higher than the fluid output.
3. Intake should be lower than the urine output.
4. Intake should be equal to the urine output. - CORRECT ANSWERS-1. The volume
and composition of body fluids are kept in a delicate balance (total intake is slightly
more than total output) by a harmonious interaction of the kidneys and the endocrine,
respiratory, cardiovascular,
integumentary, and gastrointestinal systems.
Hydrochlorothiazide (HCTZ) , a diuretic, is prescribed for a patient who is retaining fluid.
The nurse should encourage the patient to ingest nutrients that contain which
electrolyte?
1. Magnesium
2. Potassium
3. Calcium
4. Sodium - CORRECT ANSWERS-2. Most diuretics affect the renal mechanisms for
tubular secretion and reabsorption of electrolytes, particularly potassium. Because of
potassium's narrow therapeutic window of 3.5 to 5.0 mEq/L and its role in the sodium-
potassium pump and muscle contraction, depleted potassium must be supplemented by
increasing the
dietary intake of foods high in potassium and/or the administration of potassium drug
therapy.
Which should a nurse do to encourage a confused patient to drink more fluid?
1. Serve fluid at a tepid temperature.
2. Explain the reason for the desired intake.
3. Offer the patient something to drink every hour.
4. Leave a pitcher of water at the patient's bedside. - CORRECT ANSWERS-3.
Frequent smaller volumes of fluid (50 to 100 mL/hr) are better tolerated physiologically
and psychologically than infrequent larger volumes of fluid.
A nurse suspects that an older adult may have a fluid and electrolyte imbalance. Which
assessment best reflects fluid and electrolyte balance in an older adult?
1. Intake and output results
2. Serum laboratory values
3. Condition of the skin
4. Presence of tenting - CORRECT ANSWERS-2. Laboratory studies provide objective
THERAPY, AND RENAL FUNCTION: NCLEX-
STYLE QUESTIONS WITH CORRECT
ANSWERS AND RATIONALES (2025–2026)
A nurse is caring for a critically ill patient with a urinary retention catheter. Which hourly
urine output should first alert the nurse that the primary health-care provider should be
notified?
1. 20 mL
2. 30 mL
3. 60 mL
4. 120 mL - CORRECT ANSWERS-2. The circulating blood volume perfuses the
kidneys, producing a glomerular filtrate of which varying amounts are either reabsorbed
or excreted to
maintain fluid balance. When a person's hourly urine output is only 30 mL, it indicates a
deficient circulating fluid volume, inadequate renal perfusion, and/or kidney disease.
The primary health-care provider should be notified.
A nurse is caring for a patient who has dependent edema. Which pressure has caused
the excess fluid in the interstitial compartment?
1. Oncotic pressure
2. Diffusion pressure
3. Hydrostatic pressure
4. Intraventricular pressure - CORRECT ANSWERS-3. Hydrostatic pressure is the
pressure exerted by a fluid within a compartment, such as blood within the
, vessels. Hydrostatic pressure moves fluid from an area of greater pressure to an area of
lesser pressure.
Hydrostatic pressure within vessels of the body moves fluid from the intravascular
compartment into the interstitial compartment. Interstitial fluid is extracellular fluid that
surrounds cells.
A nurse evaluates a patient's fluid balance by monitoring the patient's intake and output.
Which must the nurse understand about the ratio of the patient's fluid intake to output?
1. Intake should be slightly more than the output.
2. Intake should be higher than the fluid output.
3. Intake should be lower than the urine output.
4. Intake should be equal to the urine output. - CORRECT ANSWERS-1. The volume
and composition of body fluids are kept in a delicate balance (total intake is slightly
more than total output) by a harmonious interaction of the kidneys and the endocrine,
respiratory, cardiovascular,
integumentary, and gastrointestinal systems.
Hydrochlorothiazide (HCTZ) , a diuretic, is prescribed for a patient who is retaining fluid.
The nurse should encourage the patient to ingest nutrients that contain which
electrolyte?
1. Magnesium
2. Potassium
3. Calcium
4. Sodium - CORRECT ANSWERS-2. Most diuretics affect the renal mechanisms for
tubular secretion and reabsorption of electrolytes, particularly potassium. Because of
potassium's narrow therapeutic window of 3.5 to 5.0 mEq/L and its role in the sodium-
potassium pump and muscle contraction, depleted potassium must be supplemented by
increasing the
dietary intake of foods high in potassium and/or the administration of potassium drug
therapy.
Which should a nurse do to encourage a confused patient to drink more fluid?
1. Serve fluid at a tepid temperature.
2. Explain the reason for the desired intake.
3. Offer the patient something to drink every hour.
4. Leave a pitcher of water at the patient's bedside. - CORRECT ANSWERS-3.
Frequent smaller volumes of fluid (50 to 100 mL/hr) are better tolerated physiologically
and psychologically than infrequent larger volumes of fluid.
A nurse suspects that an older adult may have a fluid and electrolyte imbalance. Which
assessment best reflects fluid and electrolyte balance in an older adult?
1. Intake and output results
2. Serum laboratory values
3. Condition of the skin
4. Presence of tenting - CORRECT ANSWERS-2. Laboratory studies provide objective
