ATI Medical-Surgical Fluid and Electrolytes
Exam Questions with Correct Answers
(VerifiedAnswers) Plus Rationales 2026 Q&A
Instant Download PDF
Question 1
A nurse is assessing a client who has a serum sodium level of
124 mEq/L. Which finding should the nurse expect?
A. Increased thirst and dry mucous membranes
B. Confusion and headache
C. Bounding peripheral pulses
D. Increased deep tendon reflexes
Rationale: A sodium level of 124 mEq/L indicates significant
hyponatremia. Sodium is the major extracellular cation and has
an important role in regulating extracellular fluid osmolality.
When sodium falls substantially, water can shift into brain cells,
producing neurologic manifestations such as headache,
confusion, lethargy, seizures, and decreased level of
consciousness. Severe or rapidly developing hyponatremia is
particularly dangerous because cerebral edema can occur.
,Increased thirst and dry mucous membranes are more
consistent with fluid volume deficit or hypernatremia, while
bounding pulses are associated more with fluid volume excess.
Question 2
A client has a potassium level of 2.8 mEq/L. Which ECG finding
should the nurse anticipate?
A. Peaked T waves
B. Widened QRS complexes
C. Prominent U waves
D. Shortened QT interval
Rationale: A potassium level below the expected range indicates
hypokalemia. Hypokalemia alters cardiac repolarization and can
produce flattened or inverted T waves, prominent U waves, ST-
segment depression, and dysrhythmias. Peaked T waves and
QRS widening are more characteristic of significant
hyperkalemia. Because severe potassium abnormalities can
cause life-threatening dysrhythmias, cardiac monitoring and
prompt correction of the underlying cause are important.
Question 3
,A nurse is caring for a client with a potassium level of 6.7 mEq/L
and peaked T waves. Which medication should the nurse
anticipate administering first to stabilize the myocardium?
A. Regular insulin only
B. Sodium polystyrene sulfonate
C. Furosemide
D. IV calcium gluconate
Rationale: Severe hyperkalemia accompanied by ECG changes is
an emergency because elevated potassium can cause
potentially fatal cardiac dysrhythmias. IV calcium gluconate
does not remove potassium from the body or substantially
lower the serum potassium concentration; instead, it
temporarily stabilizes the cardiac membrane and reduces the
immediate risk of dysrhythmia. After myocardial stabilization,
therapies such as insulin with dextrose can shift potassium into
cells, while other treatments remove potassium from the body.
Question 4
Which assessment finding is most consistent with fluid volume
deficit?
A. Crackles
B. Bounding pulse
, C. Jugular venous distention
D. Orthostatic hypotension
Rationale: Fluid volume deficit occurs when fluid losses exceed
intake. Decreased intravascular volume can cause reduced
venous return and cardiac output, producing orthostatic
hypotension, tachycardia, weak peripheral pulses, dry mucous
membranes, decreased urine output, and weight loss. Crackles,
jugular venous distention, and bounding pulses are more
characteristic of fluid volume excess.
Question 5
A client with heart failure has gained 2.5 kg over several days.
Which interpretation should the nurse make?
A. The client has lost approximately 2.5 L of fluid.
B. The weight change is expected with aging.
C. The client has likely retained approximately 2.5 L of fluid.
D. The weight gain indicates an electrolyte deficit only.
Rationale: Daily body weight is one of the most sensitive
indicators of changes in fluid balance. Approximately 1 kg of
acute body-weight change is commonly associated with about 1
L of fluid. Therefore, a 2.5-kg increase over a short period
strongly suggests approximately 2.5 L of fluid retention,
although other causes of weight change must be considered. In
Exam Questions with Correct Answers
(VerifiedAnswers) Plus Rationales 2026 Q&A
Instant Download PDF
Question 1
A nurse is assessing a client who has a serum sodium level of
124 mEq/L. Which finding should the nurse expect?
A. Increased thirst and dry mucous membranes
B. Confusion and headache
C. Bounding peripheral pulses
D. Increased deep tendon reflexes
Rationale: A sodium level of 124 mEq/L indicates significant
hyponatremia. Sodium is the major extracellular cation and has
an important role in regulating extracellular fluid osmolality.
When sodium falls substantially, water can shift into brain cells,
producing neurologic manifestations such as headache,
confusion, lethargy, seizures, and decreased level of
consciousness. Severe or rapidly developing hyponatremia is
particularly dangerous because cerebral edema can occur.
,Increased thirst and dry mucous membranes are more
consistent with fluid volume deficit or hypernatremia, while
bounding pulses are associated more with fluid volume excess.
Question 2
A client has a potassium level of 2.8 mEq/L. Which ECG finding
should the nurse anticipate?
A. Peaked T waves
B. Widened QRS complexes
C. Prominent U waves
D. Shortened QT interval
Rationale: A potassium level below the expected range indicates
hypokalemia. Hypokalemia alters cardiac repolarization and can
produce flattened or inverted T waves, prominent U waves, ST-
segment depression, and dysrhythmias. Peaked T waves and
QRS widening are more characteristic of significant
hyperkalemia. Because severe potassium abnormalities can
cause life-threatening dysrhythmias, cardiac monitoring and
prompt correction of the underlying cause are important.
Question 3
,A nurse is caring for a client with a potassium level of 6.7 mEq/L
and peaked T waves. Which medication should the nurse
anticipate administering first to stabilize the myocardium?
A. Regular insulin only
B. Sodium polystyrene sulfonate
C. Furosemide
D. IV calcium gluconate
Rationale: Severe hyperkalemia accompanied by ECG changes is
an emergency because elevated potassium can cause
potentially fatal cardiac dysrhythmias. IV calcium gluconate
does not remove potassium from the body or substantially
lower the serum potassium concentration; instead, it
temporarily stabilizes the cardiac membrane and reduces the
immediate risk of dysrhythmia. After myocardial stabilization,
therapies such as insulin with dextrose can shift potassium into
cells, while other treatments remove potassium from the body.
Question 4
Which assessment finding is most consistent with fluid volume
deficit?
A. Crackles
B. Bounding pulse
, C. Jugular venous distention
D. Orthostatic hypotension
Rationale: Fluid volume deficit occurs when fluid losses exceed
intake. Decreased intravascular volume can cause reduced
venous return and cardiac output, producing orthostatic
hypotension, tachycardia, weak peripheral pulses, dry mucous
membranes, decreased urine output, and weight loss. Crackles,
jugular venous distention, and bounding pulses are more
characteristic of fluid volume excess.
Question 5
A client with heart failure has gained 2.5 kg over several days.
Which interpretation should the nurse make?
A. The client has lost approximately 2.5 L of fluid.
B. The weight change is expected with aging.
C. The client has likely retained approximately 2.5 L of fluid.
D. The weight gain indicates an electrolyte deficit only.
Rationale: Daily body weight is one of the most sensitive
indicators of changes in fluid balance. Approximately 1 kg of
acute body-weight change is commonly associated with about 1
L of fluid. Therefore, a 2.5-kg increase over a short period
strongly suggests approximately 2.5 L of fluid retention,
although other causes of weight change must be considered. In
