ACTUAL ATI MED-SURG CMS EXAM QUESTIONS &
ANSWERS COMPLETE CONTENT MASTERY SERIES
BLUEPRINT GUIDE (2026-2027 UPDATE)
This premium study guide delivers high-yield actual questions,
verified answers, and comprehensive expert rationales designed
to mirror the updated 2026-2027 ATI Adult Medical Surgical
Nursing Content Mastery Series (CMS) Exam. Every question
breaks down critical nursing concepts like fluid resuscitation,
laboratory interpretations, and post-operative care to ensure
top-tier preparation. Master high-traffic NCLEX-RN blueprints
seamlessly and secure an A+ on your very first attempt with this
definitive exam resource.
Fluid, Electrolyte, and Acid-Base Imbalances
(Questions 1-10)
Q1. A nurse is assessing a client who has severe
fluid volume deficit. Which of the following
laboratory findings should the nurse expect?
A. Decreased hematocrit
B. Decreased urine specific gravity
C. Elevated Blood Urea Nitrogen (BUN)
D. Decreased serum sodium
Correct Answer: C
Rationale: Dehydration leads to hemoconcentration
and decreased renal perfusion, both of which cause
an elevation in BUN levels. Hematocrit and urine
,specific gravity would increase, not decrease.
Serum sodium typically increases (hypernatremia)
due to hemoconcentration.
Q2. A nurse is caring for a client who has a fluid
volume deficit. Which of the following prescribed
intravenous solutions should the nurse anticipate
administering to rapidly expand intravascular
volume?
A. 0.45% Sodium Chloride
B. 0.9% Sodium Chloride
C. 5% Dextrose in 0.45% Sodium Chloride
D. Dextrose 10% in Water
Correct Answer: B
Rationale: 0.9% Sodium Chloride (Normal Saline) is
an isotonic solution. It has the same osmolarity as
extracellular fluid, making it ideal for rapidly
expanding intravascular volume. 0.45% NaCl is
hypotonic and shifts fluid out of vessels into cells.
Q3. A nurse is assessing a client who has a serum
potassium level of 2.8 mEq/L. Which of the following
findings should the nurse expect on the client's
electrocardiogram (ECG)?
A. Tall, peaked T waves
B. Widened QRS complexes
,C. Prominent U waves
D. ST-segment elevation
Correct Answer: C
Rationale: Hypokalemia (potassium < 3.5 mEq/L)
characteristically causes flattening of the T wave,
ST-segment depression, and the appearance of
prominent U waves. Peaked T waves and widened
QRS complexes are signs of severe hyperkalemia.
Q4. A nurse is caring for a client who has severe
hypokalemia and is receiving intravenous
potassium chloride via a peripheral IV. Which of the
following actions is the priority for the nurse?
A. Ensure the infusion rate does not exceed 10
mEq/hr.
B. Verify the client's urine output is at least 20
mL/hr.
C. Apply a warm compress to the IV site to reduce
localized burning.
D. Check the serum potassium level every 12 hours.
Correct Answer: A
Rationale: Intravenous potassium chloride must be
strictly controlled to prevent fatal arrhythmias; it
should never exceed 10 mEq/hr through a
peripheral line. While checking urine output is vital,
, the minimum safe output threshold is 30 mL/hr, not
20 mL/hr.
Q5. A nurse is assessing a client who has a serum
sodium level of 118 mEq/L. Which of the following
clinical manifestations should the nurse prioritize
for immediate safety interventions?
A. Dry, sticky mucous membranes
B. Intense thirst and oliguria
C. Altered mental status and generalized seizures
D. Decreased deep tendon reflexes
Correct Answer: C
Rationale: Severe hyponatremia (< 120 mEq/L)
causes rapid swelling of brain cells, resulting in
increased intracranial pressure, altered mental
status, confusion, and life-threatening seizures. Dry
mucous membranes and intense thirst are classic
signs of hypernatremia.
Q6. A nurse is reviewing the arterial blood gas
(ABG) results of a client who has been vomiting
continuously for 24 hours. The results are: pH 7.51,
PaCO2 44 mmHg, HCO3 34 mEq/L. The nurse should
interpret these findings as which of the following
acid-base imbalances?
A. Respiratory acidosis
ANSWERS COMPLETE CONTENT MASTERY SERIES
BLUEPRINT GUIDE (2026-2027 UPDATE)
This premium study guide delivers high-yield actual questions,
verified answers, and comprehensive expert rationales designed
to mirror the updated 2026-2027 ATI Adult Medical Surgical
Nursing Content Mastery Series (CMS) Exam. Every question
breaks down critical nursing concepts like fluid resuscitation,
laboratory interpretations, and post-operative care to ensure
top-tier preparation. Master high-traffic NCLEX-RN blueprints
seamlessly and secure an A+ on your very first attempt with this
definitive exam resource.
Fluid, Electrolyte, and Acid-Base Imbalances
(Questions 1-10)
Q1. A nurse is assessing a client who has severe
fluid volume deficit. Which of the following
laboratory findings should the nurse expect?
A. Decreased hematocrit
B. Decreased urine specific gravity
C. Elevated Blood Urea Nitrogen (BUN)
D. Decreased serum sodium
Correct Answer: C
Rationale: Dehydration leads to hemoconcentration
and decreased renal perfusion, both of which cause
an elevation in BUN levels. Hematocrit and urine
,specific gravity would increase, not decrease.
Serum sodium typically increases (hypernatremia)
due to hemoconcentration.
Q2. A nurse is caring for a client who has a fluid
volume deficit. Which of the following prescribed
intravenous solutions should the nurse anticipate
administering to rapidly expand intravascular
volume?
A. 0.45% Sodium Chloride
B. 0.9% Sodium Chloride
C. 5% Dextrose in 0.45% Sodium Chloride
D. Dextrose 10% in Water
Correct Answer: B
Rationale: 0.9% Sodium Chloride (Normal Saline) is
an isotonic solution. It has the same osmolarity as
extracellular fluid, making it ideal for rapidly
expanding intravascular volume. 0.45% NaCl is
hypotonic and shifts fluid out of vessels into cells.
Q3. A nurse is assessing a client who has a serum
potassium level of 2.8 mEq/L. Which of the following
findings should the nurse expect on the client's
electrocardiogram (ECG)?
A. Tall, peaked T waves
B. Widened QRS complexes
,C. Prominent U waves
D. ST-segment elevation
Correct Answer: C
Rationale: Hypokalemia (potassium < 3.5 mEq/L)
characteristically causes flattening of the T wave,
ST-segment depression, and the appearance of
prominent U waves. Peaked T waves and widened
QRS complexes are signs of severe hyperkalemia.
Q4. A nurse is caring for a client who has severe
hypokalemia and is receiving intravenous
potassium chloride via a peripheral IV. Which of the
following actions is the priority for the nurse?
A. Ensure the infusion rate does not exceed 10
mEq/hr.
B. Verify the client's urine output is at least 20
mL/hr.
C. Apply a warm compress to the IV site to reduce
localized burning.
D. Check the serum potassium level every 12 hours.
Correct Answer: A
Rationale: Intravenous potassium chloride must be
strictly controlled to prevent fatal arrhythmias; it
should never exceed 10 mEq/hr through a
peripheral line. While checking urine output is vital,
, the minimum safe output threshold is 30 mL/hr, not
20 mL/hr.
Q5. A nurse is assessing a client who has a serum
sodium level of 118 mEq/L. Which of the following
clinical manifestations should the nurse prioritize
for immediate safety interventions?
A. Dry, sticky mucous membranes
B. Intense thirst and oliguria
C. Altered mental status and generalized seizures
D. Decreased deep tendon reflexes
Correct Answer: C
Rationale: Severe hyponatremia (< 120 mEq/L)
causes rapid swelling of brain cells, resulting in
increased intracranial pressure, altered mental
status, confusion, and life-threatening seizures. Dry
mucous membranes and intense thirst are classic
signs of hypernatremia.
Q6. A nurse is reviewing the arterial blood gas
(ABG) results of a client who has been vomiting
continuously for 24 hours. The results are: pH 7.51,
PaCO2 44 mmHg, HCO3 34 mEq/L. The nurse should
interpret these findings as which of the following
acid-base imbalances?
A. Respiratory acidosis
