1
HESI Specialty Exam Prep: Fluid &
Electrolyte Management in Med-Surg
Nursing
Table of Contents
Subtopic 1: Sodium Imbalances (Hyponatremia & Hypernatremia).................2
Subtopic 2: Potassium Imbalances (Hypokalemia & Hyperkalemia)..............11
Subtopic 3: Calcium and Phosphate Imbalances...........................................20
Subtopic 4: Magnesium Imbalances (Hypomagnesemia & Hypermagnesemia)
.......................................................................................................................29
Subtopic 5: Electrolyte Imbalances in Endocrine Disorders...........................38
Subtopic 6: Electrolyte Management in Clients with Cardiac Conditions.......46
Subtopic 7: Fluid & Electrolyte Imbalances Related to Neurological Function
.......................................................................................................................55
Subtopic 8: Fluid & Electrolyte Considerations in Endocrine Disorders..........64
Subtopic 9: Fluid and Electrolyte Imbalances in Cardiac and Renal Disorders
.......................................................................................................................72
Subtopic 10: Geriatric Considerations in Fluid & Electrolyte Management....80
, 2
Subtopic 1: Sodium Imbalances
(Hyponatremia & Hypernatremia)
Question 1:
A nurse is assessing a client with a serum sodium level of 128 mEq/L. Which
of the following symptoms is the most concerning and requires immediate
intervention?
A. Dry mucous membranes
B. Seizure activity
C. Muscle cramps
D. Fatigue
Correct Answer: B. Seizure activity
Rationale: Seizures indicate severe hyponatremia affecting cerebral function.
Sodium plays a key role in nerve transmission, and dangerously low levels
can cause cerebral edema and increased intracranial pressure. This is a
medical emergency.
Question 2:
Which IV solution is most appropriate for a client with symptomatic
hyponatremia and neurological changes?
A. 0.45% Normal Saline
B. 3% Hypertonic Saline
C. Lactated Ringer’s
D. Dextrose 5% in Water
Correct Answer: B. 3% Hypertonic Saline
, 3
Rationale: Hypertonic saline (3%) is used cautiously to treat severe
hyponatremia with neurological symptoms. It pulls fluid out of brain cells and
reduces cerebral edema.
Question 3:
Which patient is at greatest risk for developing hypernatremia?
A. A patient receiving continuous tube feeding without water flushes
B. A patient on diuretics for heart failure
C. A patient who had diarrhea for 2 days
D. A patient with diabetes insipidus
Correct Answer: D. A patient with diabetes insipidus
Rationale: Diabetes insipidus causes massive fluid loss without sodium loss,
leading to hypernatremia. These patients excrete large volumes of dilute
urine.
Question 4:
Which nursing intervention is priority in managing a patient with a sodium
level of 150 mEq/L?
A. Administering salt tablets
B. Encouraging fluid restriction
C. Providing free water orally or via NG tube
D. Monitoring for Chvostek's sign
Correct Answer: C. Providing free water orally or via NG tube
Rationale: Free water administration helps correct mild hypernatremia due to
dehydration. The goal is to gradually restore serum sodium.
, 4
Question 5:
The nurse is educating a patient on dietary modifications for hyponatremia.
Which food should be included?
A. Banana
B. Broccoli
C. Canned soup
D. Apple
Correct Answer: C. Canned soup
Rationale: Canned soups are typically high in sodium and can help increase
sodium intake in patients with hyponatremia due to dietary deficiency.
Question 6:
A patient presents with dry skin, flushed face, restlessness, and a sodium
level of 154 mEq/L. What is the most likely cause?
A. Adrenal insufficiency
B. Dehydration from water loss
C. Overuse of potassium supplements
D. Fluid overload
Correct Answer: B. Dehydration from water loss
Rationale: The symptoms and elevated sodium point to water loss without
adequate fluid replacement, a common cause of hypernatremia.
Question 7:
HESI Specialty Exam Prep: Fluid &
Electrolyte Management in Med-Surg
Nursing
Table of Contents
Subtopic 1: Sodium Imbalances (Hyponatremia & Hypernatremia).................2
Subtopic 2: Potassium Imbalances (Hypokalemia & Hyperkalemia)..............11
Subtopic 3: Calcium and Phosphate Imbalances...........................................20
Subtopic 4: Magnesium Imbalances (Hypomagnesemia & Hypermagnesemia)
.......................................................................................................................29
Subtopic 5: Electrolyte Imbalances in Endocrine Disorders...........................38
Subtopic 6: Electrolyte Management in Clients with Cardiac Conditions.......46
Subtopic 7: Fluid & Electrolyte Imbalances Related to Neurological Function
.......................................................................................................................55
Subtopic 8: Fluid & Electrolyte Considerations in Endocrine Disorders..........64
Subtopic 9: Fluid and Electrolyte Imbalances in Cardiac and Renal Disorders
.......................................................................................................................72
Subtopic 10: Geriatric Considerations in Fluid & Electrolyte Management....80
, 2
Subtopic 1: Sodium Imbalances
(Hyponatremia & Hypernatremia)
Question 1:
A nurse is assessing a client with a serum sodium level of 128 mEq/L. Which
of the following symptoms is the most concerning and requires immediate
intervention?
A. Dry mucous membranes
B. Seizure activity
C. Muscle cramps
D. Fatigue
Correct Answer: B. Seizure activity
Rationale: Seizures indicate severe hyponatremia affecting cerebral function.
Sodium plays a key role in nerve transmission, and dangerously low levels
can cause cerebral edema and increased intracranial pressure. This is a
medical emergency.
Question 2:
Which IV solution is most appropriate for a client with symptomatic
hyponatremia and neurological changes?
A. 0.45% Normal Saline
B. 3% Hypertonic Saline
C. Lactated Ringer’s
D. Dextrose 5% in Water
Correct Answer: B. 3% Hypertonic Saline
, 3
Rationale: Hypertonic saline (3%) is used cautiously to treat severe
hyponatremia with neurological symptoms. It pulls fluid out of brain cells and
reduces cerebral edema.
Question 3:
Which patient is at greatest risk for developing hypernatremia?
A. A patient receiving continuous tube feeding without water flushes
B. A patient on diuretics for heart failure
C. A patient who had diarrhea for 2 days
D. A patient with diabetes insipidus
Correct Answer: D. A patient with diabetes insipidus
Rationale: Diabetes insipidus causes massive fluid loss without sodium loss,
leading to hypernatremia. These patients excrete large volumes of dilute
urine.
Question 4:
Which nursing intervention is priority in managing a patient with a sodium
level of 150 mEq/L?
A. Administering salt tablets
B. Encouraging fluid restriction
C. Providing free water orally or via NG tube
D. Monitoring for Chvostek's sign
Correct Answer: C. Providing free water orally or via NG tube
Rationale: Free water administration helps correct mild hypernatremia due to
dehydration. The goal is to gradually restore serum sodium.
, 4
Question 5:
The nurse is educating a patient on dietary modifications for hyponatremia.
Which food should be included?
A. Banana
B. Broccoli
C. Canned soup
D. Apple
Correct Answer: C. Canned soup
Rationale: Canned soups are typically high in sodium and can help increase
sodium intake in patients with hyponatremia due to dietary deficiency.
Question 6:
A patient presents with dry skin, flushed face, restlessness, and a sodium
level of 154 mEq/L. What is the most likely cause?
A. Adrenal insufficiency
B. Dehydration from water loss
C. Overuse of potassium supplements
D. Fluid overload
Correct Answer: B. Dehydration from water loss
Rationale: The symptoms and elevated sodium point to water loss without
adequate fluid replacement, a common cause of hypernatremia.
Question 7:
