HESI Maternity 2 2026 Practice Exam
Comprehensive High-Stakes Practice
Examination.
SUB-TOPIC: Severe Preeclampsia & Magnesium Sulfate Toxicity (4 Questions)
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Question 1 (Multiple Choice)
A 28-year-old primigravida at 34 weeks gestation is admitted with severe preeclampsia. Her
blood pressure is 172/110 mmHg, urine protein is 3+, and she reports a severe headache and
visual disturbances. The physician orders a magnesium sulfate infusion. During the nurse's
assessment, the patient demonstrates clonus of 4+ beats. What is the nurse's priority action?
A) Decrease the magnesium sulfate infusion rate by half
B) Immediately stop the magnesium sulfate infusion and notify the provider
C) Continue the infusion and document the finding in the electronic health record
D) Administer a bolus dose of magnesium sulfate to achieve a higher therapeutic level
Answer: B) Immediately stop the magnesium sulfate infusion and notify the provider
[CORRECT]
RATIONALE: Clonus of 4+ beats (sustained rhythmic beating) is a sign of severe preeclampsia
and indicates central nervous system irritability. While magnesium sulfate is administered for
seizure prophylaxis, the presence of 4+ clonus in conjunction with severe hypertension
(172/110 mmHg), 3+ proteinuria, headache, and visual disturbances signals progression
toward eclampsia. The nurse must immediately discontinue the magnesium sulfate infusion
and notify the provider, as the patient may require delivery. The therapeutic serum
magnesium level for seizure prophylaxis is 4-7 mg/dL. Levels exceeding 8-10 mg/dL result in
the loss of deep tendon reflexes; levels exceeding 12 mg/dL cause respiratory depression and
cardiac arrest. The priority is provider notification for potential delivery planning, not
continuation or alteration of the tocolytic infusion
,Question 2 (Select-All-That-Apply)
A patient receiving magnesium sulfate for severe preeclampsia is being monitored for signs of
toxicity. Which findings indicate magnesium sulfate toxicity? (Select all that apply.)
A) Absent patellar deep tendon reflexes (DTRs)
B) Respiratory rate of 10 breaths per minute
C) Urine output of 45 mL/hour
D) Flushing and feeling of warmth
E) Decreased level of consciousness
F) Serum magnesium level of 9.2 mg/dL
Answer: A, B, E, F [CORRECT]
RATIONALE: Magnesium sulfate toxicity manifests in a predictable progression based on
serum levels:
• 4-7 mg/dL: Therapeutic range (seizure prophylaxis)
• 8-10 mg/dL: Loss of deep tendon reflexes (patellar reflexes disappear first)
• 10-12 mg/dL: Respiratory depression (respiratory rate <12 bpm indicates impending
respiratory arrest)
• >12 mg/dL: Respiratory arrest and cardiac arrest
• >15 mg/dL: Cardiac arrest
Absent patellar DTRs (Option A) occur at 8-10 mg/dL and are the earliest objective sign of
toxicity. A respiratory rate of 10 (Option B) indicates respiratory depression at the 10-12
mg/dL range. Decreased level of consciousness (Option E) and somnolence occur as
magnesium crosses the blood-brain barrier at toxic levels. A serum magnesium level of 9.2
mg/dL (Option F) exceeds the therapeutic ceiling of 7 mg/dL and indicates toxicity.
,Option C (urine output 45 mL/hr) is within normal limits (minimum 30 mL/hr required for safe
magnesium sulfate administration). Option D (flushing and warmth) is an expected, non-toxic
side effect of magnesium sulfate vasodilation.
Question 3 (Multiple Choice)
The nurse is assessing a patient receiving magnesium sulfate for severe preeclampsia. Which
assessment finding requires the nurse to withhold the next scheduled dose and immediately
notify the healthcare provider?
A) Patellar reflex rated as 2+ (brisk, normal)
B) Urine output of 25 mL in the past hour
C) Respiratory rate of 18 breaths per minute
D) Fetal heart rate baseline of 140 bpm with moderate variability
Answer: B) Urine output of 25 mL in the past hour [CORRECT]
RATIONALE: The safe administration of magnesium sulfate requires a minimum urine output
of 30 mL per hour. Magnesium is excreted entirely by the kidneys; impaired renal function
leads to accumulation and toxicity. A urine output of 25 mL/hour falls below the 30 mL/hour
safety threshold and indicates potential renal compromise or volume depletion. The nurse
must withhold the next dose and notify the provider immediately.
Option A (2+ patellar reflex) is normal and expected. Option C (respiratory rate 18) is within
normal limits (toxicity concerns arise at <12 bpm). Option D (FHR 140 with moderate
variability) represents a reassuring fetal status and is unrelated to maternal magnesium
sulfate toxicity assessment.
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, Question 4 (Multiple Choice)
A patient with severe preeclampsia is receiving a magnesium sulfate infusion at 2 g/hour. The
nurse performs a focused assessment and documents the following: blood pressure 158/96
mmHg, patellar reflexes absent, respiratory rate 11 breaths/minute, urine output 20 mL/hour,
and the patient is difficult to arouse. What is the nurse's immediate priority action?
A) Administer a loading dose of 4 g magnesium sulfate IV over 20 minutes
B) Prepare and administer calcium gluconate 1 g IV push slowly
C) Increase the maintenance infusion to 3 g/hour to deepen sedation
D) Position the patient supine and apply a non-rebreather mask at 10 L/min
Answer: B) Prepare and administer calcium gluconate 1 g IV push slowly [CORRECT]
RATIONALE: This patient presents with classic signs of severe magnesium sulfate toxicity:
absent patellar reflexes (indicates serum level >8 mg/dL), respiratory depression (RR 11,
approaching the critical <12 threshold), decreased urine output (<30 mL/hr), and altered
mental status (difficult to arouse). The antidote for magnesium sulfate toxicity is calcium
gluconate 1 g administered by slow IV push (over 3-5 minutes). Calcium acts as a direct
physiologic antagonist at the neuromuscular junction, reversing magnesium's depressant
effects on cardiac and respiratory function.
The nurse must keep calcium gluconate at the bedside whenever magnesium sulfate is
infusing. Option A would worsen toxicity. Option C is contraindicated. Option D addresses
oxygenation but does not treat the underlying magnesium toxicity; the patient requires the
specific antidote first.
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SUB-TOPIC: Non-Stress Test (NST) for Diabetic Patients (3 Questions)
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Comprehensive High-Stakes Practice
Examination.
SUB-TOPIC: Severe Preeclampsia & Magnesium Sulfate Toxicity (4 Questions)
--------------------------------------------------------------------------------
Question 1 (Multiple Choice)
A 28-year-old primigravida at 34 weeks gestation is admitted with severe preeclampsia. Her
blood pressure is 172/110 mmHg, urine protein is 3+, and she reports a severe headache and
visual disturbances. The physician orders a magnesium sulfate infusion. During the nurse's
assessment, the patient demonstrates clonus of 4+ beats. What is the nurse's priority action?
A) Decrease the magnesium sulfate infusion rate by half
B) Immediately stop the magnesium sulfate infusion and notify the provider
C) Continue the infusion and document the finding in the electronic health record
D) Administer a bolus dose of magnesium sulfate to achieve a higher therapeutic level
Answer: B) Immediately stop the magnesium sulfate infusion and notify the provider
[CORRECT]
RATIONALE: Clonus of 4+ beats (sustained rhythmic beating) is a sign of severe preeclampsia
and indicates central nervous system irritability. While magnesium sulfate is administered for
seizure prophylaxis, the presence of 4+ clonus in conjunction with severe hypertension
(172/110 mmHg), 3+ proteinuria, headache, and visual disturbances signals progression
toward eclampsia. The nurse must immediately discontinue the magnesium sulfate infusion
and notify the provider, as the patient may require delivery. The therapeutic serum
magnesium level for seizure prophylaxis is 4-7 mg/dL. Levels exceeding 8-10 mg/dL result in
the loss of deep tendon reflexes; levels exceeding 12 mg/dL cause respiratory depression and
cardiac arrest. The priority is provider notification for potential delivery planning, not
continuation or alteration of the tocolytic infusion
,Question 2 (Select-All-That-Apply)
A patient receiving magnesium sulfate for severe preeclampsia is being monitored for signs of
toxicity. Which findings indicate magnesium sulfate toxicity? (Select all that apply.)
A) Absent patellar deep tendon reflexes (DTRs)
B) Respiratory rate of 10 breaths per minute
C) Urine output of 45 mL/hour
D) Flushing and feeling of warmth
E) Decreased level of consciousness
F) Serum magnesium level of 9.2 mg/dL
Answer: A, B, E, F [CORRECT]
RATIONALE: Magnesium sulfate toxicity manifests in a predictable progression based on
serum levels:
• 4-7 mg/dL: Therapeutic range (seizure prophylaxis)
• 8-10 mg/dL: Loss of deep tendon reflexes (patellar reflexes disappear first)
• 10-12 mg/dL: Respiratory depression (respiratory rate <12 bpm indicates impending
respiratory arrest)
• >12 mg/dL: Respiratory arrest and cardiac arrest
• >15 mg/dL: Cardiac arrest
Absent patellar DTRs (Option A) occur at 8-10 mg/dL and are the earliest objective sign of
toxicity. A respiratory rate of 10 (Option B) indicates respiratory depression at the 10-12
mg/dL range. Decreased level of consciousness (Option E) and somnolence occur as
magnesium crosses the blood-brain barrier at toxic levels. A serum magnesium level of 9.2
mg/dL (Option F) exceeds the therapeutic ceiling of 7 mg/dL and indicates toxicity.
,Option C (urine output 45 mL/hr) is within normal limits (minimum 30 mL/hr required for safe
magnesium sulfate administration). Option D (flushing and warmth) is an expected, non-toxic
side effect of magnesium sulfate vasodilation.
Question 3 (Multiple Choice)
The nurse is assessing a patient receiving magnesium sulfate for severe preeclampsia. Which
assessment finding requires the nurse to withhold the next scheduled dose and immediately
notify the healthcare provider?
A) Patellar reflex rated as 2+ (brisk, normal)
B) Urine output of 25 mL in the past hour
C) Respiratory rate of 18 breaths per minute
D) Fetal heart rate baseline of 140 bpm with moderate variability
Answer: B) Urine output of 25 mL in the past hour [CORRECT]
RATIONALE: The safe administration of magnesium sulfate requires a minimum urine output
of 30 mL per hour. Magnesium is excreted entirely by the kidneys; impaired renal function
leads to accumulation and toxicity. A urine output of 25 mL/hour falls below the 30 mL/hour
safety threshold and indicates potential renal compromise or volume depletion. The nurse
must withhold the next dose and notify the provider immediately.
Option A (2+ patellar reflex) is normal and expected. Option C (respiratory rate 18) is within
normal limits (toxicity concerns arise at <12 bpm). Option D (FHR 140 with moderate
variability) represents a reassuring fetal status and is unrelated to maternal magnesium
sulfate toxicity assessment.
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, Question 4 (Multiple Choice)
A patient with severe preeclampsia is receiving a magnesium sulfate infusion at 2 g/hour. The
nurse performs a focused assessment and documents the following: blood pressure 158/96
mmHg, patellar reflexes absent, respiratory rate 11 breaths/minute, urine output 20 mL/hour,
and the patient is difficult to arouse. What is the nurse's immediate priority action?
A) Administer a loading dose of 4 g magnesium sulfate IV over 20 minutes
B) Prepare and administer calcium gluconate 1 g IV push slowly
C) Increase the maintenance infusion to 3 g/hour to deepen sedation
D) Position the patient supine and apply a non-rebreather mask at 10 L/min
Answer: B) Prepare and administer calcium gluconate 1 g IV push slowly [CORRECT]
RATIONALE: This patient presents with classic signs of severe magnesium sulfate toxicity:
absent patellar reflexes (indicates serum level >8 mg/dL), respiratory depression (RR 11,
approaching the critical <12 threshold), decreased urine output (<30 mL/hr), and altered
mental status (difficult to arouse). The antidote for magnesium sulfate toxicity is calcium
gluconate 1 g administered by slow IV push (over 3-5 minutes). Calcium acts as a direct
physiologic antagonist at the neuromuscular junction, reversing magnesium's depressant
effects on cardiac and respiratory function.
The nurse must keep calcium gluconate at the bedside whenever magnesium sulfate is
infusing. Option A would worsen toxicity. Option C is contraindicated. Option D addresses
oxygenation but does not treat the underlying magnesium toxicity; the patient requires the
specific antidote first.
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SUB-TOPIC: Non-Stress Test (NST) for Diabetic Patients (3 Questions)
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