The Ultimate and Complete BSN HESI 266 Exam Study
Guide 2025, Covering Comprehensive Nursing Concepts,
Advanced Medical-Surgical Nursing, Pharmacology, Patient
Care Prioritization, Clinical Judgment and Critical
Thinking, Dosage Calculations, Evidence-Based Practice,
Safety and Infection Control, Leadership and Management
in Nursing, Practice Questions with Verified Answers and
Detailed Rationales, Real Exam Scenarios, Step-by-Step
Strategies, and Proven Methods to Successfully Pass the
HESI 266 Exam on the First Attempt with High Scores
Question 1: A nurse is preparing to administer a subcutaneous injection of heparin. Which
action should the nurse take to minimize tissue irritation?
A. Massage the injection site vigorously after administration
B. Use a 22-gauge needle for rapid medication delivery
C. Pinch the skin and inject at a 45- to 90-degree angle
D. Aspirate before injecting to confirm placement
CORRECT ANSWER: C. Pinch the skin and inject at a 45- to 90-degree angle
RATIONALE: For subcutaneous heparin administration, pinching the skin and injecting at a 45-
to 90-degree angle ensures the medication is deposited into the subcutaneous tissue, reducing
the risk of intramuscular injection and subsequent tissue irritation or hematoma. Massaging the
site is contraindicated as it can increase bruising. Aspiration is not recommended for
subcutaneous heparin injections per current guidelines. A 22-gauge needle is too large; a 25- to
27-gauge needle is preferred.
Question 2: Which finding in a postoperative client should the nurse report immediately to
the healthcare provider?
A. Temperature of 99.5°F (37.5°C)
B. Urine output of 25 mL/hr for two consecutive hours
C. Mild incisional pain rated 3/10
D. Serous drainage on the dressing
CORRECT ANSWER: B. Urine output of 25 mL/hr for two consecutive hours
RATIONALE: Urine output less than 30 mL/hr in an adult may indicate inadequate renal
perfusion, hypovolemia, or acute kidney injury, which requires immediate intervention. A
temperature of 99.5°F is within normal postoperative limits. Mild pain and serous drainage are
expected findings. Oliguria is a critical sign that must be reported promptly to prevent
complications.
,Question 3: The nurse is teaching a client with type 2 diabetes about foot care. Which
statement by the client indicates understanding?
A. "I will soak my feet in hot water daily to keep them clean."
B. "I will wear cotton socks and well-fitting shoes."
C. "I will cut my toenails in a rounded shape to prevent ingrown nails."
D. "I will apply lotion between my toes to prevent dryness."
CORRECT ANSWER: B. I will wear cotton socks and well-fitting shoes.
RATIONALE: Clients with diabetes are at high risk for foot ulcers and infections. Cotton socks
absorb moisture, and well-fitting shoes prevent pressure injuries. Soaking feet in hot water can
cause burns due to neuropathy. Toenails should be cut straight across, not rounded, to avoid
ingrown nails. Lotion should not be applied between toes as moisture promotes fungal growth.
Question 4: A client with heart failure is prescribed furosemide 40 mg orally daily. Which
laboratory value requires monitoring?
A. Serum potassium
B. Serum calcium
C. Blood urea nitrogen
D. Hemoglobin A1c
CORRECT ANSWER: A. Serum potassium
RATIONALE: Furosemide is a loop diuretic that promotes excretion of potassium, increasing the
risk of hypokalemia, which can cause cardiac dysrhythmias. Serum potassium must be
monitored regularly. While BUN may be affected by diuretic therapy, potassium imbalance is
the most immediate concern. Calcium and HbA1c are not directly impacted by furosemide.
Question 5: Which action by the nurse demonstrates adherence to the principle of
beneficence?
A. Respecting a client's refusal of blood transfusion
B. Administering pain medication before a painful procedure
C. Reporting a colleague's medication error
D. Maintaining client confidentiality in documentation
CORRECT ANSWER: B. Administering pain medication before a painful procedure
RATIONALE: Beneficence refers to acting in the best interest of the client and promoting well-
being. Administering analgesia prophylactically to prevent pain aligns with this ethical principle.
Respecting refusal relates to autonomy, reporting errors to veracity/justice, and confidentiality
to privacy.
,Question 6: A nurse is caring for a client with chronic obstructive pulmonary disease (COPD).
Which oxygen delivery method is most appropriate?
A. Non-rebreather mask at 15 L/min
B. Nasal cannula at 1-2 L/min
C. Simple face mask at 8 L/min
D. Venturi mask at 24% FiO₂
CORRECT ANSWER: B. Nasal cannula at 1-2 L/min
RATIONALE: Clients with COPD often rely on hypoxic drive for ventilation. High-flow oxygen can
suppress this drive, leading to respiratory depression. Low-flow oxygen via nasal cannula (1-2
L/min) provides controlled supplementation. Venturi masks deliver precise FiO₂ but are
typically used when higher, controlled concentrations are needed; however, starting low is
safest. Non-rebreather and simple masks deliver high concentrations and are contraindicated
initially.
Question 7: The nurse is assessing a client with suspected deep vein thrombosis (DVT). Which
finding is most indicative of DVT?
A. Bilateral pedal edema
B. Unilateral calf pain and swelling
C. Cool, pale extremity
D. Diminished peripheral pulses
CORRECT ANSWER: B. Unilateral calf pain and swelling
RATIONALE: Unilateral calf pain, swelling, warmth, and redness are classic signs of DVT.
Bilateral edema suggests systemic causes like heart failure. Cool, pale extremity and diminished
pulses indicate arterial insufficiency, not venous thrombosis.
Question 8: Which intervention should the nurse prioritize for a client experiencing an acute
asthma attack?
A. Administer albuterol via nebulizer
B. Obtain a peak flow measurement
C. Position the client in high Fowler's position
D. Apply oxygen via nasal cannula
CORRECT ANSWER: A. Administer albuterol via nebulizer
RATIONALE: During an acute asthma attack, bronchodilation is the priority to reverse airway
obstruction. Albuterol, a short-acting beta-agonist, is first-line treatment. While positioning and
oxygen are supportive, they do not address the underlying bronchospasm. Peak flow
measurement is useful for monitoring but not during acute distress.
, Question 9: A client is prescribed warfarin. Which food should the nurse instruct the client to
consume consistently?
A. Leafy green vegetables
B. Citrus fruits
C. Dairy products
D. Whole grains
CORRECT ANSWER: A. Leafy green vegetables
RATIONALE: Leafy green vegetables are high in vitamin K, which antagonizes warfarin.
Consistency in vitamin K intake is crucial to maintain stable INR levels. Sudden increases or
decreases can alter anticoagulation control. Citrus fruits, dairy, and whole grains do not
significantly affect warfarin therapy.
Question 10: The nurse is preparing to insert an indwelling urinary catheter in a male client.
Which action reduces the risk of catheter-associated urinary tract infection (CAUTI)?
A. Use sterile technique during insertion
B. Inflate the balloon before insertion
C. Cleanse the meatus with soap and water only
D. Secure the catheter to the lower abdomen
CORRECT ANSWER: A. Use sterile technique during insertion
RATIONALE: Sterile technique during catheter insertion is essential to prevent introduction of
pathogens and reduce CAUTI risk. The balloon should be inflated only after the catheter is fully
inserted into the bladder. Cleansing should be done with an antiseptic solution, not soap and
water. Securing the catheter prevents urethral traction but does not directly prevent infection.
Question 11: Which assessment finding in a client with preeclampsia requires immediate
intervention?
A. Blood pressure 150/95 mmHg
B. 2+ proteinuria
C. Severe headache unrelieved by medication
D. 1+ edema in lower extremities
CORRECT ANSWER: C. Severe headache unrelieved by medication
RATIONALE: A severe, persistent headache in preeclampsia may indicate cerebral edema or
impending eclampsia, requiring urgent treatment with magnesium sulfate and possible
delivery. Elevated BP and proteinuria are diagnostic criteria but not immediately life-
threatening. Mild edema is common in pregnancy.
Guide 2025, Covering Comprehensive Nursing Concepts,
Advanced Medical-Surgical Nursing, Pharmacology, Patient
Care Prioritization, Clinical Judgment and Critical
Thinking, Dosage Calculations, Evidence-Based Practice,
Safety and Infection Control, Leadership and Management
in Nursing, Practice Questions with Verified Answers and
Detailed Rationales, Real Exam Scenarios, Step-by-Step
Strategies, and Proven Methods to Successfully Pass the
HESI 266 Exam on the First Attempt with High Scores
Question 1: A nurse is preparing to administer a subcutaneous injection of heparin. Which
action should the nurse take to minimize tissue irritation?
A. Massage the injection site vigorously after administration
B. Use a 22-gauge needle for rapid medication delivery
C. Pinch the skin and inject at a 45- to 90-degree angle
D. Aspirate before injecting to confirm placement
CORRECT ANSWER: C. Pinch the skin and inject at a 45- to 90-degree angle
RATIONALE: For subcutaneous heparin administration, pinching the skin and injecting at a 45-
to 90-degree angle ensures the medication is deposited into the subcutaneous tissue, reducing
the risk of intramuscular injection and subsequent tissue irritation or hematoma. Massaging the
site is contraindicated as it can increase bruising. Aspiration is not recommended for
subcutaneous heparin injections per current guidelines. A 22-gauge needle is too large; a 25- to
27-gauge needle is preferred.
Question 2: Which finding in a postoperative client should the nurse report immediately to
the healthcare provider?
A. Temperature of 99.5°F (37.5°C)
B. Urine output of 25 mL/hr for two consecutive hours
C. Mild incisional pain rated 3/10
D. Serous drainage on the dressing
CORRECT ANSWER: B. Urine output of 25 mL/hr for two consecutive hours
RATIONALE: Urine output less than 30 mL/hr in an adult may indicate inadequate renal
perfusion, hypovolemia, or acute kidney injury, which requires immediate intervention. A
temperature of 99.5°F is within normal postoperative limits. Mild pain and serous drainage are
expected findings. Oliguria is a critical sign that must be reported promptly to prevent
complications.
,Question 3: The nurse is teaching a client with type 2 diabetes about foot care. Which
statement by the client indicates understanding?
A. "I will soak my feet in hot water daily to keep them clean."
B. "I will wear cotton socks and well-fitting shoes."
C. "I will cut my toenails in a rounded shape to prevent ingrown nails."
D. "I will apply lotion between my toes to prevent dryness."
CORRECT ANSWER: B. I will wear cotton socks and well-fitting shoes.
RATIONALE: Clients with diabetes are at high risk for foot ulcers and infections. Cotton socks
absorb moisture, and well-fitting shoes prevent pressure injuries. Soaking feet in hot water can
cause burns due to neuropathy. Toenails should be cut straight across, not rounded, to avoid
ingrown nails. Lotion should not be applied between toes as moisture promotes fungal growth.
Question 4: A client with heart failure is prescribed furosemide 40 mg orally daily. Which
laboratory value requires monitoring?
A. Serum potassium
B. Serum calcium
C. Blood urea nitrogen
D. Hemoglobin A1c
CORRECT ANSWER: A. Serum potassium
RATIONALE: Furosemide is a loop diuretic that promotes excretion of potassium, increasing the
risk of hypokalemia, which can cause cardiac dysrhythmias. Serum potassium must be
monitored regularly. While BUN may be affected by diuretic therapy, potassium imbalance is
the most immediate concern. Calcium and HbA1c are not directly impacted by furosemide.
Question 5: Which action by the nurse demonstrates adherence to the principle of
beneficence?
A. Respecting a client's refusal of blood transfusion
B. Administering pain medication before a painful procedure
C. Reporting a colleague's medication error
D. Maintaining client confidentiality in documentation
CORRECT ANSWER: B. Administering pain medication before a painful procedure
RATIONALE: Beneficence refers to acting in the best interest of the client and promoting well-
being. Administering analgesia prophylactically to prevent pain aligns with this ethical principle.
Respecting refusal relates to autonomy, reporting errors to veracity/justice, and confidentiality
to privacy.
,Question 6: A nurse is caring for a client with chronic obstructive pulmonary disease (COPD).
Which oxygen delivery method is most appropriate?
A. Non-rebreather mask at 15 L/min
B. Nasal cannula at 1-2 L/min
C. Simple face mask at 8 L/min
D. Venturi mask at 24% FiO₂
CORRECT ANSWER: B. Nasal cannula at 1-2 L/min
RATIONALE: Clients with COPD often rely on hypoxic drive for ventilation. High-flow oxygen can
suppress this drive, leading to respiratory depression. Low-flow oxygen via nasal cannula (1-2
L/min) provides controlled supplementation. Venturi masks deliver precise FiO₂ but are
typically used when higher, controlled concentrations are needed; however, starting low is
safest. Non-rebreather and simple masks deliver high concentrations and are contraindicated
initially.
Question 7: The nurse is assessing a client with suspected deep vein thrombosis (DVT). Which
finding is most indicative of DVT?
A. Bilateral pedal edema
B. Unilateral calf pain and swelling
C. Cool, pale extremity
D. Diminished peripheral pulses
CORRECT ANSWER: B. Unilateral calf pain and swelling
RATIONALE: Unilateral calf pain, swelling, warmth, and redness are classic signs of DVT.
Bilateral edema suggests systemic causes like heart failure. Cool, pale extremity and diminished
pulses indicate arterial insufficiency, not venous thrombosis.
Question 8: Which intervention should the nurse prioritize for a client experiencing an acute
asthma attack?
A. Administer albuterol via nebulizer
B. Obtain a peak flow measurement
C. Position the client in high Fowler's position
D. Apply oxygen via nasal cannula
CORRECT ANSWER: A. Administer albuterol via nebulizer
RATIONALE: During an acute asthma attack, bronchodilation is the priority to reverse airway
obstruction. Albuterol, a short-acting beta-agonist, is first-line treatment. While positioning and
oxygen are supportive, they do not address the underlying bronchospasm. Peak flow
measurement is useful for monitoring but not during acute distress.
, Question 9: A client is prescribed warfarin. Which food should the nurse instruct the client to
consume consistently?
A. Leafy green vegetables
B. Citrus fruits
C. Dairy products
D. Whole grains
CORRECT ANSWER: A. Leafy green vegetables
RATIONALE: Leafy green vegetables are high in vitamin K, which antagonizes warfarin.
Consistency in vitamin K intake is crucial to maintain stable INR levels. Sudden increases or
decreases can alter anticoagulation control. Citrus fruits, dairy, and whole grains do not
significantly affect warfarin therapy.
Question 10: The nurse is preparing to insert an indwelling urinary catheter in a male client.
Which action reduces the risk of catheter-associated urinary tract infection (CAUTI)?
A. Use sterile technique during insertion
B. Inflate the balloon before insertion
C. Cleanse the meatus with soap and water only
D. Secure the catheter to the lower abdomen
CORRECT ANSWER: A. Use sterile technique during insertion
RATIONALE: Sterile technique during catheter insertion is essential to prevent introduction of
pathogens and reduce CAUTI risk. The balloon should be inflated only after the catheter is fully
inserted into the bladder. Cleansing should be done with an antiseptic solution, not soap and
water. Securing the catheter prevents urethral traction but does not directly prevent infection.
Question 11: Which assessment finding in a client with preeclampsia requires immediate
intervention?
A. Blood pressure 150/95 mmHg
B. 2+ proteinuria
C. Severe headache unrelieved by medication
D. 1+ edema in lower extremities
CORRECT ANSWER: C. Severe headache unrelieved by medication
RATIONALE: A severe, persistent headache in preeclampsia may indicate cerebral edema or
impending eclampsia, requiring urgent treatment with magnesium sulfate and possible
delivery. Elevated BP and proteinuria are diagnostic criteria but not immediately life-
threatening. Mild edema is common in pregnancy.
