, BSN HESI 266 Med-Surg Final Exam:
High-Yield Questions, Answers, &
Rationales 2026/2027 Update
Question 1: Cardiovascular & Acute Coronary Syndrome
A client is admitted to the emergency department reporting
substernal chest pressure that began 2 hours ago. The 12-lead
electrocardiogram (ECG) reveals ST-segment elevation in leads
V1 through V4. The nurse recognizes that these findings
indicate which underlying condition?
A. Lateral wall ischemia.
B. Inferior wall ST-elevation myocardial infarction
(STEMI).
C. Anterior wall ST-elevation myocardial infarction
(STEMI).
D. Right ventricular hypertrophy.
Correct Answer: C. Anterior wall ST-elevation myocardial
infarction (STEMI).
Explanation: Leads V1 through V4 view the anterior wall of
the left ventricle, which is supplied by the left anterior
descending (LAD) artery. ST-elevation in these leads indicates
an acute anterior wall STEMI, often referred to as a "widow-
maker" heart attack, carrying a high risk for cardiogenic shock
and heart failure.
Question 2: Respiratory & Chest Tube Management
,While assessing a client with a chest tube connected to a dry
suction water-seal system, the nurse notes that the water level in
the water-seal chamber fluctuates with the client's breathing
(tidaling). What is the correct interpretation of this finding?
A. There is a large air leak requiring immediate clamp
replacement.
B. The system is functioning normally and the chest tube is
patent.
C. The lung has completely re-expanded and the tube
should be removed.
D. The suction control regulator is set too high.
Correct Answer: B. The system is functioning normally and
the chest tube is patent.
Explanation: Tidaling (the rise and fall of water in the water-
seal chamber synchronous with inspiration and expiration)
indicates normal functioning and patency of the chest tube
system. Absence of tidaling can indicate lung re-expansion or
tubing obstruction/kinking.
Question 3: Endocrine & Diabetic Ketoacidosis (DKA)
Management
A client is admitted to the ICU with diabetic ketoacidosis
(DKA). Initial blood glucose is 620 mg/dL, pH is 7.12, serum
bicarbonate is 11 mEq/L, and serum potassium is 3.4 mEq/L.
Which order should the nurse implement first?
A. Administer regular insulin IV push immediately.
B. Initiate potassium replacement before starting insulin.
C. Administer 0.9% Normal Saline IV bolus.
, D. Administer sodium bicarbonate IV push.
Correct Answer: B. Initiate potassium replacement before
starting insulin.
Explanation: Although insulin is critical in DKA, administering
insulin when serum potassium is below 3.3 mEq/L can drive
potassium rapidly back into cells, precipitating life-threatening
cardiac dysrhythmias. Potassium must be corrected to $\ge 3.3$
mEq/L before insulin infusion is started.
Question 4: Renal & Peritoneal Dialysis Complications
A client receiving continuous ambulatory peritoneal dialysis
(CAPD) calls the clinic reporting that the drained effluent is
cloudy and turbid, accompanied by a low-grade fever and
diffuse abdominal tenderness. What is the priority nursing
action?
A. Reassure the client that this is a normal finding after
long dwell times.
B. Warm the next dialysate bag to a higher temperature.
C. Instruct the client to save a sample of the effluent, notify
the nephrology provider, and prepare for culture and
sensitivity testing.
D. Flush the peritoneal catheter forcefully with heparinized
saline.
Correct Answer: C. Instruct the client to save a sample of
the effluent, notify the nephrology provider, and prepare for
culture and sensitivity testing.
High-Yield Questions, Answers, &
Rationales 2026/2027 Update
Question 1: Cardiovascular & Acute Coronary Syndrome
A client is admitted to the emergency department reporting
substernal chest pressure that began 2 hours ago. The 12-lead
electrocardiogram (ECG) reveals ST-segment elevation in leads
V1 through V4. The nurse recognizes that these findings
indicate which underlying condition?
A. Lateral wall ischemia.
B. Inferior wall ST-elevation myocardial infarction
(STEMI).
C. Anterior wall ST-elevation myocardial infarction
(STEMI).
D. Right ventricular hypertrophy.
Correct Answer: C. Anterior wall ST-elevation myocardial
infarction (STEMI).
Explanation: Leads V1 through V4 view the anterior wall of
the left ventricle, which is supplied by the left anterior
descending (LAD) artery. ST-elevation in these leads indicates
an acute anterior wall STEMI, often referred to as a "widow-
maker" heart attack, carrying a high risk for cardiogenic shock
and heart failure.
Question 2: Respiratory & Chest Tube Management
,While assessing a client with a chest tube connected to a dry
suction water-seal system, the nurse notes that the water level in
the water-seal chamber fluctuates with the client's breathing
(tidaling). What is the correct interpretation of this finding?
A. There is a large air leak requiring immediate clamp
replacement.
B. The system is functioning normally and the chest tube is
patent.
C. The lung has completely re-expanded and the tube
should be removed.
D. The suction control regulator is set too high.
Correct Answer: B. The system is functioning normally and
the chest tube is patent.
Explanation: Tidaling (the rise and fall of water in the water-
seal chamber synchronous with inspiration and expiration)
indicates normal functioning and patency of the chest tube
system. Absence of tidaling can indicate lung re-expansion or
tubing obstruction/kinking.
Question 3: Endocrine & Diabetic Ketoacidosis (DKA)
Management
A client is admitted to the ICU with diabetic ketoacidosis
(DKA). Initial blood glucose is 620 mg/dL, pH is 7.12, serum
bicarbonate is 11 mEq/L, and serum potassium is 3.4 mEq/L.
Which order should the nurse implement first?
A. Administer regular insulin IV push immediately.
B. Initiate potassium replacement before starting insulin.
C. Administer 0.9% Normal Saline IV bolus.
, D. Administer sodium bicarbonate IV push.
Correct Answer: B. Initiate potassium replacement before
starting insulin.
Explanation: Although insulin is critical in DKA, administering
insulin when serum potassium is below 3.3 mEq/L can drive
potassium rapidly back into cells, precipitating life-threatening
cardiac dysrhythmias. Potassium must be corrected to $\ge 3.3$
mEq/L before insulin infusion is started.
Question 4: Renal & Peritoneal Dialysis Complications
A client receiving continuous ambulatory peritoneal dialysis
(CAPD) calls the clinic reporting that the drained effluent is
cloudy and turbid, accompanied by a low-grade fever and
diffuse abdominal tenderness. What is the priority nursing
action?
A. Reassure the client that this is a normal finding after
long dwell times.
B. Warm the next dialysate bag to a higher temperature.
C. Instruct the client to save a sample of the effluent, notify
the nephrology provider, and prepare for culture and
sensitivity testing.
D. Flush the peritoneal catheter forcefully with heparinized
saline.
Correct Answer: C. Instruct the client to save a sample of
the effluent, notify the nephrology provider, and prepare for
culture and sensitivity testing.
