OCN Oncologic Emergencies Practice Questions (15 Free)
Published 2026-10-22 · Facts and text checked 2026-10-16 · Questions from our OCN study guide · Reviewed by Hana N., Quality Reviewer
These free OCN practice questions cover Oncologic Emergencies, part of V. Oncologic Emergencies on the exam. Recognizing and acting on DIC, SIADH, sepsis, tumor lysis, spinal cord compression and more. Each question comes from a practice test in our OCN study guide and shows the correct answer with an explanation. The full exam has 165 questions (145 scored, 20 unscored).
Recognizing and acting on DIC, SIADH, sepsis, tumor lysis, spinal cord compression and more. On the exam this is part of V. Oncologic Emergencies (16%). Open each answer to read the explanation.
Question 1Easy
A patient presents with facial puffiness, distended neck veins, and dyspnea that worsens when lying flat. What is the most likely underlying pathophysiology?
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Correct answer: A. Obstruction of blood flow through the superior vena cava
The symptoms describe superior vena cava syndrome, which results from obstruction of the SVC. Increased intracranial pressure does not cause neck vein distention. Cardiac tamponade presents with hypotension and muffled heart sounds. Pulmonary embolism presents with pleuritic chest pain and hypoxia.
From practice test 4 of our OCN study guide (question 67). Original question, not an official exam item.
Question 2Easy
Before administering rasburicase to a patient with Burkitt lymphoma, which laboratory screening test is essential to prevent a potential adverse reaction?
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Correct answer: C. Glucose-6-phosphate dehydrogenase (G6PD) level
Rasburicase can cause hemolytic anemia in patients with G6PD deficiency, so screening is mandatory. Other labs are important but do not screen for this specific risk.
From practice test 3 of our OCN study guide (question 75). Original question, not an official exam item.
Question 3Hard
A patient with laboratory tumor lysis syndrome (uric acid 9.5 mg/dL, potassium 6.2 mEq/L, phosphate 7.1 mg/dL, calcium 6.9 mg/dL) has a serum creatinine of 1.8 mg/dL (baseline 0.9 mg/dL) despite aggressive hydration and rasburicase. Which intervention is most urgently indicated?
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Correct answer: B. Hemodialysis
The patient has clinical tumor lysis syndrome with acute kidney injury (creatinine >1.5 times upper limit of normal) and multiple life-threatening electrolyte derangements (hyperkalemia, hyperphosphatemia, hyperuricemia). Hemodialysis is the definitive treatment because it rapidly clears potassium, phosphate, and uric acid.
From practice test 3 of our OCN study guide (question 120). Original question, not an official exam item.
Question 4Medium
Before administering rasburicase to a patient with tumor lysis syndrome, the nurse reviews the patient's history. Which finding would be a contraindication to this medication?
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Correct answer: A. Glucose-6-phosphate dehydrogenase deficiency
Rasburicase is contraindicated in patients with G6PD deficiency because it generates hydrogen peroxide as a byproduct, which can cause hemolytic anemia. Hyperuricemia is an indication for the drug.
From practice test 8 of our OCN study guide (question 162). Original question, not an official exam item.
Question 5Medium
A patient with tumor lysis syndrome has a serum potassium of 6.5 mEq/L. Which ECG finding is most indicative of severe hyperkalemia requiring immediate intervention?
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Correct answer: D. Widened QRS complex
While peaked T waves are an early sign, a widened QRS complex indicates more severe hyperkalemia and risk of ventricular arrhythmia, prompting urgent treatment.
From practice test 3 of our OCN study guide (question 15). Original question, not an official exam item.
Question 6Medium
A patient with tumor lysis syndrome has a potassium level of 6.8 mEq/L and ECG shows widened QRS. Which intervention should be administered immediately?
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Correct answer: C. Calcium gluconate 1 gram intravenously over 2 to 5 minutes
Intravenous calcium gluconate 1 gram given over 2-5 minutes stabilizes the cardiac membrane in life-threatening hyperkalemia. Higher doses or rapid administration increase risk; calcium chloride is also effective but more irritating.
From practice test 9 of our OCN study guide (question 126). Original question, not an official exam item.
Question 7Medium
A nurse is caring for a patient in the acute phase of cardiac tamponade before pericardiocentesis. Which nursing intervention is most important to augment preload?
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Correct answer: B. Maintain large-bore IV access and infuse intravenous fluids
In tamponade, preload augmentation with IV fluids helps maintain cardiac output despite reduced filling. Large-bore access allows rapid fluid administration.
From practice test 8 of our OCN study guide (question 34). Original question, not an official exam item.
Question 8Medium
Which of the following is the correct insulin and dextrose regimen for emergency management of hyperkalemia in tumor lysis syndrome?
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Correct answer: B. 10 units regular insulin intravenously with 50 mL of 50% dextrose
The standard regimen is 10 units of regular insulin IV followed by 50 mL of 50% dextrose to shift potassium intracellularly. Lower doses may be insufficient; NPH insulin is not used for acute shifts.
From practice test 9 of our OCN study guide (question 120). Original question, not an official exam item.
Question 9Easy
On physical examination of a patient with suspected superior vena cava syndrome, which finding is most consistent with the condition?
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Correct answer: D. Dilated collateral veins over the anterior chest and upper abdomen
Collateral venous circulation develops as the body reroutes blood from the blocked SVC through smaller veins, visible as dilated veins on the chest and upper abdomen.
From practice test 7 of our OCN study guide (question 67). Original question, not an official exam item.
Question 10Easy
A patient with cardiac tamponade is scheduled for pericardiocentesis. Which approach is recommended for needle insertion?
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Correct answer: D. Subxiphoid approach under ultrasound or fluoroscopic guidance
The subxiphoid approach is the standard for pericardiocentesis because it avoids the lung and major coronary vessels. Ultrasound or fluoroscopic guidance increases safety.
From practice test 8 of our OCN study guide (question 109). Original question, not an official exam item.
Question 11Easy
During the first 48-72 hours after initiation of chemotherapy for a patient at high risk for tumor lysis syndrome, how frequently should serum potassium, phosphate, calcium, uric acid, and creatinine be checked?
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Correct answer: C. Every 6-8 hours
The standard monitoring protocol for high-risk patients during the first 48-72 hours after therapy is every 6-8 hours. Increasing to every 4 hours is reserved for when values trend toward thresholds, not as the initial frequency.
From practice test 2 of our OCN study guide (question 48). Original question, not an official exam item.
Question 12Hard
A 55-year-old man with a history of Hodgkin lymphoma treated with mediastinal radiation therapy 12 years ago presents with chest pain and dyspnea. Echocardiogram shows a moderate pericardial effusion. What is the most likely etiology of his pericardial effusion?
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Correct answer: B. Radiation-induced pericarditis
Radiation-induced pericarditis can present years after mediastinal radiation, often within 5 to 15 years. The history of remote radiation makes this the most likely cause, whereas viral pericarditis, recurrence, or drug-induced causes are less consistent with the delayed presentation.
From practice test 7 of our OCN study guide (question 17). Original question, not an official exam item.
Question 13Easy
Which nursing assessment is most appropriate for monitoring the progression or resolution of superior vena cava syndrome?
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Correct answer: D. Neck circumference and bilateral arm circumference
Circumference measurements of neck and arms quantify edema related to venous congestion. Other assessments are less specific for SVCS.
From practice test 7 of our OCN study guide (question 2). Original question, not an official exam item.
Question 14Medium
A nurse draws blood for uric acid measurement 2 hours after administering rasburicase. Which action is critical for obtaining an accurate result?
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Correct answer: A. Place the specimen on ice immediately
Rasburicase continues to degrade uric acid in the tube at room temperature, causing falsely low readings. Placing the specimen on ice stops this degradation.
From practice test 3 of our OCN study guide (question 40). Original question, not an official exam item.
Question 15Medium
In a patient receiving aggressive intravenous hydration for tumor lysis syndrome (TLS) prophylaxis, which of the following best describes the appropriate use of a loop diuretic?
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Correct answer: A. Reserve a loop diuretic for patients who develop evidence of fluid overload.
Loop diuretics are not recommended for forced diuresis in euvolemic patients because they can worsen dehydration and concentrate solutes in the renal tubules. They should be used only when the patient demonstrates signs of fluid overload.
From practice test 6 of our OCN study guide (question 148). Original question, not an official exam item.
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