OCN exam prep — 2,755 oncology nursing questions with rationales

C is correct.Transdermal fentanyl first forms a drug depot in the skin before it is absorbed, so serum concentrations rise slowly and typically reach therapeutic levels 12 to 24 hours after the first patch is applied, then stay fairly constant through the 72-hour wear period. Because of this delay, the previous opioid must be bridged: a patient taking a 12-hour extended-release opioid takes the last dose when the patch goes on, and a patient using immediate-release doses continues them around the clock for about 12 hours, with breakthrough doses available throughout. In 30 to 60 minutes is wrong because that timing reflects the rapid onset of intravenous or transmucosal fentanyl; the patch is unsuitable for acute or rapidly changing pain. In 2 to 4 hours is wrong because absorption through the skin has barely begun at that point. In 7 to 10 days is wrong because adequate levels are reached within the first day, although the dose should not be increased until at least 3 days after the first application. Teaching includes avoiding heating pads, hot tubs, and fever-related heat over the patch, which speed absorption and raise overdose risk, and knowing that drug effects persist for many hours after removal.

A is correct.Current ONS chemotherapy administration standards direct the nurse to confirm a brisk blood return before giving a vesicant and then every 2 to 5 mL during a peripheral IV push, while also watching the site for swelling, redness, or pain. Frequent checks matter because a peripheral vein can be fragile, and a vesicant such as doxorubicin can cause blistering, tissue necrosis, and loss of function if even a small volume leaks. Checking every 10 to 15 mL is wrong because that interval would let too much drug escape before the problem is detected. Checking every 20 to 25 mL is even less safe and matches no accepted standard. Checking only before the push is wrong because a blood return confirmed at the start does not guarantee the catheter stays in the vein; its position can change as the patient moves or the vein wall weakens. The nurse should give the drug through the side port of a freely flowing compatible solution, use a newly placed catheter in the forearm rather than the hand, wrist, or antecubital area, stop immediately if blood return is lost or the patient reports burning, and avoid continuous vesicant infusions through peripheral lines.

D is correct.Under the Cairo-Bishop definition, laboratory tumor lysis syndrome requires two or more abnormal values occurring from 3 days before to 7 days after starting therapy, with absolute thresholds of uric acid 8 mg/dL or greater, potassium 6 mEq/L or greater, phosphorus 4.5 mg/dL or greater in adults, and calcium 7 mg/dL or less; the original definition also counts a 25 percent change from baseline. A uric acid of 8.2 mg/dL meets the hyperuricemia criterion, reflecting rapid breakdown of nucleic acids from lysed tumor cells, and it can cause uric acid crystal deposition in the renal tubules and acute kidney injury. Potassium 5.4 mEq/L is wrong because it is elevated but remains below the 6 mEq/L threshold, although the nurse should still monitor cardiac rhythm and trends. Phosphorus 4.0 mg/dL is wrong because it falls short of the adult threshold of 4.5 mg/dL. Calcium 7.8 mg/dL is wrong because the hypocalcemia criterion requires 7 mg/dL or less. For high-risk patients such as those with Burkitt lymphoma, the nurse ensures aggressive IV hydration, accurate intake and output, frequent electrolyte checks, and rasburicase or allopurinol as ordered, and promptly reports rising creatinine, arrhythmias, or muscle cramping.

B is correct.The federal Common Rule (45 CFR 46) adds specific subparts of protection for three groups: pregnant women, fetuses, and neonates in Subpart B; prisoners in Subpart C; and children in Subpart D. A 16-year-old student has not reached the legal age of consent, so enrollment requires permission from a parent or guardian plus the adolescent's own assent, and the institutional review board must apply the added risk and benefit limits for pediatric research. A 72-year-old retiree is not automatically vulnerable; older age alone does not trigger extra regulatory protections unless decision-making capacity is impaired, and excluding older adults solely by age is discouraged because they carry much of the cancer burden. A 45-year-old military veteran is a competent adult who gives his own informed consent, and veteran status is not one of the federally designated vulnerable groups. A 58-year-old rural farmer may face access barriers such as travel distance, which the team should address to promote equitable enrollment, but rural residence is not a protected research category. The nurse supports ethical research by recognizing these categories, confirming proper consent and assent, and reporting any concern about coercion or undue influence to the IRB.

A is correct.A healthcare proxy, or durable power of attorney for health care, gives the named agent authority to make medical decisions only after the patient has been formally determined, usually by the attending physician, to lack decision-making capacity. While the patient retains capacity, the patient's decision governs, even when the proxy or care team disagrees, because informed refusal is protected by the ethical principle of autonomy and by law. The proxy's decision is wrong because the document has not been activated; an alert patient who understands the risks, benefits, and alternatives remains the decision-maker. The oncologist's decision is wrong because a physician may recommend and explain treatment but cannot override an informed refusal by a capable adult. The ethics committee's decision is wrong because ethics consultation can help resolve conflict and support communication, but it does not transfer decision-making authority away from a capable patient. The nurse should confirm that capacity has been assessed and documented, make sure the patient understands the consequences of refusing, document the refusal, advocate for the patient's stated wishes, and support a family meeting so the proxy understands the patient's values before any future decisions are needed.