OCN common mistakes
OCN · Understand the traps and how to avoid them.
When a stem describes a patient with metastatic cancer who is still receiving chemotherapy and reports uncontrolled pain, the candidate selects 'refer to hospice' rather than 'palliative care consult.'
The candidate treats palliative care and hospice as synonyms, so any mention of advanced disease triggers the hospice answer even though the patient is still pursuing disease-directed therapy.
What to do instead
Write the two definitions side by side and recite them: palliative care = symptom relief at any point in the illness, delivered alongside curative or life-prolonging treatment; hospice = a benefit for a prognosis of roughly six months or less with comfort as the goal and disease-directed therapy forgone. Before answering, check the stem for whether treatment is continuing.
The candidate answers that the nurse 'obtains informed consent' for a clinical trial or chemotherapy, or states the nurse may sign as the witness and answer the patient's questions about risks in place of the provider.
Nurses witness consent signatures daily, so the witnessed signature becomes encoded in memory as the nurse 'getting the consent.'
What to do instead
Fix the division of labor in one sentence: the provider discloses risks, benefits, and alternatives and obtains consent; the nurse may witness the signature, verify the patient's understanding, and advocate if understanding is questionable, but cannot obtain consent or answer risk questions on the provider's behalf.
For a patient whose platelet count is in the 40,000s/µL, the candidate accepts an ordered intramuscular injection and a rectal suppository as routine care, or accepts a rectal temperature.
General med-surg practice is the default mental model, so routes are chosen for convenience without screening against oncology-specific counts.
What to do instead
Build a 'count → route' checklist you can recall cold: low platelets mean no intramuscular injections, no rectal medications or temperatures, and no vigorous flossing or enemas; use oral, IV, or transdermal routes and report signs of bleeding.
For a vesicant extravasation, the candidate selects warm compresses for an anthracycline or cold compresses for a vinca alkaloid, and mismatches the antidote (e.g., hyaluronidase for an anthracycline).
The candidate memorizes 'extravasation = stop infusion and apply compress' as one undifferentiated bundle instead of separate drug-class rules.
What to do instead
Make a three-column table and drill it: anthracycline → stop, aspirate, cold compress, dexrazoxane; vinca alkaloid → stop, aspirate, warm compress, hyaluronidase; mechlorethamine → sodium thiosulfate. Attach the antidote to the class, not to 'extravasation' in general.
The candidate restricts visitors, separates eating utensils, and limits time at the bedside of a patient who has completed a course of external beam radiation, or relaxes precautions for a patient with an indwelling brachytherapy source.
'Radiation' is stored as a single undifferentiated hazard, so external beam and sealed/unsealed sources collapse into one rule set.
What to do instead
Learn the source distinction: after external beam therapy the patient is not radioactive and needs no radiation precautions; sealed implants require time-distance-shielding while the source is in place; unsealed therapies such as iodine-131 require body-fluid and proximity precautions for a defined period. Ask 'where is the source?' before answering.
A patient on long-acting morphine with five days without a bowel movement and new diffuse abdominal pain is answered with 'escalate the opioid dose,' rather than 'assess for constipation and add a bowel regimen.'
The reflex 'pain = more opioid' bypasses the search for a cause, and opioid-induced constipation is under-recalled as a pain generator.
What to do instead
Use a mandatory four-step gate before any dose increase: characterize the pain, look for a reversible cause (constipation, impaction, urinary retention, infection, progression), check the around-the-clock bowel regimen, then adjust the opioid.
For a dying patient with visible air hunger and a normal or near-normal oxygen saturation, the candidate selects 'increase the oxygen flow rate' instead of 'administer an opioid.'
Dyspnea is mentally paired with oxygen, and the candidate answers from that pairing rather than from the goal of relieving the patient's subjective sensation.
What to do instead
Anchor the rule: opioids are first-line for dyspnea at end of life; oxygen is for documented hypoxemia and adds little otherwise. When the stem gives a reassuring saturation, treat that as the cue to choose the opioid, with a fan or open window as an adjunct.
In a stem describing a temperature of 38.4°C on day 10 after chemotherapy, the candidate selects 'draw blood cultures and wait for results before starting antibiotics,' or otherwise sequences cultures ahead of antibiotics.
The candidate carries forward the general principle of culture-before-treatment and applies it to a population in which delay is the harm.
What to do instead
Memorize the target: febrile neutropenia is a time-critical emergency, and antibiotics are started within about one hour of the fever, with cultures drawn concurrently rather than sequentially. Read any 'await results' option as a distractor.
Asked to identify the earliest laboratory indicator of tumor lysis syndrome or the most important preventive intervention, the candidate chooses rasburicase or a potassium-restricted diet.
Tumor lysis syndrome is stored as a list of treatments rather than as a time-ordered sequence of onset, so treatment options feel 'more correct' than monitoring options.
What to do instead
Rehearse the sequence out loud: rising potassium, phosphate, and uric acid with falling calcium appear first, followed by renal injury and arrhythmia; prevention is vigorous IV hydration plus allopurinol or rasburicase in high-risk patients. Match your answer to the verb in the question (identify, monitor, prevent, treat).
A hospitalized patient on day three of admission with fluctuating attention, agitation, and hallucinations is answered with 'explore feelings about the diagnosis' or 'discuss an antidepressant,' rather than 'assess for delirium and search for a cause.'
The candidate classifies all distress as psychological, and the acuity of a medical cause is missed because the behavior looks emotional.
What to do instead
Screen every acute behavioral change with a fluctuating-attention check; if attention waxes and wanes, work up the cause (infection, opioid or steroid effect, hypercalcemia, hypoxia, dehydration, brain involvement, urinary retention or constipation) and treat the cause before adding a psychotropic or a counseling intervention.