CEN common mistakes
CEN · Understand the traps and how to avoid them.
Ordering or giving sublingual nitroglycerin as the first action for a patient with an inferior STEMI (ST elevation in II, III, aVF), clear lungs, and a blood pressure of 84/50, without checking right-sided or posterior leads first.
Pattern-matching "chest pain plus ST elevation equals nitro" from memorized ACS bundles; the candidate does not stop to ask whether the infarct is preload-dependent, so the hypotensive inferior/RV infarct presentation is treated like an uncomplicated anterior MI.
What to do instead
Build a reflex rule: for any ST elevation in II, III, or aVF, look at the blood pressure and consider right-sided leads (V4R) before nitro. If SBP is under 90 mmHg, lungs are clear, or RV involvement is suspected, withhold nitrates and treat with careful isotonic fluid boluses while arranging reperfusion.
Describing a patient with asthma who has a quiet chest, minimal wheeze, exhaustion, and a rising or normalizing PaCO2 as "improving" and selecting continued nebulizers with no escalation of care.
The candidate equates less wheeze with less obstruction and does not link a normal CO2 in a tiring asthmatic to hypoventilation and impending respiratory failure; the seductive 'fewer breath sounds' finding overrides the fatigue and mental status trend.
What to do instead
Assess and trend work of breathing, mental status, and speech rather than wheeze volume. Treat a silent chest, drowsiness, or a PaCO2 that is no longer low as impending failure: sit the patient up, continuous nebulized bronchodilators with ipratropium, early magnesium and steroid, and immediate escalation to the provider and respiratory therapy for ventilatory support.
Recording the time the patient was found, awoke with symptoms, or arrived in the ED as the stroke symptom onset time instead of the last time the patient was known to be neurologically normal.
The history is taken in the order questions occur to the candidate (when did it start?) rather than anchored to a verifiable external reference; wake-up strokes and aphasic or confused patients make the patient's own estimate the path of least resistance.
What to do instead
Ask every stroke patient or witness: 'When was the last moment you know this person was completely normal?' Use the last-known-well time as the onset for thrombolysis windows, and for wake-up strokes document the time last seen normal at bedtime, not the time of awakening.
Committing to the obvious orthopedic injury - spending time splinting an angulated femur or dressing a large laceration - before reassessing the airway and chest in a multi-system trauma patient.
The dramatic, visible deformity captures attention (a distracting injury), and the candidate treats the tasks in the order they are noticed rather than in the order of lethality.
What to do instead
Run an explicit ABCDE primary survey to completion, then a head-to-toe secondary survey with full exposure and log-roll, before any non-life-threatening intervention. Reassess ABCDE after every major intervention or move; life threats (tension pneumothorax, airway compromise, uncontrolled hemorrhage) always precede extremity care.
Choosing an insulin bolus as the first intervention for a patient in DKA who is hypotensive (88/52) or whose potassium is 3.1 mEq/L.
The candidate memorizes 'DKA equals insulin' as a single trigger-response pair and skips the two preconditions that make insulin safe: adequate volume resuscitation and a potassium level high enough that shifting it intracellularly will not cause a dysrhythmia.
What to do instead
Sequence it: isotonic fluid bolus first (typically 1 to 2 L), confirm the potassium before starting insulin, and hold insulin if K+ is below 3.3 mEq/L while replacing potassium per protocol. Frame every DKA answer around fluids, then potassium, then insulin.
Selecting flumazenil as the reversal agent for a patient with depressed mental status and a mixed overdose history that includes a benzodiazepine plus a possible tricyclic antidepressant or a seizure history.
The candidate matches drug class to antidote in isolation and does not screen for the specific contraindications, so a toxidrome-to-antidote shortcut overrides the co-ingestion history.
What to do instead
Before any reversal agent, read the ingestion history for co-ingestants and contraindications. Flumazenil is avoided in mixed overdoses with TCAs, in seizure-prone patients, and in chronic benzodiazepine users; treat with airway and ventilatory support and consult poison control instead.
Assigning a low acuity or a 'GI bug' label to a first-trimester pregnant patient with cramping, scant dark bleeding, and abdominal pain, without checking orthostatic vitals, ectopic risk factors, or a quantitative hCG.
The candidate anchors on the most benign and most common explanation (threatened miscarriage or gastroenteritis) and is reassured by a soft abdomen or a small amount of bleeding, so the potentially fatal diagnosis is never placed on the differential.
What to do instead
Treat every first-trimester pregnancy with pain or bleeding as an ectopic pregnancy until proven otherwise: full vitals including orthostatics, abdominal and adnexal assessment, quantitative beta-hCG, type and screen, and expedited ultrasound with OB/GYN notification. Ask specifically about shoulder pain, syncope, and previous ectopic or tubal surgery.
Documenting only a distal pulse after splinting or casting an extremity, and not reassessing neurovascular status after the splint or cast is in place.
Pulses are the easiest and most familiar thing to check, and the candidate considers the assessment complete once a pulse is found; compartment syndrome and nerve injury from a constricting device are silent to a pulse-only exam.
What to do instead
Use a structured five-P assessment (pallor, pain out of proportion, paresthesia, paralysis, pulses) plus capillary refill, two-point sensation, and motor function, on the affected and unaffected limbs, both before and after any splint, cast, or reduction. Document the reassessment time and escalate new paresthesia or disproportionate pain immediately.
Moving directly to physical restraints or chemical sedation for an agitated, combative patient without first obtaining point-of-care glucose, oxygen saturation, and a focused neuro exam.
The behavior is the loudest data point in the room, so the candidate treats agitation as the diagnosis rather than as a possible symptom of hypoglycemia, hypoxia, head injury, or anticholinergic toxicity.
What to do instead
Screen for reversible medical causes before restraint: glucose, SpO2, temperature, pupils, and a review of recent medications and injury. Then use the least restrictive effective intervention, follow restraint orders and monitoring requirements, and document the medical evaluation that justified the behavioral emergency.
Selecting 'complete an incident report' or 'document the fall' as the priority nursing action after an unwitnessed fall or a medication error, rather than reassessing the patient first.
Paperwork feels like the concrete, testable step, and the candidate conflates the quality-improvement task with the clinical priority; the answer option sounds procedurally correct and safe.
What to do instead
Rank every answer by patient-first sequencing: assess the patient (vitals, neuro, injury survey, glucose), intervene, notify the provider, then document and file the event report per policy. When two options both sound reasonable, choose the one that touches the patient before the one that touches the chart.