Free CEN Practice Questions 2026

✓ Correct Answer: B. Black widow spider envenomation

Why this is correct
Black widow venom is neurotoxic and can produce severe regional or generalized muscle spasm, abdominal-wall rigidity, diaphoresis, autonomic instability, nausea, and vomiting despite modest local findings. Analgesia, control of muscle spasm, monitoring, poison-center consultation, and selective consideration of antivenom are based on severity.

Why the other answers are incorrect

A. Brown recluse spider envenomation
Brown recluse bites more often evolve toward local ischemia, blistering, a violaceous lesion, and delayed necrosis. The dramatic muscle spasm and autonomic syndrome point away from loxoscelism.

C. Pit-viper envenomation
Pit-viper bites usually cause progressive local pain and swelling with possible coagulopathy and systemic toxicity rather than a small local lesion with intense generalized muscle cramping.

D. Scombroid fish poisoning
Scombroid poisoning follows ingestion of improperly stored fish and typically causes flushing, headache, palpitations, urticaria-like symptoms, and gastrointestinal upset. It does not cause fang marks or this neurotoxic spasm pattern.

🧠 Make It Stick
Black widow = neurotoxic and tight; brown recluse = tissue-toxic and necrotic.

💉 Clinical Connection
A rigid abdomen after a black-widow bite can mimic an acute surgical abdomen. Exposure history and the combination of muscle spasm, diaphoresis, and autonomic findings are key clues.

📚 Sources
Emergency Nurses Association. Emergency Nursing Core Curriculum, 8th ed. Chapter 12, Environmental Emergencies, Spider Envenomation, pp. 179–181.
Emergency Nurses Association. Sheehy's Manual of Emergency Care, 8th ed. Chapter 31, Bite and Sting Emergencies, Spider (Arachnid) Bites, p. 369.

✓ Correct Answer: C. Promptly drain the hematoma and apply a pressure dressing to prevent reaccumulation

Why this is correct
The findings describe an auricular hematoma, in which blood separates the perichondrium from the cartilage. Prompt drainage followed by a pressure dressing prevents reaccumulation and reduces the risk of cartilage necrosis and permanent cauliflower-ear deformity.

Why the other answers are incorrect

A. Apply ice only and arrange routine follow-up in 1 month
Observation alone allows the collection to organize and compromise cartilage nutrition, increasing the chance of permanent deformity.

B. Aspirate the swelling and discharge without a dressing
Drainage without compression leaves a potential space in which blood can rapidly reaccumulate.

D. Incise the posterior ear and leave the wound open without compression
An open incision without compression does not address the tendency for blood to reaccumulate and adds avoidable wound-care risk.

🧠 Make It Stick
Drain it, then press it: auricular hematomas need both steps.

💉 Clinical Connection
Arrange timely reassessment because recurrence can occur even after appropriate drainage and compression.

📚 Sources
Emergency Nurses Association. Sheehy's Manual of Emergency Care, 8th ed. Chapter 19, Facial, Ocular, ENT, and Dental Trauma, Auricular Trauma, p. 224.
Emergency Nurses Association. Emergency Nursing Core Curriculum, 8th ed. Chapter 31, Facial, Ocular, ENT, and Dental Trauma, external-ear injury considerations.

✓ Correct Answer: A. Keep the binder in place, document its application time, and defer removal until a provider able to control pelvic bleeding is present

Why this is correct
A correctly placed pelvic binder reduces pelvic volume and helps tamponade hemorrhage. Premature removal can disrupt this stabilization and precipitate recurrent bleeding; it should remain in place until a clinician capable of definitive hemorrhage control is present. Application time and skin surveillance should be documented and coordinated without sacrificing hemostasis.

Why the other answers are incorrect

B. Remove the binder briefly, then reapply it after the examination
Even brief removal can release tamponade and destabilize clot formation in a patient who remains at high risk for pelvic hemorrhage.

C. Loosen the binder and slide it upward over the iliac crests
A binder belongs over the greater trochanters, not the iliac crests. Moving it upward reduces its ability to close and stabilize the pelvic ring.

D. Logroll the patient repeatedly to inspect the sacrum while the binder is off
Repeated logrolling can worsen instability and bleeding. Posterior assessment should use a coordinated lift or other trauma-team method when the patient's condition permits.

🧠 Make It Stick
Pelvic binder: low over the trochanters, time-stamped, and left on until bleeding control is ready.

💉 Clinical Connection
Continue balanced hemorrhage resuscitation and reassess perfusion. Binder use is a bridge to definitive pelvic hemorrhage control, not definitive treatment.

📚 Sources
Emergency Nurses Association. Emergency Nursing Core Curriculum, 8th ed. Chapter 28, Abdominal, Pelvic, and Genitourinary Trauma, Pelvic Fractures, pp. 486–488.
Emergency Nurses Association. Sheehy's Manual of Emergency Care, 8th ed. Chapter 10, Patient Care Management, trauma secondary assessment and pelvic-binder placement.

✓ Correct Answer: D. Immediately lift or remove the dressing to vent trapped air while activating emergency pleural decompression

Why this is correct
The abrupt combination of respiratory distress, hypotension, jugular venous distention, and unilateral absent breath sounds indicates tension pneumothorax. If the wound dressing has become an unintended one-way seal, immediately lifting or removing it can vent trapped air while the team performs definitive emergent pleural decompression and prepares for a chest tube.

Why the other answers are incorrect

A. Reinforce the dressing so all four sides are sealed
Sealing all four sides can worsen the one-way-valve effect and accelerate tension physiology by preventing air from escaping.

B. Obtain a portable chest radiograph before changing the dressing
A clinically evident tension pneumothorax is treated immediately. Waiting for radiographic confirmation delays relief of life-threatening obstructive shock.

C. Place the patient supine and give a rapid crystalloid bolus while leaving the dressing intact
Fluid may temporarily support circulation but does not relieve the obstructing intrathoracic pressure. Leaving the causative seal in place allows deterioration to continue.

🧠 Make It Stick
Open chest wound + sudden shock after sealing = vent the seal, then decompress the chest.

💉 Clinical Connection
Continue oxygenation and monitoring while emergency decompression occurs. Do not let imaging delay treatment when tension physiology is clinically apparent.

📚 Sources
Emergency Nurses Association. Sheehy's Manual of Emergency Care, 8th ed. Chapter 14, Chest Trauma, Open Pneumothorax, p. 160.
Emergency Nurses Association. Emergency Nursing Core Curriculum, 8th ed. Chapter 34, Thoracic Trauma, Pneumothorax, p. 583.

✓ Correct Answer: C. Mallory-Weiss syndrome

Why this is correct
Forceful retching can create a longitudinal mucosal tear at the gastroesophageal junction, producing hematemesis. The absence of severe chest or neck pain, respiratory distress, crepitus, or systemic toxicity makes a transmural esophageal rupture less likely.

Why the other answers are incorrect

A. Ruptured esophageal varices
Variceal hemorrhage is associated with portal hypertension and may cause large-volume bleeding without the classic retching-then-bleeding sequence described here.

B. Boerhaave syndrome
Boerhaave syndrome is a full-thickness esophageal rupture. It typically produces severe chest or neck pain and may cause dyspnea, subcutaneous emphysema, mediastinitis, and rapid systemic deterioration.

D. Aortoenteric fistula
An aortoenteric fistula is most strongly associated with prior aortic reconstruction or aneurysmal disease and may present with a herald gastrointestinal bleed followed by catastrophic hemorrhage.

🧠 Make It Stick
Mallory-Weiss = mucosal tear and blood; Boerhaave = full-thickness rupture and chest catastrophe.

💉 Clinical Connection
Even an apparently stable upper gastrointestinal bleed requires vascular access, trending of perfusion and hemoglobin, and escalation if bleeding recurs or instability develops.

📚 Sources
Emergency Nurses Association. Sheehy's Manual of Emergency Care, 8th ed. Chapter 20, Abdominal and Genitourinary Emergencies, Mallory-Weiss Syndrome, p. 240.
Emergency Nurses Association. Sheehy's Manual of Emergency Care, 8th ed. Chapter 14, Chest Trauma, Esophageal Rupture and Boerhaave Syndrome.

✓ Correct Answer: A. Use a routine clinical reason to separate them, obtain a qualified interpreter if needed, and assess the patient privately with trauma-informed questions

Why this is correct
Control of identification, speaking for the patient, refusing separation, and rehearsed or fearful behavior are trafficking red flags. Confidentiality and privacy are essential: the nurse should create a safe opportunity to assess the adult patient alone, use a qualified interpreter rather than the companion, and ask nonjudgmental trauma-informed questions.

Why the other answers are incorrect

B. Confront the supervisor and state that human trafficking is suspected
Confrontation can escalate danger for the patient and staff, destroy rapport, and remove the opportunity for a private assessment and safety plan.

C. Immediately call law enforcement and detain the supervisor without first assessing the adult patient privately
For an adult who is not in immediate danger, law-enforcement involvement is generally patient-directed unless jurisdictional mandatory-reporting requirements apply. The first safe step is private assessment.

D. Ask the trafficking-screening questions through the supervisor to avoid upsetting the patient
Screening through the controlling companion undermines confidentiality and may prevent honest disclosure or increase retaliation risk.

🧠 Make It Stick
Red flags open the door; privacy opens the conversation.

💉 Clinical Connection
If trafficking is disclosed, follow local law and hospital policy, offer patient-directed advocacy and safety resources, and avoid placing sensitive information where a controlling person may access it.

📚 Sources
Emergency Nurses Association. Emergency Nursing Core Curriculum, 8th ed. Chapter 38, Forensic Aspects of Emergency Nursing, Human Trafficking, pp. 655–657.
Emergency Nurses Association. Sheehy's Manual of Emergency Care, 8th ed. Chapter 28, Interpersonal Violence and Abuse, Human Trafficking, p. 336.
Follow current jurisdictional reporting requirements and institutional policy; adult law-enforcement engagement is generally consent-based unless immediate danger or mandatory reporting applies. HHS ASPR overview for health professionals: https://www.aspr.gov/readiness-response/response-operations/risk-individuals/access-functional-needs-cross-cutting-resources/human-trafficking-health-professionals-questions

✓ Correct Answer: B. Failure to sense

Why this is correct
Failure to sense, also called undersensing, occurs when the pacemaker does not detect the patient's intrinsic depolarizations. The device therefore fires in competition with the native rhythm, producing inappropriate pacing spikes after native complexes or within vulnerable portions of repolarization.

Why the other answers are incorrect

A. Failure to capture
Failure to capture produces a pacing spike that is not followed by the expected atrial or ventricular depolarization. In this tracing, the defining problem is inappropriate firing despite native beats.

C. Oversensing
Oversensing occurs when the device mistakes noncardiac signals for intrinsic beats and withholds pacing. It more often produces missing pacing impulses or pauses, not spikes competing with native QRS complexes.

D. Failure to pace
Failure to pace means an expected pacing stimulus is absent, commonly because of battery, generator, lead, or connection failure. Pacing spikes are clearly present here.

🧠 Make It Stick
Sense = see. If the pacemaker fails to 'see' native beats, it fires when it should stay quiet.

💉 Clinical Connection
Assess perfusion and symptoms, maintain continuous monitoring, place external pacing/defibrillation pads when clinically indicated, and expedite device evaluation because competitive pacing can be dangerous.

📚 Sources
Emergency Nurses Association. Emergency Nursing Core Curriculum, 8th ed. Chapter 10, Cardiovascular Emergencies, Paced Rhythms and Cardiac Implantable Electronic Device Malfunction, pp. 143–145.
Emergency Nurses Association. Sheehy's Manual of Emergency Care, 8th ed. Chapter 12, Cardiovascular Emergencies, Cardiac Implantable Devices and pacing assessment, pp. 143–145.

✓ Correct Answer: D. Administer intravenous propranolol for adrenergic control

Why this is correct
Propranolol is a nonselective beta blocker that can provoke or worsen bronchospasm and is contraindicated in a patient with active asthma. Adrenergic and rate control must be individualized with the treating team while airway, cooling, antithyroid, corticosteroid, and precipitant-directed care continue.

Why the other answers are incorrect

A. Begin external cooling and administer acetaminophen
Aggressive cooling and acetaminophen address severe hyperthermia. Aspirin is generally avoided because it can increase free thyroid hormone levels.

B. Give methimazole, followed at least 1 hour later by iodine
A thionamide is given before iodine so newly available iodine is not used as substrate for additional hormone synthesis. Iodine is generally delayed by at least 1 hour.

C. Administer intravenous hydrocortisone
Glucocorticoids help reduce peripheral conversion of T4 to T3 and support the stress response in thyroid storm.

🧠 Make It Stick
Thyroid storm likes beta blockade; active asthma does not. Check the patient's airway disease before giving a nonselective agent.

💉 Clinical Connection
Thyroid storm treatment is a coordinated bundle. Do not let one contraindicated component delay cooling, thionamide therapy, corticosteroids, supportive care, and treatment of the trigger.

📚 Sources
Emergency Nurses Association. Sheehy's Manual of Emergency Care, 8th ed. Chapter 32, Metabolic Emergencies, Acute Thyrotoxicosis and Thyroid Storm, pp. 379–380.
Emergency Nurses Association. Emergency Nursing Core Curriculum, 8th ed. Chapter 11, Metabolic Emergencies, Thyroid Storm, pp. 165–166.
NIH DailyMed current propranolol injection label lists bronchial asthma as a contraindication: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d0a8c5d1-bfc1-4829-bbf4-609e05e6d25c

✓ Correct Answer: A. Place a loose sterile absorbent pad beneath the ear, allow drainage, and continue neurologic monitoring

Why this is correct
Mastoid ecchymosis and watery otorrhea suggest a basilar skull fracture with a cerebrospinal-fluid leak. The drainage should be allowed to escape into a loose absorbent dressing; nothing should be inserted into or used to occlude the ear. Serial neurologic assessment and escalation of the suspected skull-base injury remain priorities.

Why the other answers are incorrect

B. Pack the ear canal tightly with sterile gauze to stop the leak
Tightly packing the canal obstructs drainage and may increase the risk of contamination or pressure-related complications.

C. Irrigate the ear canal and inspect it with a cotton-tipped applicator
Irrigation and probing can introduce organisms or traumatize injured structures. Only the external ear should be gently cleansed if needed.

D. Insert a nasogastric tube to reduce pressure contributing to the leak
Nasal instrumentation is avoided when a basilar skull fracture is suspected because the device can enter the cranial vault. If gastric decompression is required, an oral route is used.

🧠 Make It Stick
CSF should flow, not be plugged: loose pad outside, nothing inside.

💉 Clinical Connection
Document the amount and character of drainage, avoid nose blowing or straining, and watch for neurologic change or infection.

📚 Sources
Emergency Nurses Association. Sheehy's Manual of Emergency Care, 8th ed. Chapter 17, Head, Neck, and Vertebral Column Trauma, Basilar Skull Fracture, pp. 192–194.
Emergency Nurses Association. Emergency Nursing Core Curriculum, 8th ed. Chapter 30, Head Trauma, Skull Fractures, p. 519.

✓ Correct Answer: B. Provide routine postbirth care and observation without routine oral, nasal, or tracheal suctioning

Why this is correct
This newborn is vigorous, with effective breathing, good tone, and a heart rate above 100/min. Meconium-stained fluid alone is not an indication for routine oral, nasal, or endotracheal suctioning. The newborn should receive routine postbirth care and observation; suctioning is reserved for evidence of airway obstruction or ineffective ventilation.

Why the other answers are incorrect

A. Perform immediate laryngoscopy and tracheal suctioning because meconium is present
Routine laryngoscopy and tracheal suctioning are not recommended solely because meconium is present. This vigorous newborn has no sign of an obstructed airway.

C. Begin positive-pressure ventilation despite the effective respirations and normal heart rate
Positive-pressure ventilation is indicated for apnea, gasping, or a heart rate below 100/min. None of those findings is present.

D. Separate the newborn for gastric lavage before initiating skin-to-skin care
Gastric lavage is not routine care for meconium exposure and would unnecessarily interrupt normal postbirth care and family contact.

🧠 Make It Stick
Meconium changes what you watch for, not whether every vigorous newborn gets suctioned.

💉 Clinical Connection
Continue routine thermal care and observation. If breathing becomes ineffective or the heart rate falls below 100/min, prioritize ventilation and suction only when obstruction prevents effective breaths.

📚 Sources
American Heart Association. 2025 Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, Part 5: Neonatal Resuscitation, Clearing the Airway and Ventilatory Support.
Emergency Nurses Association. Emergency Nursing Core Curriculum, 8th ed. Chapter 20, Neonatal Resuscitation, pp. 364–365.
https://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines/neonatal-resuscitation