Free CEN practice questions

Answer: C

• A. A 25% reduction in the first hour is the adult rule of thumb; in children the 25% applies to the planned reduction and is spread over about 8 hours.
• B. The stage 2 threshold defines the severity of chronic hypertension; it is not a target for emergency lowering and would mean a drop of nearly 50 mm Hg in 6 hours.
• C. Correct. The planned reduction is 175 minus 115, or 60 mm Hg; no more than 25% of it, about 15 mm Hg, is taken off in the first 8 hours, and the rest more slowly.
• D. The 95th percentile is the eventual short-term goal, but reaching it within hours risks cerebral and renal hypoperfusion in a child whose autoregulation has adapted.

Acute poststreptococcal glomerulonephritis is a classic cause of acute severe hypertension in school-age children, and headache, vomiting and confusion point to hypertensive encephalopathy. The AAP 2017 guideline recommends immediate treatment with a short-acting agent, reducing BP by no more than 25% of the planned reduction over the first 8 hours and the rest over the following 12 to 24 hours, toward a short-term goal near the 95th percentile; the Merck Manual's approach spreads the remainder so the goal is reached over about 48 hours. Here the planned systolic reduction is 60 mm Hg, so the 8-hour goal is about 160 mm Hg. Lowering faster can cause cerebral ischemia and acute kidney injury, because autoregulation has shifted to the higher pressure.

Sources: Merck Manual, Professional Version

Answer: B

• A. Crackles, elevated JVP, and edema indicate congestion (“wet”).
• B. Correct. Congestion with adequate perfusion is the most common profile and is treated with IV loop diuretics, with or without vasodilators.
• C. This patient is clearly congested. Fluids would worsen the pulmonary edema.
• D. Warm extremities, normal mentation, normal lactate, and stable renal function argue against hypoperfusion (“cold”).

Bedside hemodynamic profiling classifies acute heart failure by congestion (wet or dry) and perfusion (warm or cold). Signs of congestion include orthopnea, elevated JVP, crackles, edema, and an S3. Signs of hypoperfusion include cool extremities, narrow pulse pressure, altered mentation, rising lactate, and worsening renal function. “Warm and wet” patients are treated with IV loop diuretics (commonly 1–2.5 times the home oral dose given IV), with vasodilators if hypertensive, while GDMT is continued when possible.

Sources: Jacobson, CV Nursing Practice, 3rd ed.; ACC Hospitalized HF Decision Pathway (2024); AHA/ACC/HFSA Heart Failure Guideline (2022)

Answer: C

• A. Bronchospasm causes wheezing and high airway pressures, but not generalized rigidity immediately after a fentanyl bolus.
• B. The timing with a rapid fentanyl push and generalized rigidity points to drug-induced chest wall rigidity.
• C. Correct. Rapid high-dose potent opioids can cause truncal and laryngeal rigidity, which is treated with a neuromuscular blocker (or naloxone).
• D. Fentanyl causes minimal histamine release, and the finding here is muscle rigidity.

Opioid-induced chest wall rigidity (“wooden chest”) is linked to rapid IV administration of high-dose lipophilic opioids (fentanyl, sufentanil, remifentanil). It is thought to be centrally mediated and can make ventilation impossible, with vocal cord closure contributing. Treatment is neuromuscular blockade with intubation, or naloxone if airway control is not planned. Prevention includes slower administration and giving the paralytic promptly during rapid-sequence intubation.

Sources: Mosby's 2026 Nursing Drug Reference; Walls Manual of Emergency Airway, 6th ed.

Answer: D

• A. Adding anaerobic coverage feels logical after a witnessed choking episode, but the guideline suggests not routinely adding it unless lung abscess or empyema is suspected, and imaging shows neither.
• B. Clindamycin is a traditional aspiration choice, but it is not a recommended pneumonia regimen on its own, and the guideline notes its frequent link to Clostridioides difficile infection.
• C. Nursing home residence once defined health care-associated pneumonia and triggered broad coverage, but that category has been abandoned; MRSA or Pseudomonas coverage is added only for validated risk factors, which this patient lacks.
• D. Correct. A beta-lactam plus a macrolide is a standard regimen for nonsevere inpatient pneumonia without MRSA or Pseudomonas risk factors, and suspected aspiration alone does not change it.

The 2019 ATS/IDSA guideline recommends a beta-lactam such as ceftriaxone plus a macrolide, or a respiratory fluoroquinolone alone, for adults admitted with nonsevere community-acquired pneumonia who have no risk factors for MRSA or Pseudomonas aeruginosa. It suggests not routinely adding anaerobic coverage for suspected aspiration pneumonia unless a lung abscess or empyema is suspected, because modern studies show that anaerobes play a small role and added agents such as clindamycin raise the risk of C. difficile. It also recommends abandoning the old health care-associated pneumonia category: living in a nursing home does not by itself justify vancomycin and an antipseudomonal drug, which are reserved for prior respiratory isolation of those organisms or locally validated risk factors such as recent hospitalization with IV antibiotics. The nurse gives the first doses promptly, keeps the head of the bed raised and the patient on nothing by mouth until a swallow screen, and reports any worsening oxygenation.

Sources: Merck Manual, Professional Version; ATS/IDSA Community-Acquired Pneumonia in Adults (2019)

Answer: D

• A. A specimen is needed, but an indwelling bladder catheter is itself a precipitating factor for delirium and adds a tube she may pull at; a straight-catheter or clean-catch specimen meets the need.
• B. Antipsychotics are reserved for severe agitation that threatens essential treatment or safety; the Beers Criteria advise avoiding them in delirium unless nonpharmacologic measures have failed.
• C. A quiet setting helps, but darkness and isolation remove orienting cues and the familiar person who calms her, which tends to worsen confusion at night.
• D. Correct. Family involvement for reorientation and comfort is first-line, nonpharmacologic management of delirium, and the patient is already calling for her daughter.

An acute worsening in a patient with dementia is delirium superimposed on dementia until proven otherwise, and fever with a suspected urinary infection is a likely cause. While the infection is treated, Inouye's Lancet review lists nonpharmacologic measures as first-line management: removing anticholinergic and psychoactive drugs, involving family or a companion for reorientation and comfort, nonpharmacologic sleep support, a quiet but well-cued environment and attention to pain. The same review lists physical restraints, bladder catheters and psychoactive drugs among the precipitating factors for delirium, and the 2023 Beers Criteria advise avoiding antipsychotics for delirium unless nonpharmacologic options have failed or the patient threatens substantial harm. Asking the daughter to stay, if she can, gives the patient a familiar person and keeps her safer on the stretcher without restraints, sedation or an indwelling catheter.

Sources: Inouye et al., Lancet (2014); AGS Beers Criteria (2023)

Answer: A

• A. Correct. A falling score with a unilateral dilated pupil is herniation from rising intracranial pressure and needs urgent intervention.
• B. A flat position raises intracranial pressure; the head stays at 30 degrees.
• C. Vigorous suctioning spikes intracranial pressure.
• D. Waiting risks irreversible brain injury.

Signs of rising intracranial pressure: decreasing level of consciousness (the earliest), pupil changes, motor weakness, and late Cushing triad (hypertension with widened pulse pressure, bradycardia, irregular respirations). Nursing care keeps the head midline and elevated, avoids Valsalva, and treats fever, pain and hypoxia.

Bottom line: A falling level of consciousness, the earliest sign of rising intracranial pressure, plus a new unilateral dilated pupil signals herniation and requires immediate provider notification.

Sources: Ignatavicius, Med-Surg Nursing, 11th ed.; Lewis's Medical-Surgical Nursing, 13th ed.

Answer: B

• A. A lap belt does not cross the chest.
• B. Correct. A lap belt without a shoulder belt folds the body over it, tearing bowel and fracturing the lumbar spine.
• C. A lap belt that rides above the iliac crests loads the abdomen and lumbar spine, not the pelvis; the classic pattern is hollow viscus injury and a Chance fracture.
• D. The pain and bruising are in the abdomen and low back.

The seat belt sign, a transverse band of ecchymosis across the abdomen, is a marker of serious injury: bowel perforation, mesenteric tears, pancreatic injury and a Chance fracture of the lumbar spine from flexion over the belt. The paramedic applies spinal motion restriction, examines the abdomen for peritoneal signs, and transports to a trauma center even when the patient looks well initially.

Sources: NAEMT PHTLS, 10th ed.; Emergency Care in the Streets, 9th ed.

Answer: A

• A. Correct. A single diagnostic study is expected to stay below the dose linked to fetal anomalies or loss, and a missed injury such as a splenic laceration threatens the fetus far more than the scan does.
• B. Tempting because observation spares radiation, but she is tachycardic with left upper quadrant pain after a fall, and a delayed diagnosis of bleeding endangers both mother and fetus.
• C. Tempting because MRI avoids ionizing radiation and is used in pregnancy, but it is often slow to arrange and impractical for an unstable trauma patient, and delay is the larger danger to both of them.
• D. Tempting because shielding sounds protective, but the uterus lies inside the area an abdominal and pelvic CT must image, so a shield over it would block the very region being examined.

Fetal dose estimates for an abdominal and pelvic CT vary with the scanner and protocol, but StatPearls, citing ACOG, states that x-ray exposure from a single diagnostic procedure does not cause harmful fetal effects and that concern about radiation should not prevent medically indicated studies. CDC states that non-cancer effects are not detectable below about 0.1 Gy and that diagnostic exams are unlikely to harm the fetus. Fear of radiation should not delay indicated imaging, because a missed maternal injury is the greater fetal risk. The nurse explains this, involves the provider and respects an informed refusal if she still declines.

Sources: StatPearls (NCBI Bookshelf); StatPearls: Pregnancy Trauma (2022); CDC: Radiation and Pregnancy, Information for Clinicians (2025)

Answer: A

• A. Correct. A limb held still in hot water burns evenly up to a sharp, matching water line in a stocking pattern, which a child scrambling in the water does not produce.
• B. This is the splash pattern of a child moving in or out of hot water, which fits the father’s account rather than contradicting it.
• C. Delay in seeking care is a red flag, but prompt arrival after cool-water first aid is what a caregiver of an accidentally burned child would do.
• D. Distress is common in caregivers of accidentally injured children and is not a reliable sign of abuse; the burn pattern is more informative than demeanor.

Forced immersion produces burns of uniform depth with sharp, symmetric lines of demarcation in a stocking or glove distribution, often without splash marks because the limb is held still. Flexed skin creases may be spared (“zebra stripes”), and the center of the buttocks may be spared where it pressed against the cooler tub. A child who climbs or falls into hot water moves and splashes, which gives irregular margins, variable depth and drip marks. Other red flags are isolated burns of the buttocks or perineum, a story that does not fit the child’s development and delayed care. A suspicious pattern is reported to child protective services.

Sources: Nonaccidental Trauma Review, Cureus (2022); ENA ENPC Provider Manual, 6th ed.; Wong's Care of Infants & Children, 12th ed.; Sheehy's Emergency Nursing, 7th ed.

Answer: C

• A. Sedatives worsen respiratory depression.
• B. Rapid rewarming causes vasodilation and cardiovascular collapse; passive rewarming is used.
• C. Correct. Myxedema coma threatens the airway and ventilation, so the nurse watches closely for hypoventilation; thyroid hormone is replaced intravenously.
• D. Oral absorption is unreliable in myxedema coma.

Myxedema coma: hypothermia, bradycardia, hypotension, hypoventilation, hyponatremia and decreased consciousness in a client with untreated hypothyroidism. Care is airway support, IV levothyroxine, hydrocortisone until adrenal insufficiency is excluded, passive rewarming, and treating the precipitant, often infection.

Bottom line: Myxedema coma threatens airway and ventilation, so the priority is airway support and monitoring for hypoventilation while IV levothyroxine is prepared.

Sources: Ignatavicius, Med-Surg Nursing, 11th ed.; Lewis's Medical-Surgical Nursing, 13th ed.

Answer: C

• A. Calcium is low, not high, in this pattern.
• B. Adrenal insufficiency causes hyperkalemia with hyponatremia, not hyperphosphatemia and hyperuricemia.
• C. Correct. Rapid cell death releases potassium, phosphate, and nucleic acids (uric acid); phosphate binds calcium, causing hypocalcemia.
• D. Refeeding causes low phosphate, potassium, and magnesium as cells take up nutrients.

Tumor lysis syndrome occurs when chemotherapy kills a large tumor burden quickly. Priorities are aggressive IV hydration, treating hyperkalemia, rasburicase or allopurinol for uric acid, and monitoring for AKI and arrhythmias. Calcium is replaced only if symptomatic, because giving it with high phosphate precipitates calcium phosphate in the kidneys.

Sources: Brant, Oncology Nursing Core, 6th ed.; AACN Core Curriculum, 8th ed.

Answer: C

• A. Tempting for speed, but the part travels with the patient for possible reimplantation.
• B. Tempting because cold preserves tissue, but direct contact with ice damages it.
• C. Correct. The part stays cool and dry and does not touch the ice.
• D. Warmth is the opposite of what the part needs.

Amputated parts are transported with the patient for possible reimplantation. The model guideline keeps the part cool but dry: place it in a plastic bag, set that bag on ice in a second bag, and keep the part from touching the ice directly. The tourniquet stays in place and visible, with the application time marked. Pain is treated with analgesics, and the tourniquet is not loosened for comfort. Transport goes to a facility able to assess the limb.

Sources: NASEMSO Model EMS Guidelines v3.0 (2022)

Answer: B

• A. Moist heat and an NSAID are reasonable aftercare, which makes this tempting, but follow-up belongs with an oral surgeon or otolaryngologist within 1 to 2 days, and primary care cannot offer the procedures that treat recurrence.
• B. Correct. Teaching lowers the chance of the next episode, and a third dislocation in a teen with lax ligaments is recurrent dislocation, which a specialist can treat to stabilize the joint.
• C. Relaxants can ease spasm around a reduction, but they do not tighten the lax capsule and ligaments behind her recurrences, and dropping the diet and wide-opening limits removes the protection advised for 4 to 6 weeks.
• D. The teaching is correct, but recurrence is already established; without referral she is left to keep dislocating, and surgeon follow-up is advised after any reduction.

Akinbami's systematic review names lax capsules, weak ligaments and hypermobility syndromes such as Ehlers-Danlos and Marfan syndrome among the predisposing factors for dislocation, and chronic recurrent dislocation is the largest group in the literature. Recurrent cases are managed first with conservative procedures, such as sclerosing or autologous blood injections or botulinum toxin, and with eminectomy or eminoplasty when those fail, so the teen needs oral and maxillofacial follow-up. Merck's procedure advises a soft diet, no wide opening for 4 to 6 weeks, a fist under the chin when yawning and follow-up with an oral surgeon or otolaryngologist within 1 to 2 days, and its dislocation chapter says an oral and maxillofacial surgeon may be consulted for chronic dislocations.

Sources: Merck Manual Professional: How To Reduce a Mandibular Dislocation (2025); Merck Manual Professional: Mandibular Dislocation (2026); Akinbami, TMJ Dislocation: Systematic Review (2011); Lin et al., Patient-Guided TMJ Dislocation Reduction (2026)

Answer: B

• A. Hyperkalemia comes from cell destruction and does not reflect fluid status.
• B. Correct. Hourly urine output at or above 0.5 mL/kg/h is the best bedside measure of perfusion during burn resuscitation.
• C. A high hematocrit reflects hemoconcentration from inadequate fluid.
• D. Tachycardia suggests continuing hypovolemia.

Burn resuscitation (Parkland formula: 4 mL × kg × % burned of lactated Ringer’s over 24 hours, half in the first 8) is titrated to urine output of 0.5 mL/kg/h in adults (about 30 to 50 mL/h). Early complications include hypovolemic shock, hyperkalemia and airway edema in inhalation injury.

Bottom line: Burn fluid resuscitation is titrated to hourly urine output, with 0.5 mL/kg/h in adults indicating adequate perfusion.

Sources: Ignatavicius, Med-Surg Nursing, 11th ed.; ABA Burn Shock Resuscitation Guideline (2024)

Answer: B

• A. This pattern needs all three arms abnormal; only work of breathing is abnormal here.
• B. Correct. Abnormal work of breathing with normal appearance and normal circulation to the skin is the respiratory distress pattern.
• C. Retractions and flaring make failure tempting, but failure adds an abnormal appearance, and this child is alert, interactive and consolable.
• D. Shock is suggested by pallor, mottling or cyanosis of the skin; her color is pink.

The pediatric assessment triangle is a hands-off look and listen that takes seconds and needs no equipment. Appearance is judged with TICLS (tone, interactiveness, consolability, look or gaze, speech or cry); work of breathing covers abnormal sounds, positioning, retractions and flaring; circulation to the skin covers pallor, mottling and cyanosis. The pattern sorts the child: work of breathing alone abnormal means respiratory distress, adding abnormal appearance means respiratory failure, abnormal skin circulation means shock, and all three abnormal means cardiopulmonary failure. Any abnormal arm marks an unstable child, and ESI v5 warns that retractions in a child can precede a precipitous decline, so full vital signs follow at once.

Sources: Pediatric Assessment Triangle, J Emerg Nurs (2013); ENA ENPC Provider Manual, 6th ed.; ENA ESI Handbook, 5th ed.