CNRN Practice Questions (2026) — Free Sample Questions with Answers

Answer: D

Recheck SpO₂ in 4 hours, since oxygenation is still normal: In neuromuscular failure, SpO₂ stays normal until late. Falling FVC and NIF signal impending respiratory failure despite good saturation.

Give an extra dose of pyridostigmine to boost muscle strength: Extra anticholinesterase can cause a cholinergic crisis and increases secretions. It does not treat a myasthenic crisis in which ventilation is failing.

Start high-flow oxygen by nonrebreather and keep monitoring: Oxygen does not fix hypoventilation caused by weak muscles. Delaying airway support risks an emergent, unplanned intubation.

Notify the provider and prepare for elective intubation: Correct. FVC is about 16 mL/kg (under 20 mL/kg) and NIF is weaker than -30 cm H₂O. These values meet the 20/30/40 criteria for impending myasthenic crisis, so controlled intubation or ventilation should be planned.

Myasthenic crisis '20/30/40 rule': FVC <20 mL/kg, NIF weaker than -30 cm H₂O or MEP <40 cm H₂O means prepare for ventilatory support. Pulse oximetry is a late sign.

Answer: C

Bolus 9 mg over 1 minute, then infuse 81 mg over 60 minutes: This uses the 90-mg maximum instead of the weight-based dose. The patient's total dose is 0.9 × 78 = 70.2 mg.

Bolus 7 mg over 1 minute, then infuse 70.2 mg over 60 minutes: This gives the full calculated dose as the infusion on top of the bolus, so the patient gets about 77 mg, more than ordered.

Bolus 7 mg over 1 minute, then infuse 63.2 mg over 60 minutes: Correct. Total dose = 0.9 mg/kg × 78 kg = 70.2 mg (below the 90-mg maximum). Ten percent (about 7 mg) is given as a 1-minute bolus, and the remaining 63.2 mg is infused over 60 minutes.

Bolus 4.7 mg over 1 minute, then infuse 42.1 mg over 60 minutes: This is based on 0.6 mg/kg (46.8 mg total), a low-dose regimen not used in standard US practice.

Alteplase for stroke: 0.9 mg/kg (max 90 mg), with 10% as a 1-minute bolus and the rest over 60 minutes. Remove excess drug from the vial so the patient gets only the calculated dose.

Answer: B

Contact precautions until the rash fades: Meningococcus spreads mainly by respiratory droplets. Contact precautions alone do not address that route.

Droplet precautions for 24 hours of antibiotics: Correct. Neisseria meningitidis needs droplet precautions until the patient has had 24 hours of effective antibiotic therapy.

Airborne precautions in a negative-pressure room: Airborne isolation is for organisms such as TB, measles and varicella, not meningococcus.

Standard precautions only, as antibiotics have begun: Three hours of therapy is not enough. Droplet precautions continue for the first 24 hours.

Suspected meningococcal meningitis: droplet precautions until 24 hours of effective antibiotics. Close contacts may need chemoprophylaxis.

Answer: C

Lay the patient flat and raise the legs to improve cerebral perfusion: Lying flat raises blood pressure further. Sitting upright with the legs down lowers it.

Give a prescribed antihypertensive before looking for a trigger: Medication is used if BP stays high after the cause is removed. Finding and removing the trigger comes first.

Sit the patient upright, loosen clothing and check the bladder: Correct. Sitting up causes orthostatic lowering of BP. Then look for the noxious stimulus below the injury, most often bladder distension or a kinked catheter, followed by bowel impaction.

Apply a cooling blanket because the sweating suggests a fever: Sweating here is a reflex response from autonomic dysreflexia, not fever. Cooling does nothing for the dangerous hypertension.

Autonomic dysreflexia (injury at T6 or above): sit upright, loosen restrictive items, find and remove the trigger (bladder, then bowel, then skin), and give antihypertensives if needed.

Answer: C

CPP 88 mm Hg, which is above target: This adds ICP to the systolic value or uses the wrong MAP. CPP is MAP minus ICP.

CPP 40 mm Hg, which shows critical ischemia: This subtracts ICP from the diastolic pressure (64 - 24) instead of from the MAP.

CPP 56 mm Hg, which is below target: Correct. MAP = (112 + 2 × 64) ÷ 3 = 80 mm Hg, and CPP = 80 - 24 = 56 mm Hg. That is below the recommended 60-70 mm Hg, and ICP is above the 22 mm Hg threshold, so report it and start ordered ICP and CPP treatment.

CPP 56 mm Hg, which is within target: The arithmetic is right, but 56 mm Hg is below the 60-70 mm Hg target range for severe TBI.

CPP = MAP - ICP, with MAP = (SBP + 2 × DBP) ÷ 3. Severe TBI targets: ICP below 22 mm Hg and CPP 60-70 mm Hg.

Answer: B

Wait to call the organ procurement organization until brain death is declared: Referral should not wait for brain death. Hospitals must notify the OPO in a timely way about imminent deaths, and donation after circulatory death may be possible.

Refer to the organ procurement organization now, per hospital triggers: Correct. Under CMS Conditions of Participation, the hospital must refer imminent deaths, such as a ventilated patient with severe neurological injury or a planned withdrawal discussion, to the OPO. The OPO then decides about and coordinates the family approach.

Ask the family about organ donation while they are at the bedside: The donation request should come from an OPO-designated or trained requestor, kept separate from the discussion about withdrawing care.

Avoid any donation contact because the family is focused on withdrawal: Leaving out the OPO violates referral requirements and takes away the family's chance to consider donation.

Notify the OPO early, when clinical triggers are met and before withdrawal discussions. Leave the donation request to trained OPO staff.