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

Answer: B

Cuff volume shrinks; add air to keep a seal as altitude rises: Gas expands, not contracts, as barometric pressure falls during ascent (Boyle's law), so adding air would push the pressure even higher.

Cuff gas expands; recheck with a manometer and keep 20–30 cm H2O: Correct. Lower barometric pressure at altitude expands the air in the cuff, raising pressure on the tracheal mucosa; check cuff pressure during ascent and descent and adjust to 20–30 cm H2O.

No change occurs because ground transport is not affected by altitude: Ground routes through mountains do involve large changes in altitude, and gas laws apply to any air-filled space.

Cuff pressure falls; switch to an uncuffed tube before the ascent: Changing the tube adds airway risk for no benefit, and the cuff pressure will rise rather than fall.

Boyle's law: as barometric pressure falls, gas volume rises. Check ETT cuffs, pneumothoraces, NG tubes and air splints during altitude changes, even on the ground.

Answer: C

Metabolic acidosis plus a separate respiratory acidosis: A separate respiratory acidosis would leave PaCO2 above the expected range (over 22 mm Hg).

Metabolic acidosis plus a separate respiratory alkalosis: A separate respiratory alkalosis would push PaCO2 below the expected range (under 18 mm Hg).

Metabolic acidosis with appropriate respiratory compensation: Correct. Expected PaCO2 = 1.5 × 8 + 8 = 20 ± 2 (18–22 mm Hg); 22 is within range. If the patient is intubated, the ventilator must keep this high minute ventilation.

Primary respiratory alkalosis with metabolic compensation: The pH is acidemic, so the main disorder is acidosis; low HCO3⁻ with low pH is metabolic acidosis.

Winter's formula: expected PaCO2 = 1.5 × HCO3⁻ + 8 (± 2). Intubating a compensating DKA patient without matching their high minute ventilation can cause rapid, severe acidemia.

Answer: D

About 660 mL: This is 6 mL/kg of actual body weight (110 kg); tidal volume is based on predicted body weight, because lung size depends on height, not weight.

About 550 mL: This is 5 mL/kg of actual body weight, which still wrongly uses actual weight rather than predicted body weight.

About 880 mL: This is 8 mL/kg of actual weight and would overdistend the lungs.

About 440 mL: Correct. Predicted body weight (male) = 50 + 0.91 × (178 − 152.4) ≈ 73 kg; 6 mL/kg × 73 kg ≈ 440 mL, keeping plateau pressure at or below 30 cm H2O.

ARDS: start at 6 mL/kg of predicted body weight (male 50 or female 45.5 + 0.91 × [height in cm − 152.4]) and keep plateau pressure ≤30 cm H2O.

Answer: B

Withhold TXA, since it works only within 1 hour of injury: Benefit is greatest when given early, but the evidence supports giving TXA up to 3 hours after injury.

Give 1 g IV over 10 minutes now, then 1 g over 8 hours: Correct. CRASH-2 dosing for bleeding trauma patients within 3 hours of injury is a 1 g load over 10 minutes followed by a 1 g infusion over 8 hours.

Give 1 g by rapid IV push over 1 minute for faster effect: Rapid TXA push can cause hypotension; the loading dose is infused over about 10 minutes.

Give TXA at any time until the bleeding has stopped: Starting TXA more than 3 hours after injury was linked to higher death from bleeding in CRASH-2, so it is not started late.

TXA in trauma: within 3 hours of injury, 1 g over 10 minutes plus 1 g over 8 hours. After 3 hours, starting it may cause harm.

Answer: B

Continue monitoring, since BP up to 220/120 is allowed: Permissive hypertension up to 220/120 applies only to patients who did not receive a thrombolytic.

IV labetalol or nicardipine to below 180/105: Correct. After thrombolysis, BP must be kept below 180/105 mm Hg for 24 hours to reduce the risk of symptomatic intracranial hemorrhage.

Lower BP quickly to below 120/80 to prevent bleeding: Lowering BP too far can reduce blood flow to the ischemic penumbra and expand the infarct.

Give sublingual nifedipine for rapid BP control: Sublingual nifedipine causes unpredictable, sudden drops in BP and is not recommended.

Stroke BP thresholds: before thrombolysis <185/110; after thrombolysis <180/105 for 24 h; without thrombolysis, treat only if >220/120.

Answer: C

Place her in Trendelenburg position on the board: Trendelenburg does not relieve compression of the vena cava by the uterus and can impair breathing.

Start a dopamine infusion to support BP: Vasopressors are not first-line here; correcting the positional cause restores venous return.

Manually displace the uterus to her left: Correct. After about 20 weeks, the uterus compresses the inferior vena cava when the patient is supine; manual left uterine displacement or tilting the whole board restores preload.

Raise both legs and keep her flat on her back: Leg elevation alone leaves the vena cava compressed while she stays flat.

Pregnancy over 20 weeks: avoid lying flat on the back. Use manual left uterine displacement or tilt the backboard to relieve aortocaval compression.