RRT Practice Questions 2026: 8 Exam-Style Items Explained

Answer: A — Respiratory distress syndrome (surfactant deficiency)

Prematurity plus grunting and retractions in the first hours of life, with ground glass, air bronchograms and low lung volumes on the film, is the textbook picture of RDS: too little surfactant causes diffuse alveolar collapse. Grunting is the infant's way of holding end-expiratory pressure, which is why CPAP and surfactant are the core treatments. RDS is one of the two neonatal problems on the CSE.

• B. Meconium aspiration affects term and post-term infants, and its film shows patchy, coarse infiltrates with hyperinflation and air trapping, not uniform ground glass with low volumes.
• C. TTN usually affects term or near-term infants (often after cesarean delivery), shows fluid in the fissures and perihilar streaking, and typically clears within 24-72 hours.
• D. BPD is a chronic lung disease defined by a continuing oxygen need weeks after birth; it cannot be the diagnosis at 12 hours old.

Answer: C — Wearing gloves, drain the condensate away from the patient into a water trap or waste container and discard it as contaminated

Circuit condensate is quickly colonized by bacteria from the patient. CDC guidance is to drain and discard it periodically, never letting it run toward the patient, and to wear gloves and clean hands afterward. Left in place it also adds resistance, can cause auto-triggering and can be aspirated.

• A. Returning contaminated condensate to the humidifier seeds the reservoir with bacteria that are then carried to the patient.
• B. Draining condensate toward the patient delivers a contaminated bolus into the airway, a recognized risk for ventilator-associated pneumonia.
• D. Pooled water does not humidify the gas in any useful way; it obstructs the circuit, raises resistance, can cause auto-triggering and is an infection risk.

Answer: A — P(A-a)O2 about 9 mm Hg: the hypoxemia is explained by hypoventilation, so restoring ventilation is the priority

PAO2 = FiO2 x (PB - 47) - PaCO2/0.8 = 0.21 x 700 - 64/0.8 = 147 - 80 = 67 mm Hg, so P(A-a)O2 = 67 - 58 = 9 mm Hg, which is normal on room air. A normal gradient means the lungs are moving oxygen normally; the low PaO2 comes from CO2 crowding oxygen out of the alveoli. Treat the cause of hypoventilation (naloxone, ventilatory support if needed); oxygen alone would only hide it.

• B. 89 mm Hg comes from forgetting to subtract PaCO2/0.8. A true shunt would widen the gradient and respond poorly to oxygen, and these numbers show neither.
• C. The arithmetic is right but the conclusion is not: a diffusion defect widens the gradient, especially on exertion, whereas a normal gradient points to hypoventilation or low inspired oxygen.
• D. 25 mm Hg comes from subtracting PaCO2 without dividing by the respiratory quotient (0.8). The real gradient is normal, so there is no evidence of V/Q mismatch from aspiration.

Answer: C — Give 100% oxygen by non-rebreathing mask and obtain an arterial sample for CO-oximetry

Standard two-wavelength pulse oximeters cannot tell carboxyhemoglobin from oxyhemoglobin, so SpO2 reads falsely high in carbon monoxide poisoning. Smoke exposure plus headache and confusion makes CO poisoning likely: give the highest FiO2 available at once (100% oxygen shortens the COHb half-life from about 4-5 hours on room air to roughly 1-1.5 hours) and measure COHb by CO-oximetry. SpO2 cannot be used to titrate.

• A. A normal SpO2 means nothing here: the oximeter counts COHb as oxygenated hemoglobin and can hide severe CO poisoning.
• B. Titrating to SpO2 relies on the very number CO falsifies, and a low FiO2 slows CO elimination; this patient needs the highest FiO2 available.
• D. A chest film may help later with inhalation injury, but it does not diagnose CO poisoning, and delaying oxygen is harmful.

Answer: B — About 5.7 hours

One pound of liquid oxygen yields about 344 L of gaseous oxygen. 4 lb x 344 L/lb = 1,376 L, and 1,376 L / 4 L/min = 344 min, or about 5.7 hours. Convert weight to gas volume first, then divide by the flow; in practice the unit also vents some gas when idle, so real duration is a little shorter.

• A. 1.4 hours is the answer for 1 lb (344 L / 4 L/min); it ignores the 4-lb contents.
• C. 11.5 hours is the duration at 2 L/min, not at the prescribed 4 L/min.
• D. 14.3 hours uses the 860:1 liquid-to-gas expansion ratio as if it were liters of gas per pound; 860 applies per liter of liquid, not per pound.

Answer: B — Decrease the FiO2 and titrate to the unit's SpO2 target

Ventilation is acceptable for a newborn (pH 7.33, PaCO2 47), but a PaO2 of 92 mm Hg is above the usual 50-80 mm Hg target for a preterm infant. Excess oxygen in preterm infants is linked to retinopathy of prematurity and lung injury, so wean the FiO2 to the unit's SpO2 target (commonly about 90-95% in preterm infants) instead of leaving it high.

• A. More oxygen deepens the hyperoxia in an infant who is already above target.
• C. Switching to a hood at the same FiO2 changes the device, not the problem, which is too much oxygen.
• D. The infant is ventilating adequately and is over-oxygenated; nothing here indicates intubation.

Answer: A — Controlled breathing that starts at low lung volume and moves to mid and then high lung volume, moving mucus from small to larger airways before a huff

Autogenic drainage uses breathing at different lung volumes: an 'unstick' phase at low volume loosens peripheral secretions, a 'collect' phase at mid volume moves them into the middle airways, and an 'evacuate' phase at high volume brings them to the central airways, where a huff clears them. It needs no equipment but takes practice and is harder to teach than most techniques, so it suits older children and adults.

• B. Forceful coughing early in the session causes dynamic airway collapse in CF and moves little peripheral mucus; autogenic drainage holds the cough until secretions are central.
• C. Breathing out against a resistor is positive expiratory pressure (PEP) therapy, a different technique that needs a device.
• D. Forcing air out to residual volume collapses the small airways and traps mucus; autogenic drainage keeps exhalation active but unforced to avoid that collapse.

Answer: A — Decrease VT to about 330 mL (6 mL/kg PBW) and increase the rate to keep minute ventilation

Her predicted body weight is 45.5 + 2.3 x (64 - 60) = 54.7 kg, so 500 mL is about 9 mL/kg PBW, and a plateau pressure of 33 cm H2O breaks the ARDSNet limit of 30. Lung-protective ventilation sets VT at 6 mL/kg PBW (about 330 mL) and raises the rate (up to 35/min) to limit the rise in PaCO2. Her P/F ratio of 110 is moderate ARDS, so PEEP stays where the PEEP/FiO2 table puts it.

• B. Dropping PEEP lowers the plateau pressure only by derecruiting lung and will worsen an already low PaO2; at FiO2 0.60 the ARDSNet tables call for PEEP of 10 or more, not less.
• C. A bigger VT raises plateau pressure further and adds ventilator-induced lung injury; oxygenation in ARDS is improved with PEEP and FiO2, not larger breaths.
• D. More oxygen does not fix the injurious VT and plateau pressure, and an FiO2 of 1.0 is a last step after PEEP and lung protection are in place.