NBRC Respiratory Therapist 4

Question 1

Which finding on a flow-volume loop is most consistent with a fixed upper airway obstruction?

Accepted Answer

Flattening of both the inspiratory and expiratory limbs

Answer

Fixed upper airway obstruction (e.g., tracheal stenosis) limits flow equally in both directions, producing a flattened plateau on both limbs.

Question 2

A patient with asthma presents to the ED with SpO2 88%, wheezing, and inability to complete sentences. After two doses of albuterol, there is minimal improvement. What medication should be added next?

Accepted Answer

Inhaled ipratropium and systemic magnesium sulfate

Answer

In severe acute asthma refractory to initial beta-agonist therapy, adding inhaled anticholinergics and IV magnesium sulfate provides additive bronchodilation.

Question 3

When using high-frequency oscillatory ventilation (HFOV), oxygenation is primarily controlled by adjusting:

Accepted Answer

Mean airway pressure (mPaw)

Answer

On HFOV, mean airway pressure determines lung recruitment and FRC, which is the primary determinant of oxygenation.

Question 4

A patient's capnography waveform shows an exponential decrease in end-tidal CO2 during CPR. What does this most likely indicate?

Accepted Answer

Esophageal intubation

Answer

A sudden, exponential drop in ETCO2 to near-zero values during CPR strongly suggests esophageal intubation, as no CO2 is produced in the GI tract.

Question 5

Which calculation correctly determines alveolar oxygen tension (PAO2) using the alveolar air equation?

Accepted Answer

PAO2 = (FiO2 × 713) - (PaCO2 / 0.8)

Answer

The alveolar air equation is PAO2 = (FiO2 × [PB - PH2O]) - (PaCO2/RQ), which at sea level simplifies to (FiO2 × 713) - (PaCO2/0.8).

NBRC - National Board for Respiratory Care Practice Test

NBRC - National Board for Respiratory Care Practice Test

NBRC Respiratory Therapist 4