RRT Respiratory Therapy 5 — Questions and Answers
Question 1: A patient is prescribed heliox (70% He / 30% O2) for severe upper airway obstruction. The PRIMARY benefit of helium in this mixture is:
- Increased oxygen-carrying capacity
- Reduced gas density improving flow through narrow airways (Correct answer)
- Bronchodilation of small airways
- Enhanced mucociliary clearance
Correct answer: Reduced gas density improving flow through narrow airways
Helium's low density reduces turbulent flow resistance in obstructed upper airways, improving gas delivery until definitive treatment.
Question 2: During neonatal resuscitation, what initial FiO2 is recommended for term infants?
- 1.0 (100% oxygen)
- 0.21 (room air) (Correct answer)
- 0.40
- 0.60
Correct answer: 0.21 (room air)
Current NRP guidelines recommend starting resuscitation of term neonates with room air (FiO2 0.21) and titrating based on pre-ductal SpO2 targets.
Question 3: Which spirometric pattern is characteristic of a patient with pulmonary fibrosis?
- Reduced FEV1/FVC ratio with increased TLC
- Normal FEV1/FVC ratio with reduced TLC and FVC (Correct answer)
- Reduced FEV1 with air trapping
- Normal FEV1 and FVC with reduced DLCO only
Correct answer: Normal FEV1/FVC ratio with reduced TLC and FVC
Restrictive diseases like pulmonary fibrosis reduce all lung volumes (TLC, FVC) while preserving or increasing the FEV1/FVC ratio.
Question 4: A patient receiving aerosolized pentamidine for PCP prophylaxis should be treated in:
- Standard patient room with the door closed
- A negative-pressure isolation room (Correct answer)
- A positive-pressure room to protect the patient
- Any location with adequate hallway ventilation
Correct answer: A negative-pressure isolation room
Aerosolized pentamidine can activate latent TB; treatments should occur in negative-pressure rooms to prevent environmental contamination.
Question 5: Plateau pressure minus total PEEP (intrinsic + extrinsic) equals:
- Peak airway pressure
- Driving pressure (Correct answer)
- Mean airway pressure
- Compliance pressure
Correct answer: Driving pressure
Driving pressure (ΔP) = Plateau pressure − total PEEP, reflecting the stress applied to the respiratory system with each breath; ΔP > 15 cmH2O is associated with increased ARDS mortality.
Question 6: A patient in the ICU has a pulmonary capillary wedge pressure (PCWP) of 22 mmHg and bilateral infiltrates. This presentation is MOST consistent with:
- ARDS (non-cardiogenic pulmonary edema)
- Cardiogenic pulmonary edema (Correct answer)
- Pulmonary embolism
- Pneumonia without heart failure
Correct answer: Cardiogenic pulmonary edema
PCWP > 18 mmHg with bilateral infiltrates indicates cardiogenic (hydrostatic) pulmonary edema, distinguishing it from ARDS (PCWP ≤ 18 mmHg).
Question 7: Which oxygen delivery device provides the MOST precise and consistent FiO2 regardless of the patient's breathing pattern?
- Simple mask
- Nasal cannula
- Venturi mask (Correct answer)
- Partial rebreather mask
Correct answer: Venturi mask
The Venturi (air-entrainment) mask uses fixed jet orifices to entrain a precise air-to-oxygen ratio, delivering consistent FiO2 independent of inspiratory flow.
RRT Respiratory Therapy 5
A patient is prescribed heliox (70% He / 30% O2) for severe upper airway obstruction.
The PRIMARY benefit of helium in this mixture is: