RRT RRT 3 — Questions and Answers
Question 1: Which pulmonary function test finding is most consistent with obstructive lung disease?
- Reduced TLC with normal FEV1/FVC
- FEV1/FVC ratio less than 0.70 (Correct answer)
- Increased FVC with normal FEV1
- Reduced DLCO with normal FEV1/FVC
Correct answer: FEV1/FVC ratio less than 0.70
An FEV1/FVC ratio below 0.70 is the hallmark spirometric criterion for airflow obstruction.
Question 2: Which medication is most appropriate for treating a patient experiencing an acute severe asthma attack unresponsive to inhaled albuterol?
- Oral prednisone alone
- Intravenous magnesium sulfate (Correct answer)
- Inhaled salmeterol
- Subcutaneous epinephrine only
Correct answer: Intravenous magnesium sulfate
IV magnesium sulfate causes bronchial smooth muscle relaxation and is used for severe refractory asthma.
Question 3: When calculating the alveolar-arterial (A-a) oxygen gradient, which formula is used to find PAO2?
- PAO2 = FiO2 × PB
- PAO2 = FiO2 (PB - PH2O) - PaCO2/RQ (Correct answer)
- PAO2 = PaO2 + PaCO2
- PAO2 = PaO2 / FiO2
Correct answer: PAO2 = FiO2 (PB - PH2O) - PaCO2/RQ
The alveolar gas equation: PAO2 = FiO2(PB − 47) − PaCO2/0.8 is used to calculate alveolar oxygen tension.
Question 4: Which of the following best describes the Fick principle as applied to cardiac output measurement?
- CO = stroke volume / heart rate
- CO = O2 consumption / (CaO2 - CvO2) (Correct answer)
- CO = mean arterial pressure / SVR
- CO = tidal volume × respiratory rate
Correct answer: CO = O2 consumption / (CaO2 - CvO2)
The Fick principle states cardiac output equals oxygen consumption divided by the arteriovenous oxygen content difference.
Question 5: A patient with neuromuscular disease shows a maximum inspiratory pressure (MIP) of -18 cmH2O. What does this suggest?
- Excellent respiratory muscle strength
- Mild respiratory muscle weakness only
- Significant respiratory muscle weakness requiring monitoring for ventilatory failure (Correct answer)
- Normal respiratory function
Correct answer: Significant respiratory muscle weakness requiring monitoring for ventilatory failure
MIP less negative than -20 cmH2O indicates severe inspiratory muscle weakness and risk of ventilatory failure.
Question 6: Which oxygen delivery device provides the most precise and consistent FiO2?
- Simple face mask
- Nasal cannula
- Venturi mask (Correct answer)
- Non-rebreather mask
Correct answer: Venturi mask
The Venturi mask uses the Bernoulli principle to entrain a fixed ratio of room air, delivering precise FiO2 regardless of flow rate.
Question 7: A newborn has Apgar scores of 3 at 1 minute and 5 at 5 minutes. The FIRST priority intervention is:
- Administer epinephrine
- Establish vascular access
- Stimulate and open the airway with positive pressure ventilation if needed (Correct answer)
- Perform chest compressions immediately
Correct answer: Stimulate and open the airway with positive pressure ventilation if needed
Neonatal resuscitation begins with warmth, stimulation, and airway management; PPV is initiated if HR <100 or inadequate breathing.
RRT RRT 3
Which pulmonary function test finding is most consistent with obstructive lung disease?