Certified Respiratory Therapist Practice Exam

Which patient likely has a ventilatory limitation to exercise based on a cardiopulmonary exercise test?

1. Patient B

2. Patient C

3. Patient D

4. Patient A

The correct answer is: Patient D

A patient who demonstrates ventilatory limitations during exercise likely exhibits a reduced maximal ventilation relative to their exercise capacity on a cardiopulmonary exercise test. This can be characterized by an inability to adequately increase the breathing rate or tidal volume in response to the metabolic demands of exercise, leading to early fatigue and a lower peak exercise performance. In particular, certain key indicators might suggest ventilatory limitation, such as a significant increase in respiratory rate without a proportional increase in tidal volume, a reduced ventilatory reserve, or a marked increase in the dead space to tidal volume ratio. If these variables show that the patient is unable to meet the ventilatory demands of increased physical activity, it points to ventilatory limitation. The conclusion that Patient C exhibits this limitation reflects specific patterns and outcomes from the exercise test that suggest their respiratory system is unable to adequately support the metabolic needs during increased exertion. In contrast, other patients might demonstrate more optimal responses that indicate either cardiac limitations or better ventilatory efficiency, allowing them to sustain higher levels of exercise without early onset of breathlessness or fatigue. The particulars that highlight Patient C’s deficiencies in ventilatory response further affirm the selection of this answer.