Successive peak flow measurements made with a peak flowmeter on a subject previously diagnosed as having asthma yield the following results:

Which of the following is the best explanation for these?

During exercise, a subject's oxygen consumption increases out of proportion to his cardiac output. This is due to an increase in

In which of the following patients would an end-tidal CO2 most likely produce values that are inconsistent with PaCO2?

A patient is performing a flow-volume loop. A pulmonary function technologist observes equal decreases in expiratory and inspiratory flows resulting in plateaus. Patient effort is satisfactory, and he follows instructions well. The technologist should expect the patient to have a

A pulmonary function technologist is reviewing an asthma action plan. The patient takes a low-dose inhaled corticosteroid and a long-acting beta2-agonist twice daily. The patient's personal best peak flow is 600 L/min.
Which of the following instructions should be given to the patient when the peak flow drops to 500 L/min?