Final answer:
The technician should ask the patient to take slower and deeper breaths if hyperventilating during an exercise stress test, as this will help restore normal breathing patterns and ensure accurate test results.
Step-by-step explanation:
During an exercise stress test, if a technician notices that the patient appears to be hyperventilating, the appropriate action would be to ask the patient to take slower and deeper breaths. Hyperventilation during an exercise stress test is not desired, as it can lead to abnormally low blood carbon dioxide levels and a high (alkaline) blood pH, which does not accurately reflect the patient's normal physiologic response to exercise. Hyperpnea, which is an increased depth and rate of ventilation to meet an increase in oxygen demand, occurs naturally during exercise without significantly altering blood oxygen or carbon dioxide levels. If the patient cannot control their breathing, the test might need to be paused until their breathing returns to normal, although administering oxygen usually is not necessary unless the patient is showing signs of hypoxemia.