Final answer:
During a stress test, an increase in pulse rate from 76 to 84 should indicate distress in an adult patient.
Step-by-step explanation:
During a stress test, an increase in pulse rate from 76 to 84 should indicate to an EKG tech that an adult patient is experiencing distress. This is because an increase in heart rate may be a sign of the heart not providing sufficient oxygenated blood to the tissues. Other vital sign changes, such as a decrease in body temperature, an increase in blood pressure, or an increase in respiratory rate, would not necessarily indicate distress during a stress test.