Which of the following is a common indicator for the need for supplemental oxygen?

Increased respiratory rate is a common indicator for the need for supplemental oxygen because it often signifies that the body is attempting to compensate for reduced oxygen availability. When a person's oxygen levels drop—due to conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, or other respiratory issues—the body responds by increasing the respiratory rate in an effort to take in more oxygen. This physiological reaction reflects the body's need for oxygen, making it a key sign that supplemental oxygen may be required to maintain adequate oxygenation and prevent hypoxia.

In contrast, a decreased heart rate is generally not associated with the immediate need for supplemental oxygen and can occur in various conditions, but is not a direct indicator of oxygen deficiency. Elevated blood pressure may indicate stress or other medical issues, but it does not specifically point to a need for oxygen. Regular oxygen saturation levels, by definition, indicate that the oxygen levels are stable and adequate, thus not warranting additional oxygen therapy. Therefore, the increased respiratory rate serves as a clear and significant indicator that can prompt the administration of supplemental oxygen.