Which metric is used to assess a patient’s respiratory rate, and what is its normal adult resting range?

• A. Tidal volume measured per breath; 400–600 mL.
• B. Breathing rate per minute; 12–20 breaths per minute.
• C. Oxygen saturation percentage.
• D. Respiratory rate measured per hour.

Answer: (B)

Respiratory rate is the count of breaths per unit time, typically per minute, and that frequency is what clinicians monitor to assess breathing at rest. The normal resting range for an adult is about 12 to 20 breaths per minute. The other items measure different things: tidal volume is the amount of air moved per breath, not how often breaths occur; oxygen saturation reflects how much hemoglobin is bound with oxygen, not the rate; and counting per hour isn’t the standard way to evaluate resting respiration.