Which of the following is sometimes included in a vital signs assessment?

• A. Temperature
• B. Pulse
• C. Blood pressure
• D. Oxygen saturation

Answer: (D)

Oxygen saturation is included because it shows how well oxygen is being carried to the body's tissues, giving a quick picture of respiratory and circulatory status alongside temperature, pulse, and blood pressure. It’s measured with a pulse oximeter, a noninvasive device that sits on a finger (or earlobe) and estimates the percent of hemoglobin bound with oxygen. Normal readings are typically 95–100%; lower numbers can indicate hypoxemia and may require intervention or closer monitoring. Readings can be affected by factors like poor peripheral perfusion, cold fingers, movement, nail polish, or external carbon monoxide. This measure is especially useful in patients with respiratory or heart conditions, during anesthesia or post-op recovery, in acute care, or when someone is on oxygen therapy. In many CNA assessments, it’s checked in addition to the standard vital signs and reported if it’s outside the expected range.