Which of the following is a vital sign that should be assessed?

Respiratory rate is considered a vital sign because it reflects the number of breaths a person takes per minute and provides essential information about their respiratory function and overall physiological state. It helps in evaluating a patient’s oxygenation and can indicate potential respiratory distress or failure. Monitoring the respiratory rate is crucial in emergency situations, as changes can signal deteriorating conditions that require immediate intervention.

While skin color and capillary refill time are important assessments that can indicate circulation and perfusion, they are not classified as vital signs in the same sense as respiratory rate, heart rate, blood pressure, and temperature. Blood viscosity, on the other hand, is not typically measured in acute care settings as a vital sign, though it can have an impact on overall health and complications. Thus, respiratory rate is essential in understanding a patient's immediate status and is routinely monitored in clinical and emergency settings.