What is the normal deadspace (Vd/Vt) percentage?

The normal dead space percentage, represented as Vd/Vt, is typically considered to be within the range of 10% to 20%. Therefore, the correct choice would be found in that range. Dead space refers to the portion of each breath that does not participate in gas exchange, either because it is ventilated but not perfused or because it is located in the conducting airways where no gas exchange occurs.

In general, a Vd/Vt ratio that exceeds 20% can indicate various pathological conditions affecting the lungs, such as pulmonary embolism, chronic obstructive pulmonary disease (COPD), or other forms of lung impairment. Values above this threshold typically correspond with significant ventilation-perfusion mismatch or reduced alveolar-capillary surface area available for gas exchange.

Understanding the normal range for deadspace is crucial for diagnosing lung conditions and assessing a patient's ventilatory status. Thus, knowing that the normal deadspace percentage is not significantly high reinforces the importance of maintaining efficient ventilation to ensure adequate oxygenation and carbon dioxide elimination.