Which of the following is the most accurate description of respiratory failure?

Respiratory failure is defined as a condition where the respiratory system fails to provide adequate gas exchange, leading to an inability to meet the metabolic needs of the body. This encompasses both the failure to oxygenate the blood adequately and the failure to remove carbon dioxide. The key aspect of respiratory failure is that it affects the balance of oxygen and carbon dioxide, which are critical for cellular metabolism and function.

When the description highlights "inadequate gas exchange," it points to the underlying problem of either hypoxemia (low oxygen levels) or hypercapnia (elevated carbon dioxide levels), or both. This definition encompasses a broader range of scenarios than just the absence of ventilation or acute episodes of hypoxemia, thereby capturing the complexity of respiratory failure as it relates to the body's overall metabolic demands.

In contrast, focusing solely on the absence of ventilation would not encompass cases where there is some level of ventilation, yet gas exchange remains inadequate. Similarly, while airway obstruction can lead to episodes of hypoxemia, it does not address the complete failure of gas exchange, which is central to the concept of respiratory failure. Thus, the correct choice presents the most comprehensive and clinically relevant definition.