What is the consequence of excessive dead space in ventilation?

Excessive dead space in ventilation leads to an increased work of breathing because it means that a portion of the air that is inhaled does not participate in gas exchange. Dead space refers to the parts of the respiratory system where air is present but where no gas exchange occurs, such as the trachea and bronchi. When there's an increase in dead space, the body's work to ventilate effectively increases, as the volume of air needed to achieve effective gas exchange becomes greater. This can lead to hypoxemia and inadequate ventilation, prompting the respiratory muscles to exert more effort to maintain proper oxygen and carbon dioxide levels in the blood.

The other options do not correctly summarize the implications of excessive dead space. Improved oxygenation is unlikely to occur since the presence of increased dead space can result in less effective transfer of oxygen. The need for ventilatory support would typically increase in the presence of excessive dead space due to the challenge of maintaining adequate ventilation. Lower peak inspiratory pressures are also not a direct consequence since the pressures may actually increase in an attempt to achieve adequate ventilation against the additional dead space. Therefore, the consequence aligns with the increased work of breathing due to the ineffective portions of inhaled air not contributing to gas exchange.