Basic and Clinical Sciences Examination (BCSE) Practice Exam 2025 – Comprehensive All-in-One Guide for Exam Success

Ventilatory respiratory failure occurs when the lungs cannot adequately ventilate, leading to insufficient oxygen intake and carbon dioxide removal. In this context, chest wall deformities significantly impact the mechanics of breathing, often resulting in inadequate ventilation.

Conditions such as kyphoscoliosis, severe obesity (obesity hypoventilation syndrome), and thoracic deformities can restrict chest expansion and impair the effectiveness of the respiratory muscles. This results in reduced tidal volume and vital capacity, which can lead to respiratory failure. The inability to fully expand the lungs compromises the ability to oxygenate blood and remove carbon dioxide, thereby causing ventilatory respiratory failure.

While asthma can cause an obstruction to airflow and may lead to respiratory difficulties, it primarily affects the air passages rather than the mechanics of ventilation itself, often resulting in an obstructive pattern rather than ventilatory failure. Similarly, high altitude can lead to hypoxia due to lower oxygen levels in the environment but does not typically result in a mechanical failure to ventilate. Increased physical activity generally enhances respiratory function and ventilation, as the body adapts to higher oxygen demands, which does not lead to respiratory failure in healthy individuals.