Which factor is recognized as a cause of increased dead space in respiratory therapy?

Increased dead space in the lungs refers to areas where ventilation occurs without corresponding perfusion, meaning that air reaches the alveoli but does not participate in gas exchange. Pulmonary embolism is recognized as a significant cause of increased dead space because it creates an obstruction in the pulmonary arteries, which prevents blood flow to portions of the lung. This leads to ventilation being wasted, as the air in affected alveoli cannot engage in gas exchange, resulting in an increase in physiological dead space.

When a pulmonary embolism occurs, it can result in substantial areas of the lung being ventilated but not perfused, significantly affecting the efficiency of gas exchange. This is critical in respiratory therapy, as it influences the management and treatment of patients with such conditions, emphasizing the importance of effective perfusion in addition to ventilation for optimal respiratory function. In contrast, chronic bronchitis, pneumothorax, and asthma primarily affect airflow and airway resistance rather than directly increasing dead space through mechanisms like obstruction of perfusion.