Final answer:
The false statement about the use of an inspiratory pause is that it has not been shown to increase the effectiveness of bronchodilator therapy. An inspiratory pause can be useful in ARDS patients, for chest radiograph clarity, and it does increase mean airway pressure.
Step-by-step explanation:
You asked which statement is NOT true regarding the use of an inspiratory pause during mechanical ventilation. The answer is that it has not been shown to increase the effectiveness of bronchodilator therapy (option c). An inspiratory pause may indeed be useful in ARDS patients to improve oxygenation and allow for better distribution of air in the lungs, and during a chest radiograph to improve image clarity. Additionally, an inspiratory pause will increase the mean airway pressure.
Regarding the mechanics of breathing, when the diaphragm moves downwards during inspiration, it creates a partial vacuum, which reduces the pressure in the thoracic cavity, allowing outside air to flow into the lungs. Likewise, forced breathing during exercise involves contraction of additional accessory muscles to further increase lung volume.
In situations where there is increased airway resistance, such as an allergic reaction causing swelling in the airways, this would indeed increase resistance of the respiratory system, making it more difficult to breathe.