A respiratory therapist notes a prolonged inspiratory time and variable cycling to exhalation for a patient receiving PS ventilation. What should the therapist check next?

In the context of a patient experiencing prolonged inspiratory time and variable exhalation cycling during pressure support (PS) ventilation, the most pertinent factor to check next is the integrity of the endotracheal tube cuff.

A defective cuff can lead to inadequate pressure support as it may not maintain a proper seal within the airway, potentially allowing air to escape and affecting the delivery of mechanical ventilation. If the cuff is compromised, it can result in an ineffective breath or prolonged inspiratory times, as the ventilator attempts to maintain the set pressure without effectively delivering it to the lungs.

While evaluating for other factors such as right mainstem intubation, auto-PEEP, and mucus plugging may also be important in different contexts, they do not directly relate to the immediate concern of prolonged inspiratory time and variable cycling to exhalation as decisively as checking the endotracheal tube cuff. Thus, ensuring that the cuff is intact and functioning correctly is crucial for optimal ventilation and patient stability.