Which of the following can cause a low pressure alarm in a mechanical ventilator?

A low pressure alarm in a mechanical ventilator typically indicates that the pressure within the ventilatory system is lower than expected. This scenario can often arise from a leak in the ventilator circuit. When there is a leak, the ventilator is unable to maintain the required pressure to deliver the set tidal volume to the patient, thus triggering the low pressure alarm to alert the clinical staff to investigate the issue and ensure patient safety.

Additionally, while obstructions or other factors like pneumothorax can affect ventilation, they generally lead to elevated pressure rather than a drop in pressure. Therefore, instances like patient obstruction or secretions in the tubing can cause other alarms, but would not typically result in low pressure alarm conditions. Understanding the specific causes of ventilator alarms is crucial for effective patient management and intervention during mechanical ventilation.