In what type of respiratory support does pressure support ventilation (PSV) commonly operate?

• A. Every breath is fully assisted
• B. Spontaneous breaths are supported
• C. No baseline pressure is established
• D. Only during general anesthesia

Answer: (B)

Pressure support ventilation (PSV) operates on the principle of providing assistance during spontaneous breathing efforts by the patient. In this mode, the patient triggers their breaths, and the ventilator delivers a preset level of pressure to support these breaths. This means that the patient maintains control over their breathing rate and depth while benefiting from the ventilator's assistance, which makes it particularly useful for individuals who can initiate breaths but require additional support to overcome the work of breathing.

The other options describe scenarios that do not align with PSV's operation. For instance, fully assisting every breath would be characteristic of controlled modes of ventilation, where the machine takes complete control. The absence of a baseline pressure does not apply here, as PSV relies on a preset pressure level to support breaths. Additionally, while PSV can be used in various contexts, including during weaning from mechanical ventilation, it is not limited to situations involving general anesthesia, where other ventilation modes would be more appropriate.