What best describes the primary function of PC ventilation?

• A. A combination of pressure and flow control
• B. Strictly mechanical breaths with no patient interaction
• C. Pressure control that varies with user input
• D. A single pressure setting without variability

Answer: (A)

The primary function of PC (Pressure Control) ventilation is best described as a combination of pressure and flow control. In this mode, the ventilator delivers breaths at a predetermined pressure level, allowing for the tidal volume to vary based on the patient's compliance and resistance. This flexibility means that the ventilator can adapt to the patient's needs, optimizing the flow rates during inhalation while maintaining the selected pressure. By using pressure control in conjunction with flow adjustment, the patient's breathing mechanics are more effectively supported, allowing for better ventilation outcomes and comfort.

This approach enhances patient-ventilator synchronization, particularly in patients who may have variable lung compliance or resistance. The use of pressure control also ensures that the peak inspiratory pressure does not exceed a set limit, which can help reduce the risk of barotrauma. Thus, the correct answer reflects the complex interaction and adaptability inherent in PC ventilation, rather than a rigid or singular approach to respiratory support.