What type of pressure waveform does Pressure Control (PC) ventilation exhibit?

• A. Triangular
• B. Square
• C. Sine
• D. Linear

Answer: (B)

In Pressure Control (PC) ventilation, the pressure delivered during each breath is maintained at a set level throughout the inspiratory phase, which creates a specific pressure waveform. The waveform is described as square because it rapidly rises to the preset pressure and then maintains that pressure until the ventilatory phase ends. This characteristic allows for consistent pressure delivery to the patient's airways regardless of changes in lung compliance or resistance. The square waveform is effective in ensuring that the set pressure is achieved swiftly and maintained throughout the inspiration, which is crucial for optimal ventilation, particularly in patients with various respiratory conditions.

In contrast, other waveform types differ in their pressure characteristics. For instance, a triangular waveform would show a gradual increase and decrease in pressure, while sine waveforms would illustrate a smooth oscillation, neither of which is applicable to the steady-state pressure control offered by PC ventilation. The linear waveform could suggest a rise and fall in pressure that doesn’t match the set requirements of PC mode, which prioritizes maintaining constant pressure. Thus, the square waveform accurately represents the essence of Pressure Control ventilation.