Which type of breath delivery controls the timing and tidal volume by the ventilator?

• A. Spontaneous breaths
• B. Mandatory breaths
• C. Assisted breaths
• D. Pressure breaths

Answer: (B)

Mandatory breaths are characterized by the ventilator controlling both the timing and tidal volume, ensuring that each breath delivered meets preset parameters. In this mode, regardless of the patient's effort, the ventilator imposes a specific breath rate and volume, providing consistent mechanical ventilation that is particularly beneficial for patients who cannot adequately ventilate themselves due to respiratory failure or fatigue. This method is crucial in maintaining adequate gas exchange and ensuring that patients receive the necessary ventilation support without relying on their respiratory drive, which may be impaired.

In contrast, spontaneous breaths rely on the patient's effort, where they can initiate breaths at their own pace, and the ventilator assists only when needed. Assisted breaths allow for patient-triggered inspiration but are not as controlled as mandatory breaths, as the volume may vary depending on the patient’s effort. Pressure breaths refer to modes where the ventilator delivers a breath at a set pressure rather than a specific volume, which can vary based on lung compliance and resistance. Thus, mandatory breaths are essential in settings where a controlled and consistent ventilation strategy is required.