The proper application of PSV requires which of the following?

• A. All breathing effort is directed by the machine
• B. Patient-initiated breaths should be ignored
• C. Consistent spontaneous respiratory pattern from the patient
• D. Setting high tidal volumes for the patient

Answer: (C)

The proper application of Pressure Support Ventilation (PSV) requires a consistent spontaneous respiratory pattern from the patient. In PSV, the ventilator assists the patient's spontaneous breaths by providing a set pressure to augment the tidal volume based on the patient's own efforts. This means that the patient must be capable of initiating breaths and demonstrating a regular respiratory pattern for PSV to be effective.

When patients have a predictable breathing pattern, the ventilator can effectively assess when to provide support, optimizing oxygenation and ventilation according to the patient's needs. If a patient's respiratory efforts are inconsistent, the benefits of PSV can diminish, potentially leading to inadequate support or over-assistance.

In contrast, if all breathing effort were directed by the machine, that would not align with the fundamental goal of PSV, which is to provide support for the patient's own initiated breaths. Ignoring patient-initiated breaths would contradict the ventilatory strategy of ensuring that the patient maintains some control over their own ventilatory needs. Similarly, high tidal volumes are not a requirement in PSV and can potentially lead to complications, especially if the patient cannot handle such volumes comfortably. Hence, the patient's ability to maintain a consistent spontaneous respiratory pattern is essential for the effective use of PSV.