In which of the following scenarios is pressure support ventilation NOT appropriate?

• A. Patients with a consistent and reliable ventilatory drive
• B. Patients with periods of inconsistent or unreliable ventilatory drive
• C. Patients requiring gradual weaning from mechanical ventilation
• D. Patients with a stable respiratory pattern

Answer: (B)

Pressure support ventilation (PSV) is a mode designed to assist patients who have some ability to initiate their breaths while reducing the work of breathing. This mode is particularly beneficial for patients who demonstrate a reliable ventilatory drive, allowing them to receive support during inhalation while still maintaining some control over their breathing pattern.

In scenarios where a patient has an inconsistent or unreliable ventilatory drive, PSV is less suitable. This is because patients who cannot consistently initiate breaths may not adequately trigger the ventilator, leading to ineffective ventilation and insufficient respiratory support. An unreliable ventilatory drive can result in periods of respiratory failure or hypoventilation, making it vital for these patients to be placed on modes of ventilation that provide more consistent and guaranteed support, such as assist-control ventilation or continuous mandatory ventilation.

Conversely, scenarios like having a consistent and reliable ventilatory drive, needing gradual weaning from mechanical ventilation, or having a stable respiratory pattern are all situations where PSV is appropriate. Each of these conditions leverages the benefits of PSV, allowing for effective respiratory support while still enabling patients to participate in their ventilation efforts.