What does pressure support (PS) do in the context of ventilation?

• A. It assists spontaneous breaths to reduce work of breathing
• B. It provides fixed volume breaths
• C. It delivers only mandatory breaths without support
• D. It completely replaces the need for spontaneous effort

Answer: (A)

Pressure support (PS) is a mode of ventilation designed to assist patients who are breathing spontaneously but may require additional help to manage their ventilatory workload. When a patient initiates a breath, the ventilator delivers a preset level of pressure to support that breath. This assistance helps to reduce the work of breathing, making it easier for the patient to inhale and exhale effectively.

In this mode, the patient still retains the ability to control their respiratory rate and depth, making it a more comfortable and physiologically appropriate choice for those who can initiate breaths independently. The pressure support adjusts to the effort of the patient, providing enhanced comfort and aiding in weaning from mechanical ventilation.

This contrasts with the other options: fixed volume breaths imply a control that doesn't allow for the spontaneous adjustments necessary for a patient's varying needs. Delivering only mandatory breaths without support eliminates the crucial element of spontaneous effort that PS enhances. Lastly, completely replacing the need for spontaneous effort would negate the purpose of pressure support, which is specifically to facilitate and augment, rather than entirely take over, a patient’s ability to breathe independently.