What two triggers can initiate inspiration in patient-triggered assisted ventilation?

• A. Pressure and time
• B. Volume and flow
• C. Time and patient triggered
• D. Patient effort and ventilator settings

Answer: (A)

In patient-triggered assisted ventilation, inspiration can be initiated by two fundamental triggers: pressure and time. When a patient initiates a breath, the ventilator detects either a specific pressure threshold that the patient generates (pressure trigger) or a preset time interval during which the ventilator delivers a breath regardless of patient effort (time trigger).

The pressure trigger allows the patient to take a breath when they generate a sufficient negative pressure, thus allowing for more patient autonomy and involvement in their ventilation process. On the other hand, the time trigger ensures that breaths are delivered at regular intervals, even if the patient does not initiate a breath on their own. This combination of triggers is crucial for ensuring adequate ventilation and supporting patients who may have varying levels of respiratory drive.

In contrast, options that reference volume and flow, or patient effort combined with ventilator settings, do not accurately describe the primary triggers in this context. Although these factors affect ventilation, they do not directly initiate the inspiration phase as defined by the pressure and time triggers in patient-triggered modes.