What is trigger sensitivity in mechanical ventilation?

Trigger sensitivity in mechanical ventilation refers to the threshold pressure that the ventilator detects from the patient's efforts to breathe. It determines how easily the ventilator will respond to spontaneous breaths initiated by the patient.

When set appropriately, the trigger sensitivity is usually adjusted within a range between -1 and -3 cm H2O. This means that only a minor change in pressure is required from the patient for the ventilator to recognize an attempt to breathe and respond accordingly, initiating ventilation. If the sensitivity is set too high (more negative), it may lead to insufficient support for the patient and could cause discomfort or delay in the ventilator response; if set too low (less negative), it may lead to excessive breaths from the ventilator, which can also be detrimental.

The other options do not accurately describe trigger sensitivity. The highest pressure required to initiate breathing focuses more on pressure limits rather than sensitivity. The speed at which breaths are delivered relates to the ventilatory rate and flow, and a measure of patient comfort is more appropriately tied to factors like tidal volume and pressure settings rather than sensitivity itself.