Effects of Trigger Algorithms on Trigger Performance and Patient-Ventilator Synchrony.

Area of Science:

• Mechanical Ventilation
• Respiratory Mechanics
• Patient-Ventilator Interaction

Background:

• Patient-ventilator synchrony is crucial for effective mechanical ventilation.
• Conventional trigger algorithms can lead to delays and asynchronous events.
• Advanced algorithms aim to improve breath triggering and cycling.

Purpose of the Study:

• To compare the IntelliSync+ (IS+) inspiratory trigger algorithm against conventional flow and pressure triggers.
• To evaluate the performance of IntelliSync+ expiratory trigger (IS+exp) in pressure control continuous spontaneous ventilation (PC-CSV).
• To assess trigger delay and asynchronous events under various simulated lung conditions and with leaks.

Main Methods:

• Simulated lung models with normal, ARDS, and COPD mechanics at three severity levels.
• Ventilation modes included pressure control continuous mandatory ventilation and PC-CSV.
• Tested IntelliSync+ inspiratory trigger (IS+insp), flow trigger, and pressure trigger.
• Evaluated IntelliSync+ expiratory trigger (IS+exp) against standard cycling criteria in PC-CSV.
• Measurements included trigger delay time and asynchronous events, with and without a 50% leak.

Main Results:

• Pressure triggering failed to achieve three consecutive successful breaths in any condition.
• IS+insp demonstrated significantly shorter trigger delay times compared to flow triggers across most models (e.g., normal: 81 ms vs 99 ms).
• Ineffective efforts were significantly less frequent with IS+insp (1.5%) than with flow triggers (7.3%) without leaks.

Conclusions:

• IntelliSync+ inspiratory trigger (IS+insp) offers comparable trigger times and superior performance in reducing ineffective efforts versus flow triggers.
• The IntelliSync+ expiratory trigger (IS+exp) did not significantly impact cycling delay, showing high variability across conditions.
• IS+insp represents a potential improvement for patient-ventilator synchrony in specific ventilation settings.