Patient ventilator asynchrony in critically ill adults: frequency and types

Area of Science:

• Critical Care Medicine
• Respiratory Therapy
• Biomedical Engineering

Background:

• Patient ventilator asynchrony (PVA) is a frequent complication in mechanical ventilation.
• PVA is linked to increased patient discomfort, distress, and poorer clinical outcomes, including prolonged ventilation and hospital stays.
• Limited understanding exists regarding the specific types and prevalence of PVA.

Purpose of the Study:

• To investigate the types and frequency of patient ventilator asynchrony (PVA).
• To analyze waveform data to identify and characterize different PVA events.
• To explore the clinical implications of newly identified PVA patterns.

Main Methods:

• Collected pressure-time and flow-time waveform data from 27 ICU patients.
• Utilized the Noninvasive Cardiac Output monitor for data acquisition.
• Performed blinded waveform analysis to identify PVA events.

Main Results:

• Patient ventilator asynchrony (PVA) was observed across all ventilation phases and modes.
• The most prevalent type of PVA was ineffective trigger, where patient effort fails to initiate ventilation.
• While 23% of breaths were asynchronous, 93% of patients experienced at least one PVA event, with 77% experiencing multiple types.

Conclusions:

• Patient ventilator asynchrony (PVA) is highly prevalent and diverse, with ineffective trigger being the most common form.
• The study identified novel waveforms suggesting a broader spectrum of PVA than previously recognized.
• Newly described PVAs, especially combined events within a single breath, may indicate significant patient distress and require clinical attention.