Standardising Terminology, Classification, Diagnostic Recognition and Reporting of Patient-Ventilator Interactions: Protocol for an International Delphi Consensus Study (INTERACT)

Introduction:

Optimal patient-ventilator interaction (PVI) is a state of harmony in which ventilatory support is aligned with the patient's neural respiratory drive and breathing pattern, thereby achieving the core goals of mechanical ventilation, including comfort, safety, and timely liberation from the ventilator. Disruption of this harmony results in abnormal PVI patterns, which have been associated with increased work of breathing (WOB), a higher risk of ventilator-induced lung injury (VILI), greater requirement for sedation and neuromuscular blockade, and prolonged duration of mechanical ventilation and intensive care unit (ICU) stay.

Achieving and maintaining optimal PVI requires clinicians to be familiar with its terminology, understand the underlying physiological mechanisms, and recognise, interpret, prevent, and manage abnormal interactions at the bedside. However, PVI terminology remains highly inconsistent. 'Early triggering', 'reverse triggering', and 'neural or ventilator-induced entrainment', are often used interchangeably, while 'double triggering' and 'double cycling' are inconsistently defined and applied. Descriptors, including 'starvation', 'flow mismatch', and 'under-assistance' are variably applied, and terms including 'missed efforts', 'ineffective triggering', 'ineffective efforts', and 'failed trigger' are frequently used to describe the same abnormality. In parallel, broader labels such as dyssynchrony, asynchrony, and PVI patterns coexist without a standardised conceptual hierarchy. This inconsistency reflects a fundamental lack of consensus on how PVI phenomena should be defined and classified.

This lack of standardisation creates confusion and hinders accurate recognition, education, and communication, limits comparability in reporting across studies, and impedes the development of automated detection systems. Although recent initiatives have moved toward greater standardisation, adoption remains incomplete and legacy terminology continues to be widely used.

To address these challenges, we plan an international Delphi consensus, The INTERACT (International Consensus on Patient-Ventilator Interaction Terminology, Classification, Diagnostic Recognition and Reporting) study, to develop a standardised framework for PVI. Specifically, we aim to harmonise terminology, establish a clear and clinically meaningful classification of PVI patterns, define the key diagnostic features and minimal monitoring requirements for their recognition, and propose standardised reporting recommendations for both research and clinical practice. By building expert consensus across disciplines and regions, this initiative seeks to create a shared and practical foundation to improve communication, education, research comparability, and ultimately patient care.