Developing a consensus-based definition of out-of-hospital clinical deterioration: A Delphi study

Clinical deterioration is a time-critical medical emergency requiring rapid recognition and intervention. Deteriorating patients are seen across various healthcare settings, including the out-of-hospital (OOH) environment. OOH care is an evolving area of medicine where decisions are made regarding priority and timing of clinical interventions, ongoing management, and transport to appropriate care. To date, the literature lacks a standardised definition of OOH clinical deterioration.

The objective of this study was to create a consensus-based definition of OOH clinical deterioration informed by emergency medicine health professionals.

A Delphi study consisting three rounds was conducted electronically between June 2020 and January 2021. The expert panel consisted of 30 clinicians, including emergency physicians and paramedics.

A consensus-based definition of OOH clinical deterioration was identified as changes from a patient's baseline physiological status resulting in their condition worsening. These changes primarily take the form of measurable vital signs and assessable symptoms but should be evaluated in conjunction with the history of events and pertinent risk factors. Clinicians should be suspicious that a patient could deteriorate when changes occur in one or more of the following vital signs: respiratory rate, heart rate, blood pressure, Glasgow Coma Scale, oxygen saturation, electrocardiogram, and skin colour. Almost all participants (92%) indicated an early warning system would be helpful to assist timely recognition of deteriorating patients.

The creation of a consensus-based definition of OOH clinical deterioration can serve as a starting point for the development and validation of OOH-specific early warning systems. Moreover, a standardised definition allows meaningful comparisons to be made across health services and ensures consistency in future research. This study has shown recognition of OOH clinical deterioration to be a complex issue requiring further research. Improving our understanding of key factors contributing to deterioration can assist timely recognition and intervention, potentially reducing unnecessary morbidity and mortality.