Abstract
BACKGROUND: An increasing proportion of critically ill patients receive prolonged, high-acuity care in the emergency department (ED) before admission to the intensive care unit. Despite its clinical relevance, this early phase of care remains poorly characterized and difficult to capture using existing metrics. MAIN BODY: This Perspective argues that this early phase of critical illness represents a distinct but underrecognized component of the critical care continuum, commonly referred to as emergency critical care (ECC). Rather than being defined by location or specialty, ECC is characterized by time-critical decision-making, dynamic trajectory, and evolving care demands. A major challenge in studying this phase is its limited measurability within current frameworks. We therefore propose a pragmatic conceptualization of ECC based on three complementary dimensions: disease severity, clinical care intensity, and therapeutic organ support. Together, these dimensions describe key aspects of early critical illness and provide a pragmatic basis for translating ECC dimensions into observable clinical and administrative variables suitable for research, governance, and system evaluation without imposing rigid definitions or thresholds. CONCLUSION: Conceptualizing ECC along clinically meaningful and observable dimensions offers a practical way to improve its visibility in research and system evaluation. Recognizing ECC as a spectrum of critical care delivery rather than a binary state may provide a pragmatic basis for describing and studying early critical illness.