Beyond Arterial Pressure: A Conceptual Model for Integrative Hemodynamic Assessment in Shock

Shock remains a major cause of morbidity and mortality in critical care despite substantial advances in monitoring and resuscitation. Persistent reliance on arterial pressure–centered assessment limits early detection of tissue hypoperfusion, as compensatory mechanisms may preserve macrocirculatory variables while cellular hypoxia and metabolic failure progress. This pressure–perfusion dissociation contributes to delayed diagnosis, late intervention, and unfavorable outcomes, highlighting the need for a pathophysiological coherent approach to shock evaluation. This article develops a theory-driven conceptual framework for integrative hemodynamic assessment grounded in pathophysiological reasoning rather than outcome-based metrics. Drawing on established evidence related to microcirculatory dysfunction, venous congestion, metabolic failure, and loss of hemodynamic coherence, shock is conceptualized as a dynamic, self-reinforcing system. The framework is organized around three interdependent hemodynamic domains—Perfusion, Flow, and Venous drainage—whose interaction defines the integrative hemodynamic state. The model is non-prescriptive and does not introduce numerical scores, clinical protocols, or therapeutic algorithms.The proposed framework enables phenotype-oriented interpretation of shock by identifying the dominant axis of circulatory failure, including impaired forward flow, pathological venous congestion, microcirculatory-metabolic decoupling, or mixed patterns. By shifting emphasis from arterial pressure toward restoration of perfusion coherence, this framework provides a structured foundation for mechanism-aware clinical reasoning and future perfusion-oriented research, while acknowledging the need for prospective validation.