Vasoplegic Shock beyond Traditional Concepts: A Narrative Review

Vasoplegic shock is a frequent and life-threatening manifestation of critical illness, traditionally defined by hypotension due to low systemic vascular resistance (SVR) in the presence of preserved or increased cardiac output (CO).This hemodynamic definition, however, inadequately reflects the complex and heterogeneous biological processes underlying vasoplegia.Increasing evidence indicates that vasoplegic shock represents a spectrum of vascular failure syndromes characterized by endothelial dysfunction, vascular smooth muscle hyporesponsiveness, neurohormonal depletion, and microcirculatory uncoupling, rather than a single uniform entity.This narrative review reexamines vasoplegic shock beyond conventional paradigms, integrating contemporary insights into pathophysiology, bedside clinical phenotyping, and mechanismbased therapeutic strategies.Key biological drivers-including nitric oxide overproduction, endothelial glycocalyx disruption, vasopressin deficiency, adenosine triphosphate (ATP)-sensitive potassium channel activation, and adrenergic receptor desensitization-are discussed in relation to their clinical expression and therapeutic implications.Particular emphasis is placed on vasoplegic shock in Indian and tropical settings, where delayed presentation, tropical infections, anemia, malnutrition, and heightened endothelial vulnerability substantially influence shock biology and treatment response.The review highlights pragmatic bedside phenotyping approaches that rely on clinical course, vasopressor responsiveness, lactate dynamics, and focused echocardiography, enabling individualized therapy without dependence on advanced monitoring or omics.Evolving management strategies-including early vasopressor combination therapy, conservative fluid stewardship, and selective use of noncatecholamine agents such as vasopressin, methylene blue, and angiotensin II-are critically appraised.By reframing vasoplegic shock as a dynamic and biologically heterogeneous syndrome, this review underscores the need for early phenotypic recognition and context-adapted precision care to improve outcomes, particularly in resource-limited intensive care units.