Timing of hemoadsorption in sepsis: redefining early through mediator-guided therapy

BACKGROUND: Hemoadsorption is gaining acceptance as an adjunctive extracorporeal blood purification strategy in sepsis and septic shock; however, its clinical value remains contingent on two closely linked variables: when therapy is initiated and in whom it should be used. This review synthesizes the pathophysiological rationale, conceptual models of mediator removal, available devices, and clinical evidence for hemoadsorption in sepsis, with particular attention to patient selection. MAIN BODY: Sepsis is driven by a self-amplifying mediator cascade in which exogenous pathogenic substances and host response mediators increase rapidly, progressively committing potentially salvageable organs to injury and failure. Mechanistic theories of blood purification provide a rationale for early hemoadsorption, when mediator concentrations are high and dysregulated. Clinical evidence, however, remains limited: polymyxin B hemoadsorption guided by the endotoxin activity assay has demonstrated a survival benefit in a randomized trial, whereas supportive findings for cytokine adsorption derive largely from small trials, observational cohorts, and subgroup or post hoc analyses. These findings remain hypothesis-generating and require prospective validation in biomarker-enriched, phenotype-guided randomized trials. CONCLUSION: Current evidence supports moving beyond a fixed hours-from-onset definition of "early" treatment toward a biological definition, in which hemoadsorption is initiated in patients with a dysregulated hyperinflammatory host response, after key inflammatory mediators have crossed a toxic threshold and before irreversible organ injury becomes established.