Phenotype-guided polymyxin B haemoadsorption in abdominal septic shock: a 2015-2026 evidence synthesis and proposed...

Polymyxin B haemoadsorption (HP-PMX) has generated a decade of contradictory evidence in septic shock. After the Tigris phase 3 Bayesian trial and the accumulation of Japanese and European cohorts, we synthesise the 2015-2026 literature and propose a clinical pathway for phenotype-guided indication at the bedside in European intensive care units (ICUs).

SANRA-aligned narrative review of PubMed/MEDLINE, Embase and Cochrane Library (January 2015-May 2026), with no language restriction and independent selection by two authors. The clinical pathway was derived from convergent domains identified in the literature without formal external consensus.

Available evidence converges on three domains defining a responder phenotype: detectable endotoxaemia (Endotoxin Activity Assay [EAA] 0.60-0.89); intermediate organ dysfunction (Sequential Organ Failure Assessment [SOFA] 7-13); intra-abdominal source, with early initiation as a fourth, operationally derived criterion. Tigris reported a marginal reduction in 90-day mortality of 15.5% (95% credible interval 3.6-27.1), with a posterior probability of benefit of 99.4% at 90 days and 95.3% at 28 days. Japanese (SOFA 7-12; n=4,066) and European (SOFA 8-13) cohorts describe an operatively equivalent severity range. Tanaka reported that the survival benefit concentrates in intra-abdominal infection (adjusted HR 0.485, 95% CI 0.252-0.935; p=0.031). A five-step decision algorithm is proposed in which SOFA 7-13 acts as a clinical surrogate when the EAA is unavailable.

HP-PMX is not a universal therapy for septic shock but an example of phenotype-guided therapy. The proposed pathway is a synthesis-derived framework intended to standardise bedside decision-making in European ICUs ahead of formal external validation, which we identify as the necessary next step.