Red Blood Cell Distribution Width As Prognostic Factor in Sepsis: A New Use for a Classical Parameter

Purpose: To evaluate Red blood cell distribution width (RDW) as a sepsis prognostic biomarker.

Methods: 203 septic patients admitted to the ICU. Analysis of RDW dynamics, hospital mortality discrimination ability and the added value when incorporated to the SOFA, LODS, SAPS-II and APACHE-II scores using the AUC-ROC.

Results: Non-survivors presented higher RDW values during the first week after ICU admission (p = 0.048). Only SOFA and RDW were independently associated with mortality when adjusted by Charlson, immunosuppression, nosocomial infection, NEWS2, SAPS-II, septic shock and haemoglobin (p < 0.05). After adjustment, AUC-ROC was 0.827, 0.822, 0.824, 0.834 and 0.812 for each model including admission, 24, 48 and 72-h and 7-days RDW, respectively. When added to the scores, 24-h RDW and admission RDW improved their discrimination ability (SOFA AUC-ROC = 0.772 vs 0.812 SOFA + admission RDW, p = 0.041; LODS AUC-ROC = 0.687 vs 0.710, p = 0.002; SAPS-II AUC-ROC = 0.734 vs 0.785, p = 0.021; APACHE-II AUC-ROC = 0.672 vs 0.755, p = 0.003). Admission RDW with SOFA presented the better discrimination ability for mortality.

Conclusion: RDW is an independent prognostic marker of death in septic patients admitted in the ICU that improves SOFA, LODS, APACHE-II and SAPS-II discrimination ability. This parameter could be incorporated to the prognostic scores as a marker of systemic dysfunction and dysregulated inflammatory response.