Estimated plasma volume status is a simple and quick tool that could help define the severity of patients with infection on arrival at the emergency department

Background: Infectious states are subtle and rapidly evolving conditions observed daily in the emergency department (ED), and their prognostic evaluation remains a complex clinical challenge. Recently, estimated plasma volume status (ePVS) has been suggested to have a prognostic role in conditions where volemic alteration is central to the pathophysiology. The aim of this study was to verify whether ePVS recorded at ED admission can provide prognostic indications of 30-day mortality in patients with infection. Methods: A prospective observational study was performed between 1 January 2021 and 31 December 2021 at the ED of the Merano Hospital. All patients with infection were enrolled. ePVS values were derived from haemoglobin and haematocrit measured on the immediate arrival of patients in the ED. The predictive power of ePVS for 30-day mortality was assessed using a multivariate model adjusted for severity, comorbidity and urgency. Kaplan-Meier analysis was also performed. Results: Of the 949 patients with infection enrolled in the study (47.9%, SOFA >= 2), 8.9% (84/949) died at 30 days. The median ePVS value was higher in patients who died at 30 days than in patients who survived (5.83 vs. 4.61, p < 0.001). Multivariate analysis revealed that ePVS in both continuous and categorical form around the median was an independent risk factor for 30-day mortality even after adjusting for severity, comorbidity and urgency. Kaplan-Meier analysis confirmed an increased risk of death in patients with high ePVS values. Conclusions: ePVS recorded on ED admission of patients with infection was an independent predictor of risk for 30-day mortality.