Prognostic role of albumin, lactate-to-albumin ratio and C-reactive protein-to-albumin ratio in infected patients

The prognostic evaluation of the septic patient has recently been enriched by some predictive indices such as albumin concentration, lactate/albumin ratio (LAR) and C-reactive protein/albumin ratio (CAR). The performance of these indices has been evaluated in septic patients in intensive care, but until now their performance in infected patients in the Emergency Department (ED) has not been evaluated. To investigate the potential prognostic role of albumin, LAR and CAR in patients with infection in the ED. Single-centre prospective study performed between 1 January 2021 and 31 December 2021 at the ED of the Merano Hospital (Italy). All patients with infection were enrolled. The study outcome was death within 30 days. The predictive ability of albumin, LAR and CAR was assessed by area under the receiver operating characteristic curves (AUROCs). A multivariate logistic regression model was used to examine the association of the indices with 30-day mortality, with comorbidity, acute urgency and severity of infection as covariates. The study enrolled 962 patients with an infectious status. The overall 30-day mortality rate was 8.9% (86/962). The AUROC of albumin was 0.831 (95% CI 0.795–868), while for LAR this was 0.773 (CI95% 0.719–0.827) and for CAR 0.718 (CI95% 0.664–0.771). The odds ratio for 30-day mortality for albumin was 3.362 (95% CI 1.904–5.936), for ln(LAR) 2.651 (95% CI 1.646–4.270) and for ln(CAR) 1.739 (95% CI 1.326–2.281). All three indices had a good discriminatory ability for the risk of short-term death in patients with infection, indicating their promising use in the ED as well as in the ICU. Further studies are needed to confirm the better performance of albumin compared to LAR and CAR.