Iron Deficiency at ICU Discharge

IRON-RECOVERY is a prospective, multicenter, observational cohort study designed to determine the prevalence of iron deficiency at intensive care unit (ICU) discharge and to evaluate its association with post-ICU clinical recovery. Anemia is highly prevalent in critically ill patients and frequently persists after ICU discharge. Although inflammation-induced iron dysregulation is considered one of the main mechanisms underlying persistent anemia, iron deficiency remains largely under-recognized in this population because conventional biomarkers, particularly ferritin, are influenced by the inflammatory response. Transferrin saturation (TSAT) has emerged as a more reliable marker of iron availability and may better identify patients with iron-restricted erythropoiesis. Adult patients admitted to participating ICUs for at least 72 hours will undergo assessment of iron status at ICU discharge using routine laboratory tests, including hemoglobin, serum iron, transferrin, ferritin, TSAT, and inflammatory markers. When available, admission iron parameters will also be collected to evaluate changes during the ICU stay. No study-specific therapeutic intervention will be mandated, and all treatment decisions, including intravenous iron administration, will remain at the discretion of the treating physicians. The primary objective is to determine the prevalence of iron deficiency (defined as TSAT \

Inclusion criteria: * Age ≥18 years * ICU length of stay ≥72 hours * Survival to ICU discharge Exclusion criteria: * Known hematologic diseases affecting erythropoiesis (e.g., aplastic anemia, myelodysplastic syndromes) * Pregnancy