Fragmented and locally siloed data limit progress in critical care research and education. The European Health Data Space (EHDS) proposes a federated, privacy-preserving framework to connect intensive care units (ICUs) across Europe. Sepsis is an ideal model condition given its heterogeneity, high mortality, and persistent gaps in standardization and outcomes.
This narrative review explores how federated and synthetic data can transform sepsis research, quality improvement, and education within the EHDS. It aims to outline both the opportunities and practical limitations of building a European-wide, learning ICU network.
Recent literature, European policy documents, and federated data initiatives were reviewed to synthesize conceptual, technical, and ethical aspects of implementing federated learning in intensive care.
Federated infrastructures enable joint analysis of distributed ICU data without sharing patient-level information, supporting benchmarking and surveillance while maintaining privacy. Synthetic data add value for simulation, algorithm testing, and training but cannot replace real-world complexity. Major barriers include data harmonization, interoperability, and governance. Ongoing projects demonstrate that transparent, secure frameworks can make responsible data sharing feasible.
The EHDS offers a realistic foundation for connecting ICUs across Europe through ethically governed federated systems. Combining clinical, engineering, and data science expertise will be key to transforming fragmented ICU information into shared intelligence that supports sepsis research, education, and personalized critical care.
There is a willingness to move towards a more personalised medicine; however, the red blood cells’ (RBC) transfusion decision-making process remains a one-size-fits-all practice in most non-bleeding critically ill patients. This narrative review describes the limitations of a transfusion decision-making process based only on haemoglobin (Hb) threshold and the potential physiological triggers of RBC transfusion with the clinical evidence investigating their implementation in routine.
Hb does not reflect tissue oxygenation and anaemia tolerance, and applying the same Hb threshold throughout the ICU stay neither prevents unnecessary transfusion nor insufficient transfusion. Central venous oxygen saturation (ScvO2) and oxygen extraction ratio (O2ER) are accessible at the bedside and display significant changes after RBC transfusion when in abnormal ranges. Although they have been prospectively investigated in the transfusion decision process, there is a need for more evidence to definitely implement them in routine. The arterial–venous difference in oxygen (A–VO2diff) might be another useful bedside RBC transfusion trigger. Microcirculatory markers are also promising candidates for physiological determinants for RBC transfusion.
There is a need for additional determinants in the RBC transfusion decision process to offset the limitations of RBC transfusion based only on Hb level in non-bleeding critically ill patients. A multimodal strategy, including comorbidities, underlying diseases, clinical signs, ECG changes, biochemical markers, and microcirculatory assessment, may optimise transfusion timing and avoid unnecessary red blood cell administration. However, further research is warranted to determine the potential benefit of integrating tissue oxygenation and microcirculatory parameters in the transfusion decision-making process.

