Aim: The aim of this study is to quantify the red blood cell (RBC) transfusion threshold in critically ill patients
and to examine the relationship between RBC transfusion and clinical outcomes.
Materials and Methods: Five hundred and twenty patients who were admitted to the internal medicine
intensive care unit (ICU) between February 2018 and May 2019 were included in this study. The collected
data included patients’ demographic characteristics, admission diagnostic categories, co-morbidities, the ICU
admission Simplified Acute Physiology Scores (SAPS) II, numbers of RBC transfusion, ICU admission and
pretransfusion hemoglobin levels, and requirements of invasive mechanical ventilation and vasoactive drugs
during the ICU stay. The primary endpoint of the study was to determine the RBC transfusion threshold in
critically ill patients. Secondary outcomes were the ICU length of stay and mortality.
Results: A total of 89 (17.1%) patients received RBC transfusion during the ICU stay. The transfusion threshold
hemoglobin was 6.9 g/dL in transfused patients. Transfused patients had higher SAPS II scores at ICU admission
than non-transfused patients (p<0.001). The number of patients requiring invasive mechanical ventilation and
vasopressor support was higher in transfused patients (p<0.001). ICU mortality rates were higher in patients
who had received RBC transfusion during the ICU stay than in those who did not (ICU mortality rates were
51.7% and 23.9%, respectively).
Conclusion: This study showed that one-fifth of ICU patients received RBC transfusion during the ICU stay.
Transfused patients had higher disease scores and lower hemoglobin levels on the day of ICU admission.
Transfused patients stayed longer in the ICU and had higher mortality rates than non-transfused patients.