A retrospective observational analysis of red blood cell transfusion practices in stable, non-bleeding adult patients admitted to nine medical-surgical intensive care units

Background Red blood cell (RBC) transfusions are common procedures performed in the intensive care unit (ICU). However, conservative transfusion approaches have been recommended to avoid RBC transfusions that are not clinically necessary and to achieve optimal patient outcomes. The objective of this study was to examine the utilization and costs of RBC transfusions in medical-surgical ICUs and to compare this information against clinical guideline recommendations for best practice. Methods Retrospective observational analysis of RBC transfusions in stable, non-bleeding adult patients was examined in a geographically-defined, population-based cohort of nine integrated ICUs between April 1, 2014 and December 31, 2016. RBC transfusions associated with a pre-transfusion hemoglobin value of 70 g/L or more were examined through linear and logistic regression. The total costs of RBC transfusions, based on the RBC unit cost, were estimated. Results A total of 4632 RBC transfusions (2287 ICU admissions) were included. Pre-transfusion hemoglobin values were identified for 4487 transfusions. On average, 61% occurred at or above a hemoglobin value of 70 g/L (mean 73.4 ± 9.2 g/L). Factors associated with such transfusions included being male, age over 75, Sequential Organ Failure Assessment (SOFA) score greater or equal to 10, transfer from operating room, gastrointestinal bleeding, and trauma. A pre-transfusion hemoglobin value at or above 70 g/L was associated with increased odds of ICU mortality; there was no impact on overall hospital mortality. The total estimated cost of RBC transfusions was $2.99M Canadian dollars (CAD), with $1.82M CAD attributed to those with a hemoglobin value at or above 70 g/L. Conclusions Over half of the examined RBC transfusions may not have aligned with recommended best practice; this suggests significant opportunity for improvement. The present findings are an essential step towards optimizing RBC transfusions in the ICU.