Background: Clinical guidelines recommend a restrictive transfusion strategy in nonhemorrhaging critically ill patients.
Study design and methods: We conducted a retrospective observational study of 3533 single-admission patients, without evidence of acute coronary syndromes, hemorrhage, or hemoglobinopathy admitted to the medical intensive care unit (MICU) of a large, academic medical center.
Results: MICU admission hemoglobin (Hb) level did not change significantly over the study period. The proportion of transfused patients decreased from 31.0% in 1997 to 1998 to 18.0% in 2006 to 2007 (p<0.001). Among patients receiving transfusion, the mean pretransfusion Hb level decreased over time from 7.9±1.3 to 7.3±1.3g/dL (p<0.001). These changes in practice were not accounted for by differences in patient characteristics. The mean nadir Hb level in nontransfused patients decreased from 11.2±2.2g/dL in 1997 to 1999 to 10.4±2.3g/dL in 2006 to 2007 (p<0.001). The mean number of units per patient transfused decreased during this time from 4.3±4.7 to 3.0±3.8 units (p<0.001). The proportion of transfused patients who were transfused at a Hb level of less than 7.0g/dL increased by an estimated absolute increment of 3.2% (95% CI, 2.1%-4.3%) per interval (p<0.001), and the proportion of single-unit transfusions during the first transfusion episode increased by 1.4% per interval (95% CI, 0.2 to 2.6%; p=0.03) from 40.2% in 1997 to 1998 to 53.1% in 2006 to 2007.
Conclusions: Between 1997 and 2007, important and sustained changes have occurred in our MICU physician transfusion practices, with overall reductions in the proportion of patients transfused, mean pretransfusion Hb level, and nadir Hb level in patients who were not transfused.
© 2010 American Association of Blood Banks.