Survey of Red Blood Cell Transfusion Practices in Medically Ill Patients.

Although red cell transfusion is a relatively common treatment used in medically ill patients, much is not known about clinical determinants used to guide its use. A cross-sectional self-administered survey was used to assess the red blood cell transfusion practices of academic medical internists, subspecialty physicians and internal medicine residents who practice on the Medical Teaching Unit (MTU) at the Queen Elizabeth II Health Sciences Center, Halifax, Nova Scotia. We evaluated transfusion thresholds before transfusion and the number of red cell units ordered for four clinical scenarios: chronic obstructive pulmonary disease (COPD), coronary artery disease (CAD), gastrointestinal bleeding and delirium. Clinical characteristics were varied to further clarify clinical determinants of transfusion. The response rate among the forty-nine medical internists and subspecialty physicians was 59%. Among internal medicine residents the response rate was 100% (n=14). The primary area of practice for the majority of respondents was general internal medicine. Most staff physicians attended on the MTU for greater than four weeks. Baseline hemoglobin transfusion thresholds averaged from 75.6 +/− 9.8 g/L in a patient with acute delirium to 91.4 +/− 11.4 g/L in the gastrointestinal bleeding scenario. Range of baseline hemoglobin transfusion thresholds within scenarios was as wide as 60 to 120 g/L. Between the four scenarios, baseline hemoglobin transfusion thresholds differed significantly (p<0.03) except between the CAD and gastrointestinal bleeding scenarios. Clinical factors age and gender did not significantly (p>0.05) alter hemoglobin transfusion thresholds in the CAD and delirium scenarios, but were significant (p<0.02) modifiers of hemoglobin transfusion thresholds along with oxygen saturation, lactic acidosis, hemodynamic stability, requirement for urgent surgery, and chronic surgery in all other scenarios. Comparing staff physicians and internal medicine residents, there was no significant difference between the two groups for baseline hemoglobin transfusion thresholds. In conclusion, among physicians caring for medically ill patients, there is significant variation in red blood cell transfusion practices. Consistent with research in the critical care setting, pre-transfusion hemoglobin, along with other clinical factors, continues to be an important determinant of red cell transfusion.