Red blood cell transfusion practices amongst Canadian anesthesiologists: A survey

Purpose: To assess red blood cell transfusion practices among Canadian anesthesiologists. Methods: A survey depicting three realistic clinical scenarios of elective surgical procedures with different risks of bleeding was administered to all Canadian practicing members (n = 2,100) of the Canadian Anesthesiologists' Society. Respondents were requested to choose hemoglobin thresholds for which they would transfuse red blood cells under various conditions within each scenario. Results: We obtained a response rate of 47% (719/1,512). Transfusion thresholds differed significantly between baseline scenarios. A threshold above 70 g·L^-1 was chosen by 48% of respondents in the general surgery scenario compared to 56% in the orthopedic surgery scenario and 79% in the vascular surgery scenario (P < 0.001). A history of coronary artery disease was associated with a transfusion threshold ≥ 100 g·L^-1 in a significant proportion of respondents ranging from 20% in the orthopedic surgery scenario to 31% in the general surgery scenario and to 49% in the vascular surgery scenario (P < 0.001). Conversely, changing the patient's age from 60 to 20 yr resulted in the adoption of a transfusion threshold ≤ 60 g·L^-1 by > 30% of respondents in two scenarios (P < 0.001). The year of respondent graduation was strongly associated with these findings. Conclusion: There was significant variation in transfusion practices among Canadian anesthesiologists. The type of surgical procedure, patient's age and a history of coronary artery disease influenced reported transfusion threshold. Practice variation in specific subgroups would support the need for further research to identify optimal transfusion thresholds.