Jummy Oladipo, MSc Candidate (Translational Medicine)
At the February 11th Medical Grand Rounds, the Department of Medicine had the honour of hosting Dr. Jeannie Callum, a professor and director of Transfusion Medicine at Queen’s University. Dr. Callum’s presentation gave an overview of transfusion guidelines, focusing on the need to improve the appropriateness and efficiency of transfusion practices.
Dr. Callum’s presentation began with an overview of Ontario’s blood utilization rates. Provincially, the red blood cell (RBC) and frozen plasma transfusion rates have decreased over time. While this is a step in the right direction, Dr. Callum noted that there is still room for improvement as recent province-wide audits displayed a high rate of inappropriate transfusions (1).
An overview of the updated guidelines for transfusion practices of RBC, platelets, plasma, and cryoprecipitate was presented. When discussing RBC transfusion, Dr. Callum provided evidence supporting the use of a restrictive transfusion approach over a liberal strategy. Many randomized control trials such as the Transfusion Requirements in Critical Care (TRICC) trial, and the Threshold in Transfusion in Septic Shock (TRISS) trial have compared the two strategies; almost all concluding that the restrictive method is the most efficient approach (2, 3). Dr. Callum outlined the RBC transfusion guidelines for the Kingston Health Sciences Centre which recommends a threshold of 70 g/L, one unit at a time, for the majority of inpatients (4). Emphasis was put on the importance of staying within the guidelines as resources lost on wasted blood could be put to better use in medicine.
Dr. Callum then went over the platelet transfusion guidelines and advised that physicians should avoid transfusing their patients above a platelet count of 10x109/L and should transfuse one unit at a time (4). This was based on studies showing no significant benefits from transfusions above this threshold. It was revealed that international normalized ratios are not required for low-risk procedures which many physicians are unaware of. There is large variation in plasma utilization rates across Ontario which Dr. Callum speculated could be attributed to institutional factors impacting physician ordering practices (1). Dr. Callum advised against ordering 1-2 doses of plasma as these are deemed placebo doses (1). In 2021, transfusion services are becoming more restrictive as to who requires plasma. There are many alternatives to plasma treatment which should be considered beforehand. Dr. Callum also indicated that cryoprecipitate is no longer transfused as fibrinogen concentrate has replaced it.
The Grand Rounds presentation concluded with Dr. Callum predicting where transfusion medicine is heading in 2021. Future endeavours include updating Ontario-wide protocols, new clinical trials, and implementing strategies to make blood cleaner.
In the post-rounds discussion, Dr. Callum and the TMED students focused on ways in which improving transfusion practices benefits patients. Transfusion medicine is shifting towards a more holistic approach, optimizing patient conditions before transfusion to minimize the amount of blood required. Some of the ongoing investigations in transfusion medicine were explained. Enzymes able to convert type A and B blood to type O (the universal donor) are underway and if successful, their use could increase blood’s storage capacity leading to less wastage (5).
The discussion progressed towards examining how transfusion guidelines are portrayed in the media. Topics related to increasing the diversity of blood donors were explored. Additionally, Dr. Callum highlighted many of the barriers that potential blood donors face preventing them from donating. Initiatives have been put in place to increase the awareness of the need for blood donations and increase access to donor sites. The effect of the pandemic on transfusion practices was also revealed. The pandemic brings many logistical challenges to transfusion services but also provides a unique opportunity for science to be more visible.
To conclude, the TMED students learned about Dr. Callum’s educational background. Dr. Callum completed her medical education at the University of Toronto and then pursued a fellowship in transfusion medicine with the Canadian Blood Services. The opportunities that transfusion medicine creates to collaborate with a wide variety of colleagues and patients is what drew her to the field. Dr. Callum advised those beginning their research careers to continually seek new opportunities, increase their professional networks and seek out mentorship as these are tools for a successful career. Having recently moved back to Kingston, Dr. Callum expressed how grateful she is for the opportunity to assist the KHSC in improving their Transfusion Medicine program.
It was a pleasure to hear Dr. Callum speak on transfusion medicine guidelines. On behalf of the TMED Graduate Program, we sincerely thank Dr. Callum for her time and extensive insight.
References:
1. Qiang JK, Thompson T, Callum J, Pinkerton P, Lin Y. Variations in RBC and frozen plasma utilization rates across 62 Ontario community hospitals. Transfusion. 2019;59(2):545-54.
2. Hebert PC, Wells G, Blajchman MA, Marshall J, Martin C, Pagliarello G, et al. A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. Transfusion Requirements in Critical Care Investigators, Canadian Critical Care Trials Group. N Engl J Med. 1999;340(6):409-17.
3. Holst LB, Haase N, Wetterslev J, Wernerman J, Guttormsen AB, Karlsson S, et al. Lower versus higher hemoglobin threshold for transfusion in septic shock. N Engl J Med. 2014;371(15):1381-91.
4. Callum JL, Pinkerton PH, Lima A, Lin Y, Karkouti K, Lieberman L, et al. Blood Easy 4: Blood Transfusions, Blood Alternatives and Transfusion Reactions: A Guide to Transfusion Medicine. Canada: Ontario Regional Blood Coordinating Network; 2016.
5. Rahfeld P, Withers SG. Toward universal donor blood: Enzymatic conversion of A and B to O type. J Biol Chem. 2020;295(2):325-34.