Evaluation of red cell transfusion practice in medical patients of a regional hospital in Hong Kong : a prospective study of transfusion practice and survey of clinicians

Abstract

Introduction: Blood products are precious resources and blood transfusion carries risks. Patient blood management is currently advocated to enhance clinical outcomes. Evolving evidence and guidelines suggest restrictive blood transfusion. Significant variations in transfusion practice among clinical services were observed, which could be due to non-adherence to guidelines and imprecise evidence on the optimal transfusion strategy. The transfusion practice in medical patients of a regional hospital and how it affected clinical and patient-reported outcomes were studied.

Method: A single centre prospective study in the medical department of a regional hospital was performed to evaluate the transfusion practice, including the transfusion trigger and number of red blood cell (RBC) units per transfusion. Clinical parameters were assessed before and after blood transfusion. Health-related quality of life (HRQOL) instruments were administered on transfusion day (Day 0), one (Day 1) and seven days (Day 7) after transfusion respectively. Single-unit and double-unit transfusion were compared by subsequent need of transfusion during Day 1 to Day 7, overall blood use in one week and the change in HRQOL. Factors potentially influenced transfusion decision and clinical outcomes were explored. Then, regression analysis was performed to study the relationship between different factors and the change in HRQOL. In order to understand the belief in blood transfusion, a survey of physicians was simultaneously conducted. Physicians were asked to indicate the transfusion trigger and number of RBC units in the three hypothetical scenarios. Conditions that may alter the transfusion trigger were also identified.

Results: 101 medical patients were recruited for analysis. The median transfusion trigger was 7.2 [6.5-7.8] g/dL. Two or more units of RBC were transfused in 47% of episodes. Comparing with guidelines, 40% of the transfusion episodes in hospitalised patients were deviated from the recommendations. Overall blood use in one week was 0.7 units less with single-unit transfusion (p < 0.001). The change in HRQOL did not show significant difference between single- or double-unit groups. Lower transfusion trigger was the only significant predictor of double-unit transfusion. Regression analysis showed that day care was associated with greater improvement in HRQOL on Day 1 but the effect disappeared on Day 7. The improvement in HRQOL was greater in those had worse scores on Day 0. Transfusion trigger, Charlson’s comorbidity index and number of RBC units transfused in past 7 days were not associated with the change in HRQOL.

In the survey of physicians, 60 completed questionnaires were received. More clinicians preferred a higher transfusion trigger and double-unit transfusion in the acute upper gastrointestinal bleeding and pneumonia scenarios than in the terminal cancer patient with pre-existing anaemia. Physicians transfused more liberally in elderly patients, and when there was concomitant ischaemic heart disease or acute coronary syndrome. Years of practice and training stage of doctors did not affect transfusion decision. Only 28% of clinicians reported awareness to evidence or guidelines related to RBC transfusion.

Conclusion: Transfusion trigger and units were variable in the centre. Significant proportion of transfusion was deviated from recommended practice. Double-unit transfusion increased overall blood use but it was not associated with better improvement in anaemic symptoms. Only few doctors reported awareness of evidence related to red cell transfusion. Clinicians tended to transfuse more liberally than recommendation of practicing guidelines in acute anaemic conditions, elderly or the presence of ischaemic heart disease. It is proposed that introduction of patient blood management and adherence to restrictive blood transfusion could enhance the transfusion practice in the centre.