515 Compliance with a Restrictive Blood Transfusion Strategy: Do We Actually Follow Scientific Evidence?

Abstract Introduction Many burn centers use a restrictive blood transfusion strategy based on randomized controlled trials in burn patients (e.g. Transfusion Requirements in Burn Care Evaluation -TRIBE) and non-burn populations (e.g. Transfusion Requirements in Critical Care – TRICC), which have demonstrated no increased morbidity or mortality between restrictive and liberal transfusion approaches. The purpose of this study was to evaluate the adherence to a restrictive hemoglobin transfusion trigger strategy of 7 g/dL. Methods Retrospective study of all patients admitted to an adult regional ABA-verified burn centre between 15/11/ 2015 and 15/6/2018 who received at least one unit of blood (RBC). We use a restrictive transfusion strategy that administers RBC for a hemoglobin (HGb) < 7 gm/dL, one unit at a time, with a pre and post HGb level for each RBC transfusion, unless the patient is actively bleeding and/or hemodynamically unstable. RBC transfusions in the operating room do not follow this policy and were not studied. Values are presented as mean ± SD or median (IQR) as appropriate. Results We studied 66 patients (30% female) with age 53.2 ± 18.3 years, % TBSA burn 22 (11–41), % TBSA full thickness burn 6.5 (0.5 -21.8), and with 41% having inhalation injury. Overall, there were 691 RBC transfusions (TXns). A pre-TXn HGb was obtained 95% of the time and was 6.8 (6.5–7) gm/dL. TXn for a HGb > 7 gm/dL occurred in 35%. A post TXn HGb was obtained for 92% of these TXns with a HGb of 7.6 (7.2–8) gm/dL. RBC TXns during nighttime (1700 to 0800, n=449) were given for a HGb trigger of 6.8 (6.4–6.9) and were not compliant with our restrictive strategy 22% of the time. Daytime transfusions (0800 to 1700, n=207) were given for a significantly higher HGb [7 (6.7–7.1), p< 0.001] with significantly more non-compliance with the restrictive strategy (50%, p< 0.001). We also compared TXns before and after the TRIBE publication. Pre-TRIBE TXns (n=484) were given for significantly lower HGb than 172 post TRIBE TXns [6.8 (6.4–7) vs 6.9 (6.6–7.1) gm/dL respectively, p=0.001] and at significantly lower rate of non-compliance with the 7 gm/dL threshold than post TRIBE transfusions (28.1% vs 37.8%, respectively, p=0.02). Conclusions While a pre-TXn HGb level was available for 95% of blood transfusions, approximately one-third were given for a HGb > 7 gm/dL. Transfusion during nighttime (being predominantly ordered by housestaff physicians) were administered at a significantly lower HGb trigger and with significantly better compliance with the restrictive strategy than daytime transfusions. Paradoxically, compliance with the restrictive strategy was worse following the TRIBE publication. Applicability of Research to Practice These results identify important areas for improvement in adherence to our restrictive transfusion strategy.