Abstract
Background:
The American Association of Blood Banks (AABB) 2012 Guidelines recommend a restrictive transfusion strategy of 7 g/dL to 8 g/dL in asymptomatic, hemodynamically stable patients (pts) and for Hgb less than 8 g/dL in pts with preexisting cardiovascular disease. [1] Additional recommendations based on expert opinion include transfusion at threshold Hgb of 7 g/dL for hemodynamically stable ICU pts and Hgb less than 10 g/dL in pts with symptomatic anemia. We examined adherence to these guidelines and for differences in outcomes between restrictive and non-restrictive approaches at an academic hospital.
Methods:
We performed an IRB-approved retrospective review of all pts admitted to the Internal Medicine Service at University Hospital in Newark, New Jersey from July 1st to November 30th 2015 who received RBC transfusions. Charts were abstracted for demographic information, past medical history, indication for transfusion, presence of signs or symptoms of anemia (chest pain, orthostatic hypotension or tachycardia unresponsive to fluid resuscitation, or congestive heart failure), pre-transfusion Hgb, number of units transfused, and post-transfusion hgb. Outcomes were defined as requirement for additional transfusions, infections, cardiovascular events, adverse transfusion reactions, and death within 30 days of transfusion. Each transfusion was categorized as either adherent or non-adherent to the guidelines. Difference in outcomes between groups (adherent vs non-adherent) was tested using chi-square and Fisher's exact test with SAS studio version 3.4 (Cary, NC).
Results:
We reviewed 318 RBC transfusion records for 210 pts (median age: 55±17 years) with 157 (49%) transfusions in male and 161 (51%) in female pts. Site was ICU for 86 and the ward for 232 transfusions. The leading indication was acute bleeding (121 or 38%; pre-transfusion Hgb 6.9±1.3g/dL), followed by asymptomatic anemia (107 or 33%; pre-transfusion Hgb 6.8±0.8g/dL), and symptomatic anemia (91 or 29%; pre-transfusion Hgb 6.6±0.8g/dL). Of the 107 pts with asymptomatic anemia, 37 had pre-existing heart disease. Within this group, 35 were transfused at Hgb < 8g/dL (adherence of 95%). Seventy of the 107 transfusions were performed in pts without pre-existing cardiac disease. Fifty-nine were transfused at hgb < 7g/dL with an adherence of 84%. In the ICU, 21 of the 27 transfusions occurred for hgb < 7 g/dL in hemodynamically stable pts with an adherence of 78%. There were 91 transfusions for symptomatic anemia and all were adherent (100%). Regarding 30 day post-transfusion outcomes, there were 140 (44%) with subsequent transfusions; 54 (14%) infections; 7 (2.2%) cardiovascular events; 8 (2.5%) transfusion adverse reactions; 27(8%) deaths. No difference was detected for 30 day outcomes between the adherent group and the non-adherent group. (Table 1) Transfusion of at least 2unitsRBC in asymptomatic, symptomatic, and active bleeding pts were 25% (27/107), 44% (40/91), 57% (69/120) respectively. No difference in outcomes was found for the group receiving only 1 unit RBC (restrictive) compared to the group receiving 2 or more units RBC (non-restrictive). (Table 1)
Conclusion:
The majority of transfusions (92%) performed adhered to current guideline. While the restrictive approach was not associated with more complications or mortality, this study is limited by the small sample size and further work is being done.
Acknowledgment:
The authors are grateful to Dr. Koshy, Director of Blood Bank at University Hospital, for assistance.
Reference:
1. Carson, J. L. et al. Red blood cell transfusion: a clinical practice guideline from the AABB. Ann Intern Med 157, 49-58 (2012).
Disclosures
Chang: Johnson and Johnson: Other: Stock; Amgen: Other: Research; Boehringer Ingelheim: Other: Research.
Conditional Inference in Small Sample Scenarios Using a Resampling Approach