Impact of Blood Donor Clinic Closures on the Age of Blood Transfused In a Tertiary Care Centre
Authors: Patriquin Christopher J. , Hsia Cyrus C. , Chin-Yee Ian H. 
Published: October 2019

Abstract
Abstract 4413

INTRODUCTION:
Red Blood Cells (RBCs) are stored for up to 42 days during which time multiple changes to the cells and media occur. This is collectively referred to as the “storage lesion.” Despite concern over the age of blood (AoB) transfused and the clinical impact of the storage lesion, there are no published data on the impact of donor clinic closures (DCCs) on the AoB transfused. In Canada, DCCs occur Sundays and statutory holidays and the Canadian Blood Services (CBS) can turn around products at the earliest within 24–48 hours. Thus regular DCCs could potentially affect the AoB transfused.

METHODS:
Data on all transfusions at London Health Sciences Centre (LHSC) between January 2006 and December 2008 were obtained. On average, LHSC issues approximately 25 000 RBC transfusions per year. Data included AoB and blood group for the transfused product, patient demographics, and admitting medical service. Dates for DCCs were obtained from CBS. Outcome measures included mean and variability of AoB transfused by day, month and year. Secondary outcome measures were the AoB transfused in relation to DCCs, and AoB transfused in various patient groups. Statistical analysis of categorical variables was analyzed with the Fisher's exact test and interval measures with the Student's t-test.

RESULTS:
A total of 67 449 transfusions were analyzed. The average AoB transfused was 20.5 days (d), with a range of 1 to 42 days. Greatest variation between days of the week was Tuesday and Saturday (20.7 vs 19.4d, p<0.001). Comparing Tuesday (2d post-DCC) and Sunday revealed significantly older blood issued on Tuesday (20.7 vs 19.5d, p<0.001). By month, the oldest blood was transfused in January (22.2d), the freshest in September (18.4d), with a difference of 3.8d (p<0.001). The year 2006 had the oldest AoB, 2007 the freshest (21.3 vs. 18.7d, D=2.6d, p<0.001). Analysis of the 5 days before and after holidays found that older blood was issued post-DCC for all holidays save New Year's Day. The oldest AoB by blood group was AB (31.3d), followed by B (25.8d), A (19.4d) and O (18.3d). Of the medical services, the newest transfusions were used by general surgery (19.2d), ICU (19.2d), and the ER (19.7d).

CONCLUSION:
The average AoB transfused was 20.5 days. Analysis of data by day of the week demonstrated similar AoB values. However, we did find AoB 2 days after regular DCCs was older than the days prior, as well as after all holiday DCCs except New Year's, likely due to two DCCs directly before it (Christmas Day and December 26). Analysis of AoB by blood group found the oldest blood to be AB, followed by B, A and O, corresponding with the national prevalence of ABO groups. One would expect a rarer group to have a smaller product pool from which to draw. Services using the freshest blood were surgery, ICU and ER, likely due to greater use of O units in resuscitation. Despite a trend of older RBCs being transfused in the period following DCCs the minor absolute differences observed are unlikely to represent a clinically significant impact for the recipient.

Disclosures:
No relevant conflicts of interest to declare.