A positive blood culture is associated with a lower haemoglobin increment in hospitalized patients after red blood cell transfusion.

BACKGROUND AND OBJECTIVES: Abundant clinical evidence supports the safety of red blood cell (RBC) concentrates for transfusion irrespective of storage age, but still, less is known about how recipient characteristics may affect post-transfusion RBC recovery and function. Septic patients are frequently transfused. We hypothesized that the recipient environment in patients with septicaemia would blunt the increase in post-transfusion blood haemoglobin (Hb). The main objective was to compare the post-transfusion Hb increment in hospitalized patients with or without a positive blood culture. MATERIALS AND METHODS: A retrospective cohort study using data from the Transfusion Research, Utilization, Surveillance, and Tracking database (TRUST) was performed. All adult non-trauma in-patients transfused between 2010 and 2017 with ≥1 RBC unit, and for whom both pre- and post-transfusion complete blood count and pre-transfusion blood culture data were available were included. A general linear model with binary blood culture positivity was fit for continuous Hb increment after transfusion and was adjusted for patient demographic parameters and transfusion-related covariates. RESULTS: Among 210,263 admitted patients, 6252 were transfused: 596 had positive cultures, and 5656 had negative blood cultures. A modelled Hb deficit of 1.50 g/L in blood culture-positive patients was found. All covariates had a significant effect on Hb increment, except for the age of the transfused RBC. CONCLUSION: Recipient blood culture positivity was associated with a statistically significant but modestly lower post-transfusion Hb increment in hospitalized patients. In isolation, the effect is unlikely to be clinically significant, but it could become so in combination with other recipient characteristics.

Utilising red cell antigen genotyping and serological phenotyping in sickle cell disease patients to risk-stratify patients for alloimmunisation risk.

BACKGROUND: Alloimmunisation and haemolytic transfusion reactions (HTRs) can occur in patients with sickle cell disease (SCD) despite providing phenotype-matched red blood cell (RBC) transfusions. Variant RBC antigen gene alleles/polymorphisms can lead to discrepancies in serological phenotyping. We evaluated differences between RBC antigen genotyping and phenotyping methods and retrospectively assessed if partial antigen expression may lead to increased risk of alloimmunisation and HTRs in SCD patients at a tertiary centre in Canada. METHODS: RBC antigen phenotyping and genotyping were performed by a reference laboratory on consenting SCD patients. Patient demographic, clinical and transfusion-related data were obtained from a local transfusion registry and chart review after research ethics board approval. RESULTS: A total of 106 SCD patients were enrolled, and 91% (n = 96) showed additional clinically relevant genotyping information when compared to serological phenotyping alone. FY*02N.01 (FY*B GATA-1) (n = 95; 90%) and RH variant alleles (n = 52, 49%; majority accompanied by FY*02N.01) were common, the latter with putative partial antigen expression in 25 patients. Variability in genotype-phenotype antigen prediction occurred mostly in the Rh system, notably with the e antigen (kappa: 0.17). Fifteen (14.2%) patients had a history of alloimmunisation, with five having HTR documented; no differences in clinical outcomes were found in patients with partial antigen expression. Genotype/extended-phenotype matching strategies may have prevented alloimmunisation events. CONCLUSION: We show a high frequency of variant alleles/polymorphisms in the SCD population, where genotyping may complement serological phenotyping. Genotyping SCD patients before transfusion may prevent alloimmunisation and HTRs, and knowledge of the FY*02N.01 variant allele increases feasibility of finding compatible blood.

Not all red cell concentrate units are equivalent: international survey of processing and in vitro quality data.

INTRODUCTION: In vitro qualitative differences exist in red cell concentrates (RCCs) units processed from whole blood (WB) depending on the method of processing. Minimal literature exists on differences in processing and variability in quality data. Therefore, we collected information from blood manufacturers worldwide regarding (1) details of WB collection and processing used to produce RCCs and (2) quality parameters and testing as part of routine quality programmes. METHODS: A secure web-based survey was developed, refined after pilot data collection and distributed to blood centres. Descriptive analyses were performed. RESULTS: Data from ten blood centres in nine countries were collected. Six blood centres (60%) processed RCCs using the top-and-top (TAT) method which produces RCCs and plasma, and eight centres (80%) used the bottom-and-top (BAT) which additionally produces buffy coat platelets. Five of the centres used both processing methods; however, four favoured BAT processing. One centre utilized the Reveos automated system exclusively. All centres performed pre-storage leucoreduction. Other parameters demonstrated variability, including active cooling at collection, length of hold before processing, donor haemoglobin limits, acceptable collection weights, collection sets, time to leucoreduction, centrifugation speeds, extraction devices and maximum RCC shelf life. Quality marker testing also differed amongst blood centres. Trends towards higher RCC unit volume, haemolysis and residual leucoctyes were seen in the TAT compared with BAT processing across centres. CONCLUSION: Methods and parameters of WB processing and quality testing of RCCs differ amongst surveyed blood manufacturers. Further studies are needed to assess variations and to potentially improve methods and product quality.

Red blood cell processing methods and in-hospital mortality: a transfusion registry cohort study.

BACKGROUND: Quality of red blood cells (RBCs) varies depending on the method of processing the whole blood donation, and the method of processing might affect outcomes in patients transfused RBCs. We aimed to establish whether an association exists between in-hospital mortality and RBC processing method and duration of storage. METHODS: We did a retrospective registry cohort study using data from three acute care hospitals in Hamilton, ON, Canada, and Canadian Blood Services over a 6-year period (2008-14). Adult patients (≥18 years) who were admitted to hospital and who received RBC transfusions were included in the study. All transfused RBCs were characterised by the method of processing (red cell filtered or whole blood filtered) and storage age (fresh 1-7 days, mid 8-35 days, and old 36-42 days). The primary outcome was in-hospital mortality. We used Cox proportional hazards regression with time-dependent stratification variables and fixed stratification variables, and controlled for patient covariates. FINDINGS: Between April 1, 2008, and March 31, 2014, 91 065 RBC transfusions were given to 23 634 adults who were included in the analyses. When storage duration was included in the model, in-hospital mortality was significantly increased with fresh whole blood filtered units compared with the reference group of mid-age red cell filtered units (hazard ratio 2·19, 95% CI 1·09-4·42; p=0·033). Differences between other age and processing categories were not significant. INTERPRETATION: The potential effect of whole blood processing methods on patient outcomes is worthy of further investigation, since adverse outcomes could be reduced by minor changes to blood processing methods and inventory management policies. FUNDING: Canadian Blood Services, Health Canada, and the Canadian Institutes of Health Research.

A benchmarking program to reduce red blood cell outdating: implementation, evaluation, and a conceptual framework.

BACKGROUND: Benchmarking is a quality improvement tool that compares an organization's performance to that of its peers for selected indicators, to improve practice. STUDY DESIGN AND METHODS: Processes to develop evidence-based benchmarks for red blood cell (RBC) outdating in Ontario hospitals, based on RBC hospital disposition data from Canadian Blood Services, have been previously reported. These benchmarks were implemented in 160 hospitals provincewide with a multifaceted approach, which included hospital education, inventory management tools and resources, summaries of best practice recommendations, recognition of high-performing sites, and audit tools on the Transfusion Ontario website (http://transfusionontario.org). In this study we describe the implementation process and the impact of the benchmarking program on RBC outdating. A conceptual framework for continuous quality improvement of a benchmarking program was also developed. RESULTS: The RBC outdating rate for all hospitals trended downward continuously from April 2006 to February 2012, irrespective of hospitals' transfusion rates or their distance from the blood supplier. The highest annual outdating rate was 2.82%, at the beginning of the observation period. Each year brought further reductions, with a nadir outdating rate of 1.02% achieved in 2011. The key elements of the successful benchmarking strategy included dynamic targets, a comprehensive and evidence-based implementation strategy, ongoing information sharing, and a robust data system to track information. CONCLUSION: The Ontario benchmarking program for RBC outdating resulted in continuous and sustained quality improvement. Our conceptual iterative framework for benchmarking provides a guide for institutions implementing a benchmarking program.

An epidemiologic cohort study reviewing the practice of blood product transfusions among a population of pediatric oncology patients.

BACKGROUND: Despite the high utilization of blood products by pediatric oncology patients, literature in this population remains scarce. The primary objective of this study was to assess red blood cell (RBC) and platelet (PLT) utilization rates and transfusion thresholds in pediatric oncology patients. The secondary objective was to describe transfusion-related complications including RBC alloantibody development and transfusion reactions. STUDY DESIGN AND METHODS: This epidemiologic cohort study involved pediatric oncology patients at a Canadian academic children's hospital between April 2002 and December 2011. Demographic, clinical, laboratory, and transfusion variables were collected from the Transfusion Registry for Utilization Statistics and Tracking database, a large database that captures more than 50 demographic and clinical variables as well as comprehensive transfusion information and laboratory test results. RESULTS: Of 647 pediatric oncology patients, 430 (66%) received a RBC or PLT transfusion or both during this time period. The median transfusion threshold before a RBC and PLT transfusion was a hemoglobin (Hb) value of 72 g/L (interquartile range [IQR], 68-76 g/L) and a PLT count of 16 × 10(9) /L (IQR, 10 × 10(9) -23 × 10(9) /L), respectively. Ninety-two percent of the issued RBC and PLT products (7507/8154) were cytomegalovirus negative and 90% were irradiated (7299/8154). RBC alloantibody development and transfusion reactions were reported infrequently in 0.5% (2/423) and 4.5% (8/179) of the patients, respectively. CONCLUSION: This study assessed utilization rates, transfusion thresholds, alloantibody development, and transfusion reactions in pediatric oncology patients. The descriptive results from this epidemiologic study provide baseline information to generate hypotheses to be tested in future interventional studies.

The effect of blood storage duration on in-hospital mortality: a randomized controlled pilot feasibility trial.

BACKGROUND: Whether the duration of storage of blood has an impact on patient outcomes remains controversial. The objective was to determine feasibility of a comparative effectiveness trial to evaluate duration of storage of blood before transfusion on in-hospital mortality. STUDY DESIGN AND METHODS: A single-center randomized controlled trial was performed at an acute care hospital in Canada between June and December 2010, involving consecutive hospitalized patients needing blood transfusion. Patients (n=910) were randomly assigned in a 1:2 ratio to receive freshest available versus standard-issue (oldest available) blood. Four feasibility criteria were measured: proportion of eligible patients randomized, contrast in age of blood between treatment groups, real-time data acquisition, and trial impact on blood outdating. In-hospital mortality was also reported. RESULTS: A total of 1075 of 1129 patients (95.2%) were eligible and 910 of 1075 (84.7%) were randomized: 309 received freshest available blood (1157 units), and 601 received standard-age blood (2369 units). Contrast in mean age of the oldest blood transfused between groups was 14.6 days: 12.0 (standard deviation [SD], 6.8) days in the fresh arm and 26.6 (SD, 7.8) days in the standard arm. Weekly recruitment and event reporting were achieved for all patients. The blood outdate rate was 0.10%. In-hospital mortality was 10.5%: 35 deaths (11.3%) in the fresh arm and 61 deaths (10.1%) in the standard arm (odds ratio, 1.13; 95% confidence interval [CI], 0.73, 1.76). CONCLUSION: It is feasible to conduct a large comparative effectiveness trial comparing the effect of freshest available versus standard-issue blood on in-hospital mortality. The wide CI around the estimate for in-hospital mortality supports the need for a large trial.

A randomized controlled trial comparing standard- and low-dose strategies for transfusion of platelets (SToP) to patients with thrombocytopenia.

A noninferiority study was performed comparing low-dose and standard-dose prophylactic platelet transfusions. A double-blind randomized controlled trial (RCT) was performed in 6 sites in 3 countries. Thrombocytopenic adults requiring prophylactic platelet transfusion were randomly allocated to standard-dose (300-600 x 10(9) platelets/product) or low-dose (150- < 300 x 10(9) platelets/product) platelets. The primary outcome (World Health Organization [WHO] bleeding > or = grade 2) was assessed daily through clinical examination, patient interview, and chart review. A WHO grade was assigned through adjudication. The Data Safety Monitoring Board stopped the study because the difference in the grade 4 bleeding reached the prespecified threshold of 5%. At this time, 129 patients had been randomized and 119 patients were included in the analysis (58 low dose; 61 standard dose). Three patients in the low-dose arm (5.2%) had grade 4 bleeds compared with none in the standard-dose arm. WHO bleeding grade 2 or higher was 49.2% (30/61) in the standard-dose arm and 51.7% (30/58) in the low-dose group (relative risk [RR], 1.052; 95% confidence interval [CI], 0.737-1.502). A higher rate of grade 4 bleeding in patients receiving low-dose prophylactic platelet transfusions resulted in this RCT being stopped. Whether this finding was due to chance or represents a real difference requires further investigation. These clinical studies are registered on (http://www.clinicaltrials.gov) as NCT00420914.