Guidelines for the transfusion of red cells

Quality of Evidence-Based Guidelines for Transfusion of Red Blood Cells and Plasma: A Systematic Review

Many transfusion guidelines are available, but little appraisal of their quality has been undertaken. The quality of guidelines may potentially influence adoption. Our aim was to determine the quality of evidence-based transfusion guidelines (EBG) for red cells and plasma, using the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument, and assess duplication and consistency of recommendations. MEDLINE and EMBASE were systematically searched for EBG from 2005 to June 3, 2016. Citations were reviewed for inclusion in duplicate. A guideline was included if it had a specified clinical question, described a systematic search strategy, included critical appraisal of the literature and a description of how recommendations were developed. Four to six physicians used AGREE II to appraise each guideline. Median and scaled scores were calculated, with each item scored on a scale of one to seven, seven representing the highest score. Of 6174 citations, 30 guidelines met inclusion criteria. Twenty six guidelines had recommendations for red cells and 18 included recommendations for plasma use. The median score, the scaled score and the interquartile range of the scaled score were: scope and purpose: median score 5, scaled score 60%, IQR (49-74%); stakeholder involvement 4, 43%, (33-49%); rigor of development 4, 41%, (19-59%); clarity of presentation 5, 69%, (52-81%); applicability 1, 16%, (9-23%); editorial independence 3, 43%, (20-58%). Sixteen guidelines were evaluated to have a scaled domain score of 50% or less. Variations in recommendations were found for the use of hemoglobin triggers for red cell transfusion in patients with acute coronary syndromes and for plasma use for patients with bleeding. Our findings document, limited rigor in guideline development and duplication and inconsistencies in recommendations for the same topic. The process of developing guidelines for red cells and plasma transfusion can be enhanced to improve implementation.

Application of a clot-based assay to measure the procoagulant activity of stored allogeneic red blood cell concentrates

BACKGROUND

Thrombotic effects are possible complications of red blood cell transfusion. The generation and accumulation of procoagulant red blood cell extracellular vesicles during storage may play an important role in these thrombotic effects. The objective of this study was to assess the value of a simple phospholipid-dependent clot-based assay (STA^®-Procoag-PPL) to estimate the procoagulant activity of stored red blood cells and changes in this activity during storage of the blood component.

MATERIALS AND METHODS

Extracellular vesicles from 12 red blood cell concentrates were isolated at 13 storage time-points and characterised by quantitative and functional methods: the degree of haemolysis (direct spectrophotometry), the quantification and determination of cellular origin (flow cytometry) and the procoagulant activity (thrombin generation and STA^®-Procoag-PPL assays) were assessed.

RESULTS

The mean clotting time of extracellular vesicles isolated from red blood cell concentrates decreased from 117.2±3.6 sec on the day of collection to 33.8±1.3 sec at the end of the storage period. This illustrates the phospholipid-dependent procoagulant activity of these extracellular vesicles, as confirmed by thrombin generation. Results of the peak of thrombin and the STA^®-Procoag-PPL were well correlated (partial r=-0.41. p<0.001). In parallel, an exponential increase of the number of red blood cell-derived extracellular vesicles from 1,779/μL to 218,451/μL was observed.

DISCUSSION

The STA^®-Procoag-PPL is a potentially useful technique for assessing the procoagulant activity of a red blood cell concentrate.

A Systematic Review and Meta-Analysis of the Clinical Appropriateness of Blood Transfusion in China

The issue of the clinical appropriateness of blood transfusion has become a focus of transfusion medicine worldwide. In China, irrational uses of blood have often been reported in recent years. However, to date there lacks a systematic review of the rational uses of blood. This study aimed to determine the clinical appropriateness of blood transfusion in China. We searched PubMed, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database, WanFang Database, and Chinese BioMedical Literature Database, and the retrieval cut-off date was June 31, 2015. SPSS 17.0 and MetaAnalyst 3.13 were employed as the statistics tools in this review. A pooled rate of clinical inappropriateness of transfusion was analyzed by DerSimonian-Laird method. In this study, a total of 39 observational studies were included, which related to 75,132 cases of blood transfusion. According to the meta-analysis results, the overall incidence of clinical inappropriateness of transfusion in China was estimated to be 37.3% (95% confidence interval [CI] [32.1, 42.8]). The subgroup analyses revealed that the pooled rates of clinical inappropriateness of transfusion of plasma, red blood cells (RBCs), cryoprecipitate, and platelets were 56.3% (95% CI [45.8, 66.2]), 30.9% (95% CI [27.1, 35.0]), 25.2% (95% CI [13.2, 42.7]), and 14.1% (95% CI [8.8, 21.9]), respectively. However, the pooled incidence of inappropriateness of transfusion in operative departments was 47.5% (95% CI [36.8, 58.3]), which was significantly higher than that in nonoperative departments, 25.8% (95% CI [18.7, 34.4], P < 0.05). The overall rates of inappropriate use were 36.7% (95% CI [30.2, 43.6]) in major cities and 37.5% (95% CI [31.2, 44.3]) in other cities, respectively; there was no statistically significant difference (P > 0.05). In conclusion, China has suffered from a disadvantage in the clinical appropriateness of blood transfusion, especially in plasma and RBC use. In future, comprehensive measures should be implemented in order to improve the clinical appropriateness of blood transfusion.