Blood transfusion is a common requirement in the intensive care setting. Improved tissue oxygenation is the therapeutic objective of transfusion for normovolaemic anaemia. However, the efficiency with which red blood cells (RBCs) carry oxygen to the tissues has been questioned, particularly after prolonged storage. We measured the impact on oxygen transport variables (base excess, lactate and ScvO 2 ) of transfusion of a unit of stored RBCs in 45 critically ill adults. There were no significant changes in these variables, except for ScvO 2 , which increased with older units (≥ 20 days storage), suggesting impaired oxygen uptake by the tissues. The role of the storage lesion (structural and functional changes in the RBC acquired in storage media) is discussed with reference to its impact on oxygen delivery.
Computer based learning (CBL) is increasingly used to
Various low ionic strength diluents are used routinely for red cell alloantibody detection in the antiglobulin test to increase the rate of antibody association to antigen, thereby allowing a reduction in the incubation time while achieving optimal agglutination. Two commercial low ionic strength diluents (DiaMed ID-CellStab and Inverclyde LISS) were assessed using the DiaMed-ID LISS Coombs' microtube column system, to assess whether or not the choice of diluent influences red cell antibody detection. Effects of two low ionic strength diluents after 15-min incubation were assessed in 150 samples containing a wide range of typical red cell alloantibodies. Inverclyde LISS gave significantly higher reaction strengths in 25% of samples when compared with the same red cells suspended in ID-CellStab. Variation in reaction strengths ranged from 1+ to 2+, using Inverclyde LISS versus CellStab. Of 131 red cell alloantibodies directed against Rh, Kell, Kidd and Duffy antigens, Inverclyde LISS detected 90% after 15-min incubation, whereas 83% were detected with CellStab. This study suggests that Inverclyde LISS provides better red cell alloantibody detection than does ID-CellStab, and this may be due to the higher ionic strength of ID-CellStab.
4406 Methods of quantification of foetal red cell in maternal blood samples are important to ensure the correct administration of prophylactic anti-D to prevent sensitisation of the mother which may result in haemolytic disease of the newborn and foetus in subsequent pregnancies. We aimed to assess the accuracy of 3 methods: a gel card technique using anti-D and 2 acid-elution techniques, foetal cell detection kit (FCD, Inverclyde Biologicals Lanarkshire, Scotland) and a kit from Clin-Tech Limited (Guildford, England) based on the Kleihauer-Betke foetal stain technique (KBT), to quantifiy foetal red cells in maternal samples. The sensitivity of the gel method was also assessed. A total of 63 maternal blood samples and 30 man-made control blood samples were analysed, with only 57 maternal samples confirmed to be Rh D negative. Rh D positive samples were excluded. All samples were run concurrently with the 3 methods, according to manufacturers’ instructions. Mann Whitney test was used to compare the results. The gel technique was recorded in terms of grading of agglutination while the acid-elution kits were recorded by degree of FMH (mL). Column agglutination was also used to assess sensitivity. Results showed only 3 maternal samples were positive for FMH using the acid-elution method but not the gel technique. Statistically there was no significant difference between the techniques (Mann-Whitney test). Sensitivity of the gel method showed that it has the ability to detected FMH of more than 3mL whilst the 2 kits were able to detect FMH of 1mL. The study showed that gel technique required little skill to perform but it was not considered suitable for accurate quantification of FMH and consequently for the correct administration of prophylactic anti-D. The foetal cell detection kit (Inverclyde Biologicals) showed a similar ability to detect and quantify FMH when compared to the Kleihauer –Betke kit (Clin-Tech) with better overall staining intensity. The Kleihauer-Betke test from Clin-Tech and the foetal cell detection kit from Inverclyde Biologicals showed no significant difference (p = 0.98), thus there is no statistical significant difference between the 2 methods. However, the sensitivity of the column agglutination method was lower, as significant agglutination could only be observed with FMH of more than 3mL. The expected values were plotted based on Gomez-Arbones et al (2002), who cited significant agglutination seen when FMH is 0.1% or about 2.5mL. Sensitivity was found to be less than expected as a higher amount of bleed is required to observed significant agglutination. The FMH sample representing 1–6mL was repeated and similar findings were recorded, as significant agglutination was only observed when FMH was 4mL. The column agglutination method is not suitable as a quantitative measurement of FMH as it only allows qualitative analysis, thus if it is incorporated into a clinical setting, it must be accompanied by a quantitative test. The foetal cell detection kit has similar staining capabilities to detect foetal cells and compared to Clin-Tech was easier to use as there is no need to prepare eluting solution unlike the latter. However, fixing solution was not provided and hence need to be prepared. Results showed that only 3 maternal samples were positive for the presence of FMH and thus using a semi-quatitative acid-elution technique should be sufficient in FMH quantification unless FMH using the acid-elution technique exceeds 2mL, as recommende,d by the BCSH guidelines (2009), then the sample should be analysed using flow cytometry. Acknowledgments: Central Manchester Hospitals Transfusion Laboratory for the provision of blood samples. Performed as part of MSc Biomedical Science project, funded by Mancheste Metropolitan University. Disclosures: No relevant conflicts of interest to declare.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.