Vox sanguinis
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In the USA, seasonal tickborne transmission of Babesia microti occurs in the Northeast and upper Midwest. A resident of Texas became infected through a red blood cell transfusion from an asymptomatic local donor who had summered in Massachusetts. ⋯ Premortem patient specimens and archived blood from the donor unit tested positive for B. microti antibodies and DNA. Babesiosis should be included in the differential diagnosis of post-transfusion haemolytic anaemia or thrombocytopenia, regardless of the geographical region or season.
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Antibody-mediated transfusion-related acute lung injury (TRALI) is an important cause of transfusion-associated morbidity and death. Preventive strategies are currently a matter of debate. ⋯ Compared to HLA class I antibodies, those directed against HLA class II and HNA-3a were of greater clinical relevance. Isolated HLA class I antibody screening was found to be insufficient for leucocyte antibody screening.
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Review Comparative Study
Rationale for randomized controlled trials and for intention-to-treat analysis in transfusion medicine: are they one and the same?
Articles on the appropriateness of intention-to-treat (ITT) vs. as-treated (AT) analyses of randomized controlled trials (RCTs) have highlighted issues relevant to drug trials, such as approaches suitable for 'explanatory' vs. 'pragmatic' RCTs. These considerations are less relevant to transfusion medicine RCTs, especially those of red blood cell transfusion therapies where the main issue is whether to include in the analysis randomized patients who did not receive transfusion. This article discusses issues pertinent specifically to transfusion medicine RCTs, and the thesis presented here is that the primary analysis of any transfusion medicine RCT must be based on the ITT principle. ⋯ Deviations from the ITT principle may be valid only when other conditions are met to ensure that non-adherence to ITT will not bias the results. For RCTs of red blood cell transfusion therapies, such conditions include that the RCTs be double-blind and that transfusion criteria should be applied consistently. Nonetheless, the rationale for ITT can be reversed in equivalence and non-inferiority trials where the finding of no difference is the objective of the research; thus, both ITT and AT analyses should be presented in these settings.
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Randomized Controlled Trial Comparative Study
Rationalizing blood transfusion in cardiac surgery: the impact of a red cell volume-based guideline on blood usage and clinical outcome.
Cardiac surgery is currently considered one of the heaviest users of red blood cells. An explanation may be found, in part, in considering the effect of the heavy clear fluid load associated with cardiopulmonary bypass. This may result in the artificial depression of haemoglobin concentration, overestimating the requirement for red cell transfusion if this is the sole parameter considered. To address this issue, we examined the impact of a red cell volume-based transfusion guideline on transfusion requirement. ⋯ In elective cardiac surgery patients, considering haemoglobin concentration alone may overestimate the requirement for red cell transfusion. More research is required to determine the impact of restrictive transfusion policies on clinical outcome following cardiac surgery.
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Analysis of haemoglobin (Hb) dilution after bleeding is a simple, inexpensive and non-invasive method to estimate blood loss. Blood volume is estimated, taking sex, weight and height into account. The Hb concentration before and after blood loss is analysed and, from the difference, the blood loss volume can be calculated assuming a normovolemic subject. Although widely used this method has never been validated. ⋯ The Hb dilution method underestimates the true blood loss by more than 30% after a moderate blood loss of approximately 10% of the total blood volume.