Vox sanguinis
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Practice misalignments can occur in any clinical trial investigating a pre-existing therapy that is typically adjusted based on clinical characteristics outside of the trial setting. To eliminate the heterogeneity in clinical practice, recent trials investigating titrated therapies have randomized patients to fixed-dose regimens without including a routine care control group receiving titrated therapy. In these trials, the normal relationships between clinically important characteristics and therapy titration are disrupted. ⋯ In addition, comparisons of trial arms with practice misalignments have limited interpretability and generalizability. In this review, we use examples from the literature to discuss how practice misalignments can impact the safety, results and conclusions of clinical trials. In addition, we discuss methods to characterize relationships between therapy titration and clinical characteristics and trial design strategies that may minimize practice misalignments.
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Multicenter Study
A pilot study of the possibility and the feasibility of haemoglobin dosing with red blood cells transfusion.
Red blood cell concentrates (RBCs) are the major blood component transfused. Although the haemoglobin content is variable, the transfusion dose is prescribed as units of red cell concentrates. Thus, by chance, large volume patients may receive a low haemoglobin dose and low volume patients may be transfused with haemoglobin-rich RBCs. The aim of this study was to evaluate whether the haemoglobin increment (grams per litre) in the patient can be predicted from the haemoglobin dose (in grams) transfused, with and without correction for estimated blood volume. If this is true, it may be possible to achieve the predicted transfusion outcome by selecting RBCs for each patient. ⋯ Post-transfusion increment in circulating haemoglobin can be predicted from the haemoglobin content of transfused cells, but knowledge of the patient's blood volume improves the accuracy of prediction. It may be feasible to select the high haemoglobin content RBC for patients with largest blood volume and vice versa.