Background and Objectives
In Caucasians, fetal/neonatal alloimmune thrombocytopenia (FNAIT) is most commonly due to maternal HPA‐1a antibodies. HPA‐1a typing followed by screening for anti‐HPA‐1a ...antibodies in HPA‐1bb women may identify first pregnancies at risk. Our goal was to review results from previous published studies to examine whether the maternal antibody level to HPA‐1a could be used to identify high‐risk pregnancies.
Materials and Methods
The studies included were categorized by recruitment strategies: screening of unselected pregnancies or samples analyzed from known or suspected FNAIT patients.
Results
Three prospective studies reported results from screening programmes, and 10 retrospective studies focused on suspected cases of FNAIT. In 8 studies samples for antibody measurement, performed by the monoclonal antibody immobilization of platelet antigen (MAIPA) assay, and samples for determining fetal/neonatal platelet count were collected simultaneously. In these 8 studies, the maternal antibody level correlated with the risk of severe thrombocytopenia. The prospective studies reported high negative predictive values (88–95%), which would allow for the use of maternal anti‐HPA‐1a antibody level as a predictive tool in a screening setting, in order to identify cases at low risk for FNAIT. However, due to low positive predictive values reported in prospective as well as retrospective studies (54–97%), the maternal antibody level is less suited for the final diagnosis and for guiding antenatal treatment.
Conclusion
HPA‐1a antibody level has the potential to predict the severity of FNAIT.
Abstract Patients with hypoproliferative thrombocytopenia are at an increased risk for hemorrhage and alloimmunization to platelets. Updated guidance for optimizing platelet transfusion therapy is ...needed as data from recent pivotal trials have the potential to change practice. This guideline, developed by a large international panel using a systematic search strategy and standardized methods to develop recommendations, incorporates recent trials not available when previous guidelines were developed. We found that prophylactic platelet transfusion for platelet counts less than or equal to 10 × 109 /L is the optimal approach to decrease the risk of hemorrhage for patients requiring chemotherapy or undergoing allogeneic or autologous transplantation. A low dose of platelets (1.41 × 1011 /m2 ) is hemostatically as effective as higher dose of platelets but requires more frequent platelet transfusions suggesting that low-dose platelets may be used in hospitalized patients. For outpatients, a median dose (2.4 × 1011 /m2 ) may be more cost-effective to prevent clinic visits only to receive a transfusion. In terms of platelet products, whole blood–derived platelet concentrates can be used interchangeably with apheresis platelets, and ABO-compatible platelet should be given to improve platelet increments and decrease the rate of refractoriness to platelet transfusion. For RhD-negative female children or women of child-bearing potential who have received RhD-positive platelets, Rh immunoglobulin should probably be given to prevent immunization to the RhD antigen. Providing platelet support for the alloimmunized refractory patients with ABO-matched and HLA-selected or crossmatched products is of some benefit, yet the degree of benefit needs to be assessed in the era of leukoreduction.
Blood transfusion Allard, Shubha
Medicine (Abingdon. 1995, UK ed.),
03/2009, Letnik:
37, Številka:
3
Journal Article
Recenzirano
Abstract The term ‘blood transfusion’ generally refers to the therapeutic use of blood and components (red cells, platelets, fresh frozen plasma and cryoprecipitate). Careful donor selection and ...stringent testing by the blood service is required to ensure a safe blood supply. Blood transfusion may be essential for many clinical treatments where it can be life saving. However, donated blood is a limited resource and hospital blood transfusion practice must focus on ensuring safe and appropriate use. Clinical guidelines are essential in all specialities using blood and components supported by education and training with regular audit of practice. Particular emphasis is required on accurate patient identification through the whole transfusion process from taking the initial blood sample, laboratory testing and transfer of blood to clinical areas to the final bedside check prior to transfusion to minimize errors. The reporting and monitoring of all adverse events in relation to blood transfusion via national haemovigilance schemes has highlighted key areas for action resulting in improved transfusion safety. Transfusion medicine must be practiced within a strict regulatory framework and, in particular, the European Union (EU) blood directives have had far-reaching implications for the UK blood services and for hospital transfusion laboratories.
ObjectivesTo evaluate the cost-effectiveness of routine use of cell salvage during caesarean section in mothers at risk of haemorrhage compared with current standard of care.DesignModel-based ...cost-effectiveness evaluation alongside a multicentre randomised controlled trial. Three main analyses were carried out on the trial data: (1) based on the intention-to-treat principle; (2) based on the per-protocol principle; (3) only participants who underwent an emergency caesarean section.Setting26 obstetric units in the UK.Participants3028 women at risk of haemorrhage recruited between June 2013 and April 2016.InterventionsCell salvage (intervention) versus routine care without salvage (control).Primary outcome measuresCost-effectiveness based on incremental cost per donor blood transfusion avoided.ResultsIn the intention-to-treat analysis, the mean difference in total costs between cell salvage and standard care was £83. The estimated incremental cost-effectiveness ratio (ICER) was £8110 per donor blood transfusion avoided. For the per-protocol analysis, the mean difference in total costs was £92 and the ICER was £8252. In the emergency caesarean section analysis, the mean difference in total costs was £55 and the ICER was £13 713 per donor blood transfusion avoided. This ICER is driven by the increased probability that these patients would require a higher level of postoperative care and additional surgeries. The results of these analyses were shown to be robust for the majority of deterministic sensitivity analyses.ConclusionsThe results of the economic evaluation suggest that while routine cell salvage is a marginally more effective strategy than standard care in avoiding a donor blood transfusion, there is uncertainty in relation to whether it is a less or more costly strategy. The lack of long-term data on the health and quality of life of patients in both arms of the trial means that further research is needed to fully understand the cost implications of both strategies.Trial registration number ISRCTN66118656.
The massive-transfusion concept was introduced to recognize the dilutional complications resulting from large volumes of packed red blood cells (PRBCs). Definitions of massive transfusion vary and ...lack supporting clinical evidence. Damage-control resuscitation regimens of modern trauma care are targeted to the early correction of acute traumatic coagulopathy. The aim of this study was to identify a clinically relevant definition of trauma massive transfusion based on clinical outcomes. We also examined whether the concept was useful in that early prediction of massive transfusion requirements could allow early activation of blood bank protocols.
Datasets on trauma admissions over a 1 or 2-year period were obtained from the trauma registries of five large trauma research networks. A fractional polynomial was used to model the transfusion-associated probability of death. A logistic regression model for the prediction of massive transfusion, defined as 10 or more units of red cell transfusions, was developed.
In total, 5,693 patient records were available for analysis. Mortality increased as transfusion requirements increased, but the model indicated no threshold effect. Mortality was 9% in patients who received none to five PRBC units, 22% in patients receiving six to nine PRBC units, and 42% in patients receiving 10 or more units. A logistic model for prediction of massive transfusion was developed and validated at multiple sites but achieved only moderate performance. The area under the receiver operating characteristic curve was 0.81, with specificity of only 50% at a sensitivity of 90% for the prediction of 10 or more PRBC units. Performance varied widely at different trauma centers, with specificity varying from 48% to 91%.
No threshold for definition exists at which a massive transfusion specifically results in worse outcomes. Even with a large sample size across multiple trauma datasets, it was not possible to develop a transportable and clinically useful prediction model based on available admission parameters. Massive transfusion as a concept in trauma has limited utility, and emphasis should be placed on identifying patients with massive hemorrhage and acute traumatic coagulopathy.
BackgroundFew studies have characterised massive blood transfusion (MBT) practice in UK trauma. This study describes the Trauma Audit and Research Network experience of MBT over a 4-year period, and ...examines variables predictive of MBT and mortality following MBT.MethodsProspectively collected data between 2005 and 2009 from the Trauma Audit and Research Network database were analysed. MBT incidence was examined, and patient characteristics, blood component usage and mortality compared to non-MBT patients. Clinical and injury features predictive of massive transfusion, and risk factors predictive of death in MBT, were analysed using multivariate logistic regression.Results157 patients (0.4%) received MBT, with a mortality rate of 40.3%. MBT patients were younger, more likely to be male and to have sustained more severe trauma (median age 39.2 years, median Injury Severity Score 27, 78% male, p<0.01). No patients received platelets and fresh frozen plasma (FFP) in 1:1 ratios with packed red cells. Multivariate analysis showed: age, admission pulse rate, systolic blood pressure, and injury type; thoracic, abdominal, pelvis, were significant predictors of MBT. Injury Severity Score and admission pulse rate were also independent predictors of death in MBT, but level of platelet and FFP use were not found to be statistically significant.ConclusionMBT is a rare event with high mortality in UK trauma. Haemostatic resuscitation is not currently practiced in the UK and the authors were unable to show that FFP and platelet use were significant predictors of survival in MBT.
An important cause of maternal morbidity and direct maternal death is obstetric haemorrhage at caesarean section. Concerns regarding allogeneic blood safety, limited blood supplies and rising health ...costs have collectively generated enthusiasm for the utility of methods intended to reduce the use of allogeneic blood transfusion in cases of haemorrhage at caesarean section. This can be achieved by intraoperative cell salvage (IOCS). The aim of this review is to summarize and examine the evidence for the efficacy of IOCS during caesarean section, in women at risk of haemorrhage, in reducing the need for allogeneic blood transfusion.
The majority of the evidence currently available is from case reports and case series. Although this evidence appears to support the use of IOCS in obstetrics, strong clinical evidence or economic effectiveness from clinical trials are essential to support the routine practice of IOCS in obstetrics.
Current evidence is limited to reported case series and two small controlled studies. Overall, IOCS may reduce the need for allogeneic blood transfusions during caesarean section. Future large randomized trials are required to assess effectiveness, cost effectiveness and safety. The results of the current ongoing SALVO (A randomised controlled trial of intra-operative cell salvage during caesarean section in women at risk of haemorrhage) trial will shed light on these aspects.
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