Anaesthesia
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Almost 30,000 cardiopulmonary bypass operations are performed in the UK every year, consuming a considerable portion of the UK blood supply. Each year, in cardiac surgery, 90% of blood products are used by only 10% of patients, and over the past 25 years, much innovation and research has gone into improving peri-operative diagnosis and therapy for these patients. Visco-elastic tests performed at the bedside, with modifications to allow direct quantification of fibrinogen levels, are probably the biggest advancement. ⋯ Factor concentrates, however, carry significant risks, particularly unnecessary donor exposures, potential selective over-correction of partial deficiencies and the possibility that the postoperative risk of venous thromboembolism is increased; as yet there are no data on risk-benefit analysis. There are a number of promising drugs used in topical haemostasis, but the requirement to apply these before major bleeding is manifest limits their use considerably. Hyperfibrinolysis is less important than in the past due to the wide spread adoption of antifibrinolytic agents and close intra-operative monitoring of heparin effect.
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The haemostatic management of major obstetric haemorrhage remains challenging, and current published guidance relies heavily on experience from the non-pregnant population and expert opinion. In recent years, an interest in the implications of relative hypofibrinogenaemia, point-of-care monitoring of coagulation abnormalities, and the potential to give goal-directed therapy to correct coagulopathies, have created the possibility of significantly challenging and changing guidance. ⋯ This review examines areas such as possible intervention points, describes evidence for over-transfusion of fresh frozen plasma in some situations and challenges conventional thinking on formulaic management. It also examines the rationale for other therapeutic options, including fibrinogen concentrate and tranexamic acid.
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Red cell transfusion therapy is a common treatment modality in contemporary medical practice. Although blood collection and administration is safer and more efficient than ever before, red cells undergo multiple metabolic and structural changes during storage that may compromise their functionality and viability following transfusion. ⋯ In the current review, we begin with an in-depth overview of the pathophysiological mechanisms underlying red cell storage, with a focus on altered metabolism, oxidative stress and red cell membrane damage. We proceed to review the current state of evidence on the clinical relevance and consequences of the red cell storage lesion, while discussing the strengths and limitations of clinical studies.
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Review Comparative Study
A performance comparison of the paediatric i-gel(™) with other supraglottic airway devices.
We performed a review of published literature comparing the i-gel with other supraglottic airway devices in children. Sixty-two articles were identified following a literature search; we included data from 14 randomised controlled trials and eight observational studies that compared i-gel sizes 1-2.5 with other commonly used, equivalently-sized, devices. The primary outcome in most studies was oropharyngeal leak pressure. ⋯ Insertion success rate, gastric tube placement and complications were similar for all the devices. Seven of the eight observational studies measured average oropharyngeal leak pressures of 20-27 cmH2O and all had first-time insertion success rates exceeding 90%. We conclude that the i-gel is at least equivalent to other supraglottic airway devices currently available for use in children, and may enable a higher oropharyngeal leak pressure and an improved fibreoptic view of the glottis.
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Over the last 10 years, the management of major haemorrhage in trauma patients has changed radically. This is mainly due to the recognition that many patients who are bleeding when they come in to the emergency department have an established coagulopathy before the haemodilution effects of fluid resuscitation. This has led to the use of new terminology: acute traumatic coagulopathy, acute coagulopathy of trauma shock or trauma-induced coagulopathy. ⋯ While there is as yet no universally accepted assay or definition, many experts use prolongation of the prothrombin time to indicate that there is, indeed, a coagulopathy. Hypoxia, acidosis and hypothermia and hormonal, immunological and cytokine production, alongside consumption and blood loss, and the dilutional effects of resuscitation may occur to varying extents depending on the type of tissue damaged, the type and extent of injury, predisposing to, or amplifying, activation of coagulation, platelets, fibrinolysis. These are discussed in detail within the article.