Rotation thromboelastometry (ROTEM®) stability and reproducibility over time

Background: Thromboelastometry is a whole blood assay performed to evaluate the viscoelastic properties during blood clot formation and lysis. Rotation thromboelastography (ROTEM®, Pentapharm GmbH, Munich, Germany) has overcome some of the limitations of classic thromboelastography. So far, no clinical validation on reproducibility (inter- and intra-assay variability) and sample stability over time has been published. Methods: To evaluate the pre-analytic aspects, sample stability over time was assessed in 48 patients in eight age groups. Citrated blood was stored at room temperature. Tests measured every 30min from T 0min up to T 120min on two ROTEM® devices were INTEM (ellagic acid activated intrinsic pathway), EXTEM (tissue factor-triggered extrinsic pathway) and FIBTEM (with platelet inhibitor (cytochalasin D) evaluating the contribution of fibrinogen to clot formation). Precision by intra- and inter-assay variability was evaluated at two points of time in 10 volunteers. Finally, reference intervals and effect of age and sex were evaluated. Results: Blood was stable over 120min and no significant differences in ROTEM® results were found. Maximum clot firmness measurements had a coefficient of variation of ≪3% for EXTEM, ≪5% for INTEM and ≪6% for FIBTEM. For clot formation time, the coefficient of variation was ≪4% for EXTEM and ≪3% for INTEM. Coefficient of variation for angle alpha was ≪3% for EXTEM and ≪6% for INTEM. The coefficient of variation for clotting time was ≪15% for both EXTEM and INTEM. Small but significant differences between ROTEM® devices were found for maximum clot firmness in FIBTEM and INTEM as well as clot formation time and alpha angle in INTEM. Conclusions: ROTEM® yields stable results over 120min with a minimal variability on the same ROTEM® device. However, small but significant differences between ROTEM® devices were observed. Analysis should be performed on the same ROTEM® device if small differences are of importance for treatmen

Ein WHO Konzept – Patient Blood Management

Blood transfusions are in general considered as lifesaving. Current data and evidence show, that blood transfusions are associated with increased morbidity and mortality, and this apparently dose-dependent. Basic research and results from randomized controlled trials show a causal relationship between blood transfusion and adverse outcome. Based on the current state of knowledge it has to be questioned that blood transfusions are "life-saving" as patients are exposed to an increased risk of disease or death. Furthermore, blood transfusions are more costly than previously assumed. For these reasons novel approaches in the treatment of anemia and bleeding are needed. Patient Blood Management (PBM) allows reduction of transfusion rates by correcting anemia by stimulating erythropoiesis, minimizing perioperative blood loss and optimizing the physiological tolerance of anemia. In 2010 the World Health Organization has claimed PBM to be considered as golden standard. PBM reduces morbidity and mortality by lowering the excessive use of blood transfusions. This concept has partially and successfully been implemented in the University Hospital Balgrist in Zurich

Transfusion strategy in multiple trauma patients

PURPOSE OF REVIEW To point out the tolerance of anemia, the possible use of alternatives to allogeneic blood products as well as the pathophysiological effects of transfusions in the context of multiple trauma patients. RECENT FINDINGS Restrictive transfusion triggers are beneficial for patient outcome in trauma.The actual European Trauma Treatment Guidelines suggest the use of point-of-care devices, the use of transfusion algorithms and factor concentrates to control coagulopathy. The use of high ratios of plasma to red blood cells to improve survival has been shown to suffer from a time-dependent survival bias. In massive bleeding, factor-based treatment of coagulopathy is feasible and preferable to plasma transfusion, if available. In nonmassive bleeding, allogeneic transfusion of blood products increases the appearance of serious adverse events and mortality and should be avoided unless clearly indicated. SUMMARY Transfusion in trauma has to be an individual decision for a specific patient, not for a specific laboratory value. Transfusion management must aim at reducing or even avoiding the use of allogeneic blood products. This may lead to a new gold standard with cost reduction and amelioration of outcome of major trauma patients

Resuscitation and transfusion management in trauma patients: emerging concepts

PURPOSE OF REVIEW: Severe trauma is associated with hemorrhage, coagulopathy and transfusion of blood and blood products, all associated with considerable mortality and morbidity. The aim of this review is to focus on resuscitation, transfusion strategies and the management of bleeding in trauma as well as to emphasize on why coagulation has to be monitored closely and to discuss the rationale of modern and future transfusion strategies. RECENT FINDINGS: Coagulopathy and uncontrolled bleeding remain leading causes of death in trauma, lead to blood transfusions and increased mortality as it has been recently shown that blood transfusion per se results in an adverse outcome. In the last years, damage control resuscitation, a combination of permissive hypotension, hemostatic resuscitation and damage control surgery, has been introduced to treat severely traumatized patients in hemorrhagic shock. Goals of treatment in trauma patients remain avoiding metabolic acidosis, hypothermia, treating coagulopathy and stabilizing the patient as soon as possible. The place of colloids and crystalloids in trauma resuscitation as well as the role of massive transfusion protocols with a certain FFP : RBC ratio and even platelets have to be reevaluated. SUMMARY: Close monitoring of bleeding and coagulation in trauma patients allows goal-directed transfusions and thereby optimizes the patient's coagulation, reduces the exposure to blood products, reduces costs and may improve clinical outcome

Point of care and factor concentrate-based coagulation algorithms

In the last years it has become evident that the use of blood products should be reduced whenever possible. There is increasing evidence regarding serious adverse events, including higher mortality and morbidity, related to transfusions. The use of point of care (POC) devices integrated in algorithms is one of the important mechanisms to limit blood product exposure. Any type of algorithm, especially the POC-based ones, allows goal-directed transfusions of blood products and even better targeted factor concentrate substitutions. Different types of algorithms in different surgical settings (cardiac surgery, trauma, liver surgery etc.) have been established with growing interest in their use as they offer objective therapy for management and reduction of blood product use. The use of POC devices with evidence-based algorithms is important in the bleeding patient independent of its origin (traumatic vs. surgical). The use of factor concentrates compared to the classical blood products can be cost-saving, beneficial for the patient, and in agreement with the WHO-requested standard of care. The empiric and uncontrolled use of blood products such as fresh frozen plasma, red blood cells, and platelets without POC monitoring should no longer be followed with regard to actual evidence in literature. Furthermore, the use of factor concentrates may provide better outcomes and potential for cost saving

Accuracy of non-invasive continuous total hemoglobin measurement by Pulse CO-Oximetry in severe traumatized and surgical bleeding patients

The Masimo Radical-7 Pulse CO-Oximeter (Masimo Corp., USA) non-invasively computes hemoglobin concentration (SpHb). SpHb was compared to Co-Oximeter readings (CoOxHb) of arterial samples in surgery patients of the emergency department. Forty-six patients were enrolled. The Masimo R1 25L (revision F and G) adult adhesive sensor was attached to the ring finger of the arterially cannulated hand. Before start, every 30 min during surgery and in the case of severe bleeding SpHb and CoOxHb values were documented. SpHb and post hoc adjusted SpHb (AdSpHb) values were analyzed. Linear regression analysis and Bland-Altman plot for agreement were performed. The detection failure rate of SpHb was 24.5 %. CoOxHb and SpHb showed a strong correlation (r = +0.81), but agreement was moderate [bias (LOA) of -0.6 (-3.0; +1.9)] g/dl. Positive and negative predicted value was 0.49 and 0.69. Exclusion of changes of CoOxHb values ≤1 g/dl resulted in a positive and negative predictive value of 0.66 and 1.00. Post hoc adjustment of the SpHb (AdSpHb) improved linear correlation of CoOxHb and AdSpHb [r = +0.90 (p < 0.001)] but less the agreement [bias (LOA) of CoOxHb and AdSpHb = -0.1 (-2.1/+1.9) g/dl]. SpHb agreed only moderately with CoOxHb values and predicted decreases of CoOxHb only if changes of SpHb ≤ 1.0 g/dl were excluded. The detection failure rate of SpHb was high. At present, additional refinements of the current technology are necessary to further improve performance of non-invasive hemoglobin measurement in the clinical setting