A prospective observational study of the rapid detection of clinically-relevant plasma direct oral anticoagulant levels following acute traumatic injury.

In urgent clinical situations, such as trauma, urgent surgery or before thrombolysis, rapid quantification of direct oral anticoagulant plasma drug levels is warranted. Using the ClotPro® analyser, we assessed two novel viscoelastic tests for detection of clinically-relevant plasma drug levels in trauma patients. The ecarin clotting time was used to assess the plasma concentration of dabigatran and Russell´s viper venom clotting time to determine the plasma concentration of direct factor Xa inhibitors. In parallel, plasma concentrations were analysed using plasma-based chromogenic assays. A total of 203 simultaneous measurements were performed. Strong to very strong linear correlations were detected between ecarin clotting time and plasma concentration of dabigatran (r = 0.9693), and between Russell´s viper venom clotting time and plasma concentrations of apixaban (r = 0.7391), edoxaban (r = 0.9251) and rivaroxaban (r = 0.8792), all p < 0.001. An ecarin clotting time ≥ 189 seconds provided 100% sensitivity and 90% specificity for detecting plasma dabigatran concentrations ≥ 50 ng.ml-1 . Corresponding Russell´s viper venom clotting time cut-off values were ≥ 136 seconds for apixaban (80% sensitivity, 88% specificity), ≥ 168 seconds for edoxaban (100% sensitivity, 100% specificity) and ≥ 177 seconds for rivaroxaban (90% sensitivity, 100% specificity). Detection of drug levels ≥ 100 ng.ml-1 was also investigated: for dabigatran, an ecarin clotting time ≥ 315 seconds yielded 92% sensitivity and 100% specificity; while Russell´s viper venom clotting time cut-offs of 191, 188 and 196 seconds were calculated for apixaban (67% sensitivity, 88% specificity), edoxaban (100% sensitivity, 75% specificity) and rivaroxaban (100% sensitivity, 91% specificity), respectively. We have demonstrated strong positive correlations between plasma drug levels and clotting time values in the specific ClotPro assays. Cut-off values for detecting clinically-relevant drug levels showed high levels of sensitivity and specificity.

Protocolised thromboelastometric-guided haemostatic management in patients with traumatic brain injury: a pilot study.

Coagulopathy in patients with traumatic brain injury is associated with an increase in morbidity and mortality. Although timely and aggressive treatment of coagulopathy is of paramount importance, excessive transfusion of blood products has been linked with poor long-term outcomes in patients with traumatic brain injury. A point-of-care thromboelastometric-guided algorithm could assist in creating a more individually tailored approach to each patient. The aim of this study was to evaluate the feasibility of implementing a thromboelastometric-guided algorithm in centres that were formerly naïve to thromboelastometry. Hence, we developed such an algorithm and provided training to four centres across Europe to direct the haemostatic management of patients with severe traumatic brain injury. The primary outcome was adherence to the algorithm and timing of the availability of relevant results. Thirty-two patients were included in the study. Complete adherence to the algorithm was observed in 20 out of 32 cases. The availability of thromboelastometric results after hospital admission was reported significantly earlier than conventional coagulation tests (median (IQR [range]) 33 (20-40 [14-250]) min vs. 71 (51-101 [32-290]) min; p = 0.037). Although only 5 out of 32 patients had abnormalities of conventional coagulation tests, 21 out of 32 patients had a coagulopathic baseline thromboelastometric trace. Implementing a thromboelastometric-guided algorithm for the haemostatic therapy of traumatic brain injury is feasible in centres formerly naïve to this technology and may lead to more rapid and precise coagulation management. Further large-scale studies are warranted to confirm the results of this pilot trial and evaluate clinical outcomes.

Correction to: S(+)-ketamine : Current trends in emergency and intensive caremedicine.

Correction to: Wien Klin Wochenschr 2017 https://doi.org/10.1007/s00508-017-1299-3 The article S(+)-ketamine Current trends in emergency and intensive caremedicine, written by Helmut Trimmel, Raimund Helbok, Thomas Staudinger, Wolfgang Jaksch, Brigitte Messerer, Herbert Schöchl and Rudolf Likar, was ….

Reversal of dabigatran by intraosseous or intravenous idarucizumab in a porcine polytrauma model.

BACKGROUND: Idarucizumab is licensed to reverse dabigatran in life-threatening haemorrhage. Establishment of venous access can be challenging, and the intraosseous (IO) route is a potentially life-saving alternative. In this study, we compared the efficacy and safety of IO or intravenous (i.v.) idarucizumab for dabigatran reversal in a porcine polytrauma model. METHODS: Male pigs (n=21) received oral dabigatran etexilate (30 mg kg-1 bid) for 3 days. On the 4th day, animals received dabigatran infusion and were randomised 1:1:1 to receive IO saline (control), i.v. idarucizumab (60 mg kg-1), or IO idarucizumab (60 mg kg-1), or animals were included in a sham group (n=7). Study treatment was administered after polytrauma and the animals were monitored for 240 min, or until death. Coagulation status was monitored by thromboelastometry, thromboelastography, and thrombin measurements. RESULTS: Total blood loss was lowest in sham animals [521 (52) ml, P<0.01 vs all other groups], and comparable in the two idarucizumab groups [IO: 1085 (102) ml vs i.v.: 1142 (125) ml], and highest in the control group [4065 (557) ml, P<0.001 vs all other groups]. Survival to 240 min was 100% in the sham group and both idarucizumab groups, and 14% in the control group. IO and i.v. idarucizumab promptly normalised global coagulation assays and thrombin generation. Thromboelastography showed a strong correlation between dabigatran concentrations and R-time (R2=0.90 and 0.89) in idarucizumab-treated animals. CONCLUSIONS: Intravenous and intraosseous idarucizumab were comparable for reversing dabigatran in a porcine trauma model. Dabigatran reversal could be monitored using fully automated thromboelastography.

[Intensive care treatment of traumatic brain injury in multiple trauma patients : Decision making for complex pathophysiology]. / Intensivtherapie des Schädel-Hirn-Traumas beim Mehrfachverletzten : Entscheidungsfindung bei komplexer Pathophysiologie.

Traumatic brain injury (TBI) and hemorrhagic shock due to uncontrolled bleeding are the major causes of death after severe trauma. Mortality rates are threefold higher in patients suffering from multiple injuries and additionally TBI. Factors known to impair outcome after TBI, namely hypotension, hypoxia, hypercapnia, acidosis, coagulopathy and hypothermia are aggravated by the extent and severity of extracerebral injuries. The mainstays of TBI intensive care may be, at least temporarily, contradictory to the trauma care concept for multiple trauma patients. In particular, achieving normotension in uncontrolled bleeding situations, maintenance of normocapnia in traumatic lung injury and thromboembolic prophylaxis are prone to discussion. Due to an ongoing uncertainty about the definition of normotensive blood pressure values, a cerebral perfusion pressure-guided cardiovascular management is of key importance. In contrast, there is no doubt that early goal directed coagulation management improves outcome in patients with TBI and multiple trauma. The timing of subsequent surgical interventions must be based on the development of TBI pathology; therefore, intensive care of multiple trauma patients with TBI requires an ongoing and close cooperation between intensivists and trauma surgeons in order to individualize patient care.

Haemostatic profile of reconstituted blood in a proposed 1:1:1 ratio of packed red blood cells, platelet concentrate and four different plasma preparations.

The concept of haemostatic resuscitation implies early and high-volume plasma transfusion. We investigated the haemostatic profile of reconstituted whole blood prepared in a 1:1:1 ratio of blood, platelets and plasma. This consisted of packed red blood cells, platelet concentrate and four different plasma variants: fresh frozen; solvent-detergent; lyophilised quarantine; and lyophilised methylene blue-inactivated plasma. Haematocrit, platelet count, endogenous thrombin potential and coagulation factor activity were significantly lower in reconstituted blood compared with citrated whole blood (p < 0.01). Except for lyophilised methylene blue-inactivated plasma, no substantial differences between plasma variants in coagulation factor activity, endogenous thrombin potential and standard coagulation tests were observed. After reconstitution, haematocrit and platelet counts were slightly above recommended transfusion triggers, most thromboelastometry (ROTEM(®)) parameters were within the normal range and fibrinogen concentrations were between 1.57 g.l(-1) and 1.91 g.l(-1). Reconstitution of whole blood in a 1:1:1 ratio resulted in significant dilution of haematocrit and platelet count, but values remained above limits recommended by transfusion guidelines. Fibrinogen concentrations of reconstituted whole blood were also significantly reduced, and these were below the threshold value for supplementation recommended by recent guidelines.

Management of traumatic haemorrhage--the European perspective.

Trauma-induced coagulopathy represents a life-threatening complication in severely injured patients. To avoid exsanguination, rapid surgical bleeding control coupled with immediate and aggressive haemostatic treatment is mandatory. In most trauma centres, coagulation therapy is established with transfusion of high volumes of fresh frozen plasma. Due to logistic issues, only busy trauma facilities store pre-thawed plasma ready for immediate transfusion. Thus, substantial time delays have been reported between the first unit of red blood cells transfused and the administration of fresh frozen plasma. An alternative for rapid improvement of haemostatic capacity is purified coagulation factor concentrates. They contain a well-defined concentration of coagulation proteins, carry a low risk for transfusion-related lung injury and virus transmission, and are available for immediate use without the need for blood group matching. In some European trauma centres, treatment algorithms have been developed for the administration of coagulation factor concentrates based on visco-elastic test results.

Usefulness of standard plasma coagulation tests in the management of perioperative coagulopathic bleeding: is there any evidence?

Standard laboratory coagulation tests (SLTs) such as prothrombin time/international normalized ratio or partial thromboplastin time are frequently used to assess coagulopathy and to guide haemostatic interventions. However, this has been challenged by numerous reports, including the current European guidelines for perioperative bleeding management, which question the utility and reliability of SLTs in this setting. Furthermore, the arbitrary definition of coagulopathy (i.e. SLTs are prolonged by more than 1.5-fold) has been questioned. The present study aims to review the evidence for the usefulness of SLTs to assess coagulopathy and to guide bleeding management in the perioperative and massive bleeding setting. Medline was searched for investigations using results of SLTs as a means to determine coagulopathy or to guide bleeding management, and the outcomes (i.e. blood loss, transfusion requirements, mortality) were reported. A total of 11 guidelines for management of massive bleeding or perioperative bleeding and 64 studies investigating the usefulness of SLTs in this setting were identified and were included for final data synthesis. Referenced evidence for the usefulness of SLTs was found in only three prospective trials, investigating a total of 108 patients (whereby microvascular bleeding was a rare finding). Furthermore, no data from randomized controlled trials support the use of SLTs. In contrast, numerous investigations have challenged the reliability of SLTs to assess coagulopathy or guide bleeding management. There is actually no sound evidence from well-designed studies that confirm the usefulness of SLTs for diagnosis of coagulopathy or to guide haemostatic therapy.

Theoretical modelling of fibrinogen supplementation with therapeutic plasma, cryoprecipitate, or fibrinogen concentrate.

BACKGROUND: We aimed to create a theoretical tool to model the effect of three haemostatic agents containing fibrinogen (therapeutic plasma, cryoprecipitate, and fibrinogen concentrate) on the patient's plasma fibrinogen level. METHODS: A mathematical model was developed step-wise. The relationship between the amount of haemostatic agent and plasma fibrinogen level was plotted for each agent. A fibrinogen concentration simulator (FCS(amount)) was developed, where the amount of haemostatic agent was calculated from patient characteristics, agent characteristics, and target plasma fibrinogen level. Refinements were introduced so that (i) FCS(amount) would account for in vivo fibrinogen recovery, (ii) circulatory volume would not increase ad infinitum with increasing amounts, and (iii) red blood cells would be included in the simulation if haematocrit decreased below a certain level. A second FCS (FCS(level)) was created to calculate fibrinogen levels resulting from specified amounts of haemostatic agents. RESULTS: Fibrinogen concentration in haemostatic agents has a critical impact on their ability to increase patients' fibrinogen levels. If the target plasma fibrinogen level approaches the concentration of the fibrinogen source, the required amounts increase exponentially; it is impossible to achieve a target above the concentration of the fibrinogen source. CONCLUSIONS: We successfully developed two theoretical tools answering the questions: 'How much therapeutic plasma, cryoprecipitate, or fibrinogen concentrate would be needed to achieve a specified target fibrinogen level?' and 'What would be the resultant fibrinogen level for a specified amount of haemostatic agent?' The current tools are not intended for clinical application, but they are potentially useful for educational purposes.

Fibrinogen measurement in cardiac surgery with cardiopulmonary bypass: analysis of repeatability and agreement of Clauss method within and between six different laboratories.

Plasma fibrinogen concentration is important for coagulopathy assessment, and is most commonly measured using the Clauss method. Several factors, including device type and reagent, have been shown to affect results. The study objective was to evaluate performance and repeatability of the Clauss method and to assess differences between measurements performed during and after cardiopulmonary bypass (CPB), by testing plasma samples from patients undergoing cardiac surgery with CPB. Samples were collected from 30 patients before surgery, approximately 20 minutes before weaning from CPB, and 5 minutes after CPB and protamine. Fibrinogen concentration was determined using the Clauss method at six quality-controlled specialised laboratories, according to accredited standard operating procedures. Regarding within-centre agreement for Clauss measurement, mean differences between duplicate measurements were between 0.00 g/l and 0.15 g/l, with intervals for 95% limits of agreement for mean Bland-Altman differences up to 1.3 g/l. Regarding between-centre agreement, some mean differences between pairs of centres were above 0.5 g/l. Differences of up to ~2 g/l were observed with individual samples. Increased variability was observed between centres, with inter-class correlation values below 0.5 suggesting only fair agreement. There were no significant differences in fibrinogen concentration before weaning from CPB and after CPB for most centres and methods. In conclusion, considerable differences exist between Clauss-based plasma fibrinogen measured using different detection methods. Nevertheless, the similarity between measurements shortly before weaning from CPB and after CPB within centres suggests that on-pump measurements could provide an early estimation of fibrinogen deficit after CPB and thus guidance for haemostatic therapy.

[Perioperative coagulation management in multiple trauma patients based on viscoelastic test results]. / Gerinnungsmanagement bei Polytrauma mit Hilfe viskoelastischer Tests.

Exsanguination represents the most common and potentially preventable cause of death in major trauma patients. Rapid surgical intervention coupled with an early and aggressive hemostatic therapy not only results in survival benefits of coagulopathic trauma patients, but also reduces the incidence of complications and costs. Standard coagulation tests are not suitable to adequately characterize the complexity of trauma-induced coagulopathy (TIC). This fact has led to a renaissance of viscoelastic tests, such as rotational thromboelastometry (ROTEM®) and thrombelastography (TEG®), which can be used as point-of-care monitors. In some trauma centers treatment algorithms have been developed, where hemostatic therapy is based on viscoelastic test results. Shock and tissue trauma activate profibrinolytic pathways which in turn result in premature dissolution of formed clots. Tranexamic acid rapidly and inexpensively blocks hyperfibrinolysis. ROTEM®/TEG® measurements revealed that diminished clot strength is associated with an increased bleeding tendency. Depending on the underlying cause, administration of fibrinogen concentrate and/or platelet concentrate administration improves clot firmness. Thrombin generation is initially less compromised and can be improved by the administration of plasma, prothrombin complex concentrate, or with restrictiveness by recombinant activated factor VII.

The role of fibrinogen in trauma-induced coagulopathy.

Fibrinogen plays an essential role in clot formation and stability. Importantly it seems to be the most vulnerable coagulation factor, reaching critical levels earlier than the others during the course of severe injury. A variety of causes of fibrinogen depletion in major trauma have been identified, such as blood loss, dilution, consumption, hyperfibrinolysis, hypothermia and acidosis. Low concentrations of fibrinogen are associated with an increased risk of diffuse microvascular bleeding. Therefore, repeated measurements of plasma fibrinogen concentration are strongly recommended in trauma patients with major bleeding. Recent guidelines recommend maintaining plasma fibrinogen concentration at 1.5-2 g/l in coagulopathic patients. It has been shown that early fibrinogen substitution is associated with improved outcome.

A novel coagulation assay incorporating adherent endothelial cells in thromboelastometry.

Following vascular injury or activation, endothelial cells (ECs) participate in the modulation of haemostasis and fibrinolysis. Viscoelastic tests (VETs) are a potent bedside monitoring tool that reports haemostatic parameters in real time. However, VETs neglect the influence of the surrounding endothelium. Our aim was therefore to establish an assay that incorporates ECs in a whole blood VET and to assess the impact of ECs on coagulation parameters. Outgrowth endothelial cells (OECs) and human umbilical vein endothelial cells (HUVECs) were seeded onto microbeads to create transferable EC-microcarriers. Microbeads were then added to citrated whole blood in the measurement cup of a thromboelastometry device (ROTEM). After the addition of CaCl2 (star-TEM®) to the blood sample (NATEM assay), standard ROTEM parameters were analysed. Scanning electron microscopy (SEM) was carried out to visualise the interactions of the beads, whole blood components and the ROTEM pin after clotting. SEM showed that the added microbeads were effectively incorporated into the final blood clot. In the presence of activated ECs, the clotting time (CT) of the blood was shortened fourfold compared to that in uncoated control beads. A significant reduction in CT was also observed in the presence of unstimulated ECs. Interestingly, CT was also reduced by the addition of purified EC culture supernatant. CT shortening was prevented by incubating the supernatant with an inhibiting antibody against tissue factor (TF). Our findings demonstrate that ECs can be incorporated into a ROTEM assay via coated microbeads, and whole blood clotting initiation is accelerated by non-activated and activated ECs.

Hyperfibrinolysis is common in out-of-hospital cardiac arrest: results from a prospective observational thromboelastometry study.

BACKGROUND: Cardiocirculatory arrest (CCA) activates procoagulant pathways. It has also been reported to inhibit fibrinolysis, resulting in fibrin deposition and further impairment of blood flow. Until now, no studies have used whole-blood viscoelastic tests to characterize coagulation and the impact of fibrinolysis in out-of-hospital cardiac arrest (OHCA). METHODS: Patient with established OHCA who underwent cardiopulmonary resuscitation (CPR) were enrolled. Blood samples were obtained immediately after placement of an intravenous line at the scene, for full blood cell count, standard coagulation tests and rotational thromboelastometric (ROTEM(®)) analyses. Patients with return of spontaneous circulation (ROSC) were compared to non-ROSC patients. RESULTS: Fifty-three patients (median age 67 years, interquartile range: 56-73 years) were included in the study. ROSC was established in 25 patients. Prothrombin time index (PTI) was significantly lower and activated partial thromboplastin time (aPTT) was significantly prolonged in non-ROSC patients compared to ROSC patients. Clotting time (CT) in the extrinsically activated ROTEM test (EXTEM) was significantly longer in non-ROSC versus ROSC patients. For the remaining EXTEM parameters, there were no significant differences between ROSC and non-ROSC patients. Hyperfibrinolysis (maximum lysis>15% according to ROTEM test results) was observed in 19 patients (35.8%). There was no difference between ROSC and non-ROSC patients in the incidence of hyperfibrinolysis. CONCLUSIONS: PTI, aPTT and EXTEM CT revealed significant differences between ROSC and non-ROSC patients. Hyperfibrinolysis according to ROTEM test results was much more common than previously assumed. Routine use of fibrinolytic therapy in all patients with prolonged CPR cannot therefore be recommended.

Trauma-associated hyperfibrinolysis.

Trauma-induced coagulopathy (TIC) has been considered for a long time as being due to depletion of coagulation factors secondary to blood loss, dilution and consumption. Dysfunction of the remaining coagulation factors due to hypothermia and acidosis is assumed to additionally contribute to TIC. Recent data suggest that hyperfibrinolysis (HF) represents an additional important confounder to the disturbed coagulation process. Severe shock and major tissue trauma are the main drivers of this HF. The incidence of HF is still speculative. According to visco-elastic testing of trauma patients upon emergency room admission, HF is present in approximately 2.5-7% of all trauma patients. However, visco-elastic tests provide information on severe forms of HF only. Occult HF seems to be much more common but diagnosis is still challenging. Results from a recent randomized, placebo-controlled trial suggest that the early treatment of trauma patients with tranexamic acid may result in a significant reduction of trauma-associated mortality.

Sedation training using a human patient simulator.

High-fidelity simulation uses simulators that combine all of the physiological and pharmacological responses of a human in a manikin. These simulators change and respond to the users and trainees. Using simulators for teaching sedation in the field of gastroenterology unifies all the advantages of manikins. To understand the pharmacological and pharmacodynamical principles of drugs used for sedation in different clinical scenarios, such as cardiopulmonary diseases, a high-fidelity simulator is extremely useful. Respiratory complications and airway problems are the main side effects when using sedatives. To overcome these problems, exercise of precautionary measures are highly demanded to avoid hazards. High-fidelity simulation is increasingly being used for the development of crisis resource management. There are still limitations in using simulators for education and training. At present, applying simulation for teaching is expensive. The start-up costs and the expenses for instructors and technicians are high. Moreover, no direct evidence has demonstrated that simulation training improves actual patient safety outcome and, therefore, a lot of research in this field remains to be done. Even so, confidence is growing in the validity of medical simulation as the training tool of the future.

Use of rotation thromboelastometry (ROTEM) to achieve successful treatment of polytrauma with fibrinogen concentrate and prothrombin complex concentrate.

Goal-directed coagulation therapy is essential in the management of trauma patients with severe bleeding. Due to the complex nature of coagulation disorders in trauma, a quick and reliable diagnostic tool is essential. We report a severely injured multiple trauma patient who received haemostatic therapy with coagulation factor concentrates, guided by rotational thromboelastometry (ROTEM). Initial therapy consisted of fibrinogen concentrate (Haemocomplettan P), as maximum clot firmness in the ROTEM analyses was low, whereas clotting time was normal. Later on, prothrombin complex concentrate was given to optimise thrombin generation. This approach enabled extended emergency hemihepatectomy to be performed without using fresh frozen plasma. As the EXTEM maximum clot firmness showed good clot quality, no platelets were transfused despite low platelet counts. This case shows the potential success of treatment using both fibrinogen concentrate and prothrombin complex concentrate, not only in restoring haemostasis but also in minimising requirement for transfusion of allogeneic blood products.

[Coagulation management in the treatment of multiple trauma]. / Gerinnungsmanagement bei der Polytraumaversorgung.

In recent years a new understanding of trauma-associated hemorrhaging and trauma-induced coagulopathy has been achieved. This coagulopathy is multifactorial with the predominant mechanisms being tissue trauma, shock and hypoperfusion which can lead to hyperfibrinolysis by activation of the endothelium. Routinely tested coagulation parameters, such as prothrombin time and partial thromboplastin time, are frequently employed for decision making but remain problematic as they do not give any information on clot stability, lysis or platelet function. Thrombelastometry seems to be a useful alternative. A pro-active anticipatory approach is required for a successful outcome to be achieved as rescue correction is more difficult than prevention. While the pathophysiological conception of causal relationship of the mentioned therapeutic options is conclusive, an evidence-based validation by randomized controlled studies is mostly lacking. The emergency and anesthesiological concept of damage control resuscitation consists of limiting volume therapy with crystalloids and colloids to reach a mean arterial pressure > or =65 mmHg (higher for head injuries), active (re-)warming management, the prevention of a pH< or =7.2 and a base excess (BE) < or =-6 mmol/l. The early and sufficient application of hemostatic drugs is essential. Because erythrocytes play a substantial role in the coagulation process, hemoglobin (Hb) values of around 6. 2 mmol/l (10 g/dl) and/or a hematocrit of 30% should be strived for when massive non-arrested hemorrhaging occurs. After severe multiple trauma a fibrinogen deficit develops and must be adequately compensated. If coagulation therapy is carried out using fresh frozen plasma sufficient quantities (20-30 ml/kgBW) must be administered to correspondingly raise the coagulation factors. Prothrombin complex concentrates can be helpful to optimize thrombin generation during severe hemorrhaging. Because hyperfibrinolysis occurs more often than previously assumed during severe trauma, an anti-fibrinolytic therapy should be used especially for patients with an instable circulation. The platelet count should not go below 100,000/microl when hemorrhaging occurs after multiple trauma. For thrombocytopathic patients with diffuse bleeding desmopressin (DDAVP) is a therapeutic option and the "off label" use of recombinant activated factor VIIa (rFVIIa) remains an option for individual situations with stringent indications and when the above named measures to optimize the coagulation situation have been taken.

[Preoperative evaluation of the bleeding history. Recommendations of the working group on perioperative coagulation of the Austrian Society for Anaesthesia, Resuscitation and Intensive Care]. / Präoperative Blutungsanamnese. Empfehlungen der Arbeitsgruppe perioperative Gerinnung der Osterreichischen Gesellschaft für Anästhesiologie, Reanimation und Intensivmedizin.

Unexpected bleeding in the perioperative period is largely caused by impaired inherited or drug-induced primary haemostasis. Standard tests for plasma coagulation are predominantly employed to gauge the risk of bleeding. In accordance with several reports the subcommittee for perioperative coagulation (AGPG) of the Austrian Society of Anaesthesia, Resuscitation and Intensive Care (OGARI) recommends the use of a standardised questionnaire to detect an increased risk of bleeding. Accordingly, healthy patients of the American Society of Anesthesiologists (ASA) grades I and II without any suspicion of impaired haemostasis who are scheduled for procedures without expected transfusion requirements, need no standard tests for coagulation. In all other patients (including patients taking medication affecting coagulation, or patients who are unable to provide adequate information) platelet count, platelet function, aPTT, PT, and fibrinogen levels should be assessed.