Best practice & research. Clinical anaesthesiology
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Unexplained intra-operative coagulopathies continue to be a diagnostic and therapeutic dilemma. The pathophysiology behind unexplained intra-operative coagulopathies is of great variety and complexity (pre-existing coagulopathies, dilutional coagulopathy, interactions of medications, etc.). We have shown in prospective studies that patients undergoing elective surgery who develop 'unexplained' intra-operative bleeding have significantly less F. ⋯ At least one proof-of-principle landmark study suggests that such patients benefit from treatment with F. XIII early intra-operatively. This new concept helps to explain the pathophysiology behind unexplained intra-operative coagulopathies and thus allows for corresponding treatment strategies.
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Perioperative coagulation monitoring is the rational diagnostic basis for pro- and anti-thrombotic interventions in patients undergoing emergency and elective surgery. The main goal of perioperative monitoring of haemostasis is to increase safety of patients undergoing surgical procedures. Currently, there is a change in paradigm with (1) increasing implementation of evidence-based approach to preoperative patient evaluation with laboratory coagulation testing secondary to the results of the standardised bleeding history and (2) awareness of the limitations of routine coagulation tests to guide coagulation management in massive bleeding. ⋯ This innovative methodology triggers a trend towards an 'early goal-directed coagulation management' focussing on potent coagulation factor concentrates. Practicability, cost-effectiveness, safety and--above all--growing scientific evidence support this concept, and lively discussions among anaesthesiologists and various medical disciplines may help to refine it. The present review focusses on the following key issues of perioperative coagulation monitoring: standardised bleeding history, routine coagulation testing, visco-elastic point-of-care coagulation testing, heparin monitoring, and platelet function testing.
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Perioperative coagulopathy impacts on patient outcome by influencing final blood loss and transfusion requirements. The recognition of pre-existing disturbances and the basic understanding of the principles of and dynamic changes of haemostasis during surgery are pre-conditions for safe patient management. The newly developed cellular model of coagulation facilitates the understanding of coagulation, thereby underscoring the importance of the tissue factor-bearing cell and the activated platelet. ⋯ Recent data from studies using viscoelastic coagulation studies confirm the central role of fibrinogen in stable clot formation and provide essential knowledge about its changes during blood loss and fluid administration. Besides early decrease in clot firmness during mild-to-moderate dilution, profound dilution results in a critical decrease in thrombin generation as well as a reduction in numbers and function of platelets. Although our knowledge of perioperative coagulopathy has dramatically increased over the past few years, several questions such as critical thresholds for fibrinogen, platelets, impact of FXIII and TAFI remain unanswered and need to be investigated further.
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One of the greatest disappointments associated with a successful surgical procedure is a thrombotic or thrombo-embolic complication in the postoperative period. Morbidity and mortality of the perioperative period are related, to a relevant degree, to perioperative thrombo-embolic events. Ranging from simple deep venous thrombosis to pulmonary embolism or arterial thrombosis, this class of complication invariably increases length of hospital stay or may result in mortality. The purpose of this review is to identify the procedures and patient populations noted to have thrombophilia in the postoperative period, link the changes in circulating and in situ haematological/biochemical substrates most likely responsible for morbidity, identify the clinical diagnostic modalities that detect recent/impending thrombosis and, lastly, consider the rational therapeutic approaches recommended for minimising postoperative thrombotic complications.
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Best Pract Res Clin Anaesthesiol · Mar 2010
ReviewPerioperative coagulation management--fresh frozen plasma.
Clinical studies support the use of perioperative fresh frozen plasma (FFP) in patients who are actively bleeding with multiple coagulation factor deficiencies and for the prevention of dilutional coagulopathy in patients with major trauma and/or massive haemorrhage. In these settings, current FFP dosing recommendations may be inadequate. However, a substantial proportion of FFP is transfused in non-bleeding patients with mild elevations in coagulation screening tests. ⋯ FP24 and thawed plasma are alternatives to FFP with similar indications for administration. Both provide an opportunity for increasing the safe plasma donor pool. Although prothrombin complex concentrates and factor VIIa may be used as alternatives to FFP in a variety of specific clinical contexts, additional study is needed.