Perioperative hyperfibrinolysis - physiology and pathophysiology.

INTRODUCTION AND OBJECTIVES: The role of the anesthesiologist in the perioperative management of hemostasis has attracted increasing attention. The fibrinolytic system participates in hemostasis, removing clots after repair of the vascular injury. Over the past two decades, several studies have assessed the efficacy and safety of antifibrinolytic agents in reducing perioperative bleeding and transfusion requirements. Some of the conditions that seem to benefit from antifibrinolytic drugs involve trauma, postpartum hemorrhage, cardiac surgery, spine surgery, knee or hip arthroplasty, urological and gynecological surgery, among others. However, there are currently few publications focusing on the perioperative features of fibrinolytic system, which will be the subject of the present review. CONTENT AND CONCLUSIONS: Fibrinolytic physiology, its relationship with the clot structure and its perioperative behavior are described. Pathophysiological mechanisms related to anesthesiology clinical practice and their possible perioperative scenarios are addressed according to a suggested classification. This article aims to provide anesthesiologists with a broader understanding of the normal functioning of fibrinolysis, the mechanisms of possible deviations from normality in the perioperative period, the pathophysiological rationale supporting the current indications of antifibrinolytics, and some recent outcomes obtained with their use.

Monitoring of coagulation by intraoperative thromboelastometry of liver transplantation in a patient using warfarin - case report / Monitoração da coagulação pela tromboelastometria no intraoperatório de transplante hepático em um paciente usando varfarina - relato de caso

Abstract Introduction: Advanced hepatic disease may - in addition to the widely recognized hemorrhagic complications - occur with thrombotic events. We describe the case of a cirrhotic patient taking warfarin and whose coagulation management during liver transplantation was guided by thromboelastometry (ROTEM®). Case report: A 56 year-old male patient diagnosed with alcohol cirrhosis using warfarin (2.5 mg.day−1) for partial portal vein thrombosis with the International Normalized Ratio (INR) of 2.14. At the beginning of surgery, the ROTEM® parameters were all normal. In the anhepatic phase, EXTEM and INTEM remained normal, but FIBTEM showed reduction of amplitude after 10 min and maximum clot firmness. Finally, in the neohepatic phase, there was a slight alteration in the hypocoagulability of most of the parameters of the EXTEM, INTEM and FIBTEM, besides a notable correction of the Coagulation Time (CT) in HEPTEM compared to the CT of the INTEM. Therefore, the patient did not receive any transfusion of blood products during surgery and in the postoperative period, being discharged on the 8th postoperative day. Discussion: Coagulation deficit resulting from cirrhosis distorts INR as a parameter of anticoagulation adequacy and as a determinant of the need for blood transfusion. Thus, thromboelastometry can provide important information for patient management.

Resumo Introdução: A doença hepática avançada pode, além das complicações hemorrágicas amplamente reconhecidas, ocorrer com eventos trombóticos. Descrevemos o caso de um paciente cirrótico em uso de varfarina, cujo manejo da coagulação durante o transplante de fígado foi guiado por tromboelastometria (ROTEM®). Relato de caso: Paciente do sexo masculino, 56 anos, diagnosticado com cirrose alcoólica, recebendo varfarina (2,5 mg.dia−1) para trombose parcial da veia porta, com razão normalizada internacional (INR) de 2,14. No início da cirurgia, os parâmetros ROTEM® estavam todos normais. Na fase não hepática, EXTEM e INTEM permaneceram normais, mas FIBTEM mostrou redução da amplitude após 10 min e firmeza máxima do coágulo. Por fim, na fase neo-hepática houve uma ligeira alteração da hipocoagulabilidade na maioria dos parâmetros de EXTEM, INTEM e FIBTEM, além de uma correção notável do tempo de coagulação (CT) de HEPTEM em comparação com o CT de INTEM. Portanto, o paciente não recebeu transfusão de hemoderivados durante a cirurgia e no período pós-operatório, obteve alta no oitavo dia de pós-operatório. Discussão: O déficit de coagulação resultante da cirrose distorce o INR como um parâmetro da adequação da anticoagulação e como um determinante da necessidade de transfusão de sangue. Portanto, a tromboelastometria pode fornecer informações importantes para o manejo do paciente.

[Monitoring of coagulation by intraoperative thromboelastometry of liver transplantation in a patient using warfarin - case report]. / Monitoração da coagulação pela tromboelastometria no intraoperatório de transplante hepático em um paciente usando varfarina ­ relato de caso.

INTRODUCTION: Advanced hepatic disease may - in addition to the widely recognized hemorrhagic complications - occur with thrombotic events. We describe the case of a cirrhotic patient taking warfarin and whose coagulation management during liver transplantation was guided by thromboelastometry (ROTEM®). CASE REPORT: A 56 year-old male patient diagnosed with alcohol cirrhosis using warfarin (2.5mg.day-1) for partial portal vein thrombosis with the International Normalized Ratio (INR) of 2.14. At the beginning of surgery, the ROTEM® parameters were all normal. In the anhepatic phase, EXTEM and INTEM remained normal, but FIBTEM showed reduction of amplitude after 10min and maximum clot firmness. Finally, in the neohepatic phase, there was a slight alteration in the hypocoagulability of most of the parameters of the EXTEM, INTEM and FIBTEM, besides a notable correction of the Coagulation Time (CT) in HEPTEM compared to the CT of the INTEM. Therefore, the patient did not receive any transfusion of blood products during surgery and in the postoperative period, being discharged on the 8th postoperative day. DISCUSSION: Coagulation deficit resulting from cirrhosis distorts INR as a parameter of anticoagulation adequacy and as a determinant of the need for blood transfusion. Thus, thromboelastometry can provide important information for patient management.

Perfil transfusional dos cem primeiros pacientes submetidos a transplante hepático em Fortaleza / Transfusion profile of the first one hundred patients undergoing liver transplant in Fortaleza / Perfil de transfusión de los primeros cien pacientes sometidos a trasplante de hígado en Fortaleza

Objetivo: Traçar o perfil transfusional da primeira centena de pacientes submetidos a transplante hepático em um hospital escola, em Fortaleza, Ceará. Método: Trata-se de um estudo observacional, analítico e retrospectivo. Resultados: Dentre os cem pacientes inicialmente incluídos no estudo, houve dez retransplantes. Um paciente foi excluído do estudo por impossibilidade de acesso ao prontuário. Por esses motivos, 89 prontuários foram analisados. Conclusão: Os pacientes, em sua maioria, eram adultos com idade média de 47 anos, do gênero masculino e com grande prevalência de cirurgias abdominais prévias. O grupo sanguíneo mais prevalente foi o grupo A, e a principal causa do transplante, a cirrose por álcool. Em média, os pacientes receberam seis unidades de hemocomponentes, sendo o concentrado de hemácias o mais frequentemente transfundido.

Objective: To identify the profile of the first hundred transfusion patients undergoing liver transplantation at a university hospital in Fortaleza, Ceará. Method: An observational, analytical, and retrospective study was performed. Results: There were 10 retransplantations among the 100 patients initially enrolled in the study. One patient was excluded from the study owing to the inability to access the medical records. For this reason, 89 medical records were analyzed. Conclusion: Most patients were male adults with an average age of 47 years, and a high prevalence of previous abdominal surgeries were observed among them. The most common blood group was group A, and the leading cause of transplantation was cirrhosis induced by alcohol. On average, patients received 6 units of blood components, and the most frequently transfused were packed red blood cells.

Objetivo: Trazar el perfil de transfusión de los cien primeros pacientes sometidos a trasplante de hígado en un hospital universitario en Fortaleza, Ceará, Brasil. Método: Se realizó un estudio de observación, analítico y retrospectivo. Resultados: Entre los 100 pacientes incluidos inicialmente en el estudio, hubo 10 re-trasplantes. Se excluyó un paciente del estudio porque no había acceso a sus registros médicos. Por estas razones, se analizaron 89 registros médicos. Conclusión: La mayoría de los pacientes eran adultos con una edad promedio de 47 años, sexo masculino y con un alto predominio de cirugías abdominales previas. El grupo sanguíneo más frecuente fue el grupo A y la principal causa del trasplante fue la cirrosis inducida por alcohol. En promedio, los pacientes recibieron seis unidades de componentes sanguíneos, siendo el concentrado de glóbulos rojos el más frecuentemente transfundido.

Exames convencionais da coagulação como variáveis preditoras da indicação de transfusão de plasma fresco congelado durante o transplante de fígado

INTRODUÇÃO: sangramento por coagulopatia é problema comum durante o transplante hepático (TH). O uso adequado da monitorização da coagulação pode reduzir a transfusão de hemocomponentes, como o Plasma Fresco Congelado (PFC). Exames Convencionais da Coagulação (ECC), tais como Tempo de Protrombina (TP) e Tempo de Tromboplastina Parcial Ativada (TTPa), são os testes mais amplamente utilizados para monitorizar a coagulação durante o TH, mas algumas limitações têm sido apontadas acerca do seu uso em pacientes cirróticos. OBJETIVO: investigar o uso de ECC como variáveis preditoras da indicação de transfusão de PFC durante o TH em pacientes cirróticos. MÉTODO: analisou-se coorte histórica de 297 transplantes hepáticos com enxertos provenientes de doadores cadáveres. Foram incluídos receptores cirróticos de uma única instituição durante nove anos (2002-2010). A infusão profilática de ácido épsilon-aminocaproico (20 mg/kg/h) e outros pré-requisitos hemostáticos foram mantidos na cirurgia. O TP [expresso na forma de Percentual de Atividade da Protrombina (TP%) e de Relação Normalizada Internacional (INR)] e o TTPa foram medidos no pré-operatório e no fim de cada fase do TH. Os participantes só receberam transfusão de PFC quando se diagnosticou coagulopatia, independentemente dos resultados dos ECC. Os pacientes foram distribuídos em dois grupos, de acordo com a ocorrência de transfusão intraoperatória de PFC. Examinou-se o comportamento dos resultados dos ECC durante a cirurgia. Analisaram-se os fatores de risco para a transfusão de PFC por análises uni e multivariada. Os resultados pós-operatórios de ambos os grupos foram comparados. A acurácia dos ECC para predizer o uso de PFC em cada fase da cirurgia foi investigada por curvas ROC. Além disso, pontos de corte dos ECC não associados à coagulopatia foram calculados para cada fase da cirurgia...

BACKGROUND & AIMS: Bleeding due to coagulopathy is a common problem during liver transplantation (LT). Coagulation monitoring may reduce transfusion of blood components, including Fresh Frozen Plasma (FFP). Conventional coagulation assays (CCA), like Prothrombin Time (PT) and Activated Partial Thromboplastin Time (aPTT), are the most widely employed tests to monitor coagulation during LT, but some limitations have been assigned to their use in cirrhotic patients. This study investigated the predictive value of these blood coagulation tests in predicting FFP transfusions during LT in cirrhotic patients. METHODS: This historical cohort study analyzed 297 isolated, deceased donor LTs performed in cirrhotic patients from a single institution during a nine-year period (2002 - 2010). Prophylactic infusion of epsilon-aminocaproic acid [EACA] (20 mg/kg/h) and other hemostatic requirements were maintained intraoperatively. PT [expressed as Activity Percentage (PT%) and International normalized ratio (INR)] and aPTT [expressed in seconds] were measured preoperatively and by the end of each phase of LT. Hemostatic blood components were transfused only in case of coagulopathy. Patients were divided in two groups according to intraoperative FFP transfusion: FFP group and Non-FFP group. Behavior of CCA results during LT were examined in both groups. Univariate and multivariate analyses of risk factors associated with FFP transfusion were performed. Post-operative outcomes were compared between groups. Accuracy of CCA to predict FFP transfusions was investigated using receiver operating characteristic (ROC) curves. Also, alert values of CCA unassociated with coagulopathy in each phase of surgery were calculated...