Coagulation point-of-care testing on the labour ward should be mandatory

SHock-INduced Endotheliopathy (SHINE): A mechanistic justification for viscoelastography-guided resuscitation of traumatic and non-traumatic shock

Irrespective of the reason for hypoperfusion, hypocoagulable and/or hyperfibrinolytic hemostatic aberrancies afflict up to one-quarter of critically ill patients in shock. Intensivists and traumatologists have embraced the concept of SHock-INduced Endotheliopathy (SHINE) as a foundational derangement in progressive shock wherein sympatho-adrenal activation may cause systemic endothelial injury. The pro-thrombotic endothelium lends to micro-thrombosis, enacting a cycle of worsening perfusion and increasing catecholamines, endothelial injury, de-endothelialization, and multiple organ failure. The hypocoagulable/hyperfibrinolytic hemostatic phenotype is thought to be driven by endothelial release of anti-thrombogenic mediators to the bloodstream and perivascular sympathetic nerve release of tissue plasminogen activator directly into the microvasculature. In the shock state, this hemostatic phenotype may be a counterbalancing, yet maladaptive, attempt to restore blood flow against a systemically pro-thrombotic endothelium and increased blood viscosity. We therefore review endothelial physiology with emphasis on glycocalyx function, unique biomarkers, and coagulofibrinolytic mediators, setting the stage for understanding the pathophysiology and hemostatic phenotypes of SHINE in various etiologies of shock. We propose that the hyperfibrinolytic phenotype is exemplified in progressive shock whether related to trauma-induced coagulopathy, sepsis-induced coagulopathy, or post-cardiac arrest syndrome-associated coagulopathy. Regardless of the initial insult, SHINE appears to be a catecholamine-driven entity which early in the disease course may manifest as hyper- or hypocoagulopathic and hyper- or hypofibrinolytic hemostatic imbalance. Moreover, these hemostatic derangements may rapidly evolve along the thrombohemorrhagic spectrum depending on the etiology, timing, and methods of resuscitation. Given the intricate hemochemical makeup and changes during these shock states, macroscopic whole blood tests of coagulative kinetics and clot strength serve as clinically useful and simple means for hemostasis phenotyping. We suggest that viscoelastic hemostatic assays such as thromboelastography (TEG) and rotational thromboelastometry (ROTEM) are currently the most applicable clinical tools for assaying global hemostatic function-including fibrinolysis-to enable dynamic resuscitation with blood products and hemostatic adjuncts for those patients with thrombotic and/or hemorrhagic complications in shock states.

Point-of-care coagulation testing for postpartum haemorrhage

The use of viscoelastic haemostatic assays (VHAs) to guide blood product replacement during postpartum haemorrhage is expanding. Rotem and TEG devices can be used to detect and treat clinically significant hypofibrinogenaemia, although evidence to support the role of VHAs for guiding fresh frozen plasma and platelet transfusion is less clear. If Rotem/TEG traces are normal, clinicians should investigate for another cause of bleeding, and haemostatic support is not required. Guidelines support the use of VHAs during postpartum haemorrhage as part of locally agreed algorithms. There is a wide consensus that fibrinogen replacement is needed if the Fibtem A5 is <12 mm and if there is ongoing bleeding. Guidelines recommend against using VHAs to guide tranexamic acid infusion, and this drug should be given as soon as bleeding is recognised, irrespective of the Rotem/TEG traces. The cost-effectiveness of VHAs during postpartum haemorrhage needs to be addressed.

Point-of-Care Viscoelastic Tests in the Management of Obstetric Hemorrhage

Obstetric hemorrhage remains the leading cause of maternal morbidity and mortality worldwide. Thromboelastography and rotational thromboelastometry are laboratory methods of assessing the kinetics of blood clot formation through real-time measurement of viscoelastic clot strength and may aid in management of severe hemorrhage. Although first described more than 70 years ago, viscoelastic testing devices are now available that allow for rapid point-of-care use of this technology to aid in real-time management of blood product replacement in cases of severe hemorrhage. These devices can be used to visually estimate multiple facets of hemostasis-coagulation, platelet function, and fibrinolysis-within 10-20 minutes. They have been used successfully in cardiac surgery, trauma, and liver transplantation and have potential for use in management of obstetric hemorrhage. Goals with their use include targeted transfusion of blood and its components for specific coagulation deficiencies. To date, however, published experiences with the use of these viscoelastic tests for obstetric hemorrhage have been limited. Because of the increasing use of the point-of-care tests by anesthesiologists, surgeons, and intensivists, the purpose of this report is to familiarize obstetricians with the technology involved and its use in severe hemorrhage complicating pregnancy.

Patient blood management in India - Review of current practices and feasibility of applying appropriate standard of care guidelines. A position paper by an interdisciplinary expert group

In a developing country like India, with limited resources and access to healthcare facilities, dealing with massive hemorrhage is a major challenge. This challenge gets compounded by pre-existing anemia, hemostatic disorders, and logistic issues of timely transfer of such patients from peripheral hospitals to centers with adequate resources and management expertise. Despite the awareness amongst healthcare providers regarding management modalities of bleeding patients, no uniform Patient Blood Management (PBM) or perioperative bleeding management protocols have been implemented in India, yet. In light of this, an interdisciplinary expert group came together, comprising of experts working in transfusion medicine, hematology, obstetrics, anesthesiology and intensive care, to review current practices in management of bleeding in Indian healthcare institutions and evaluating the feasibility of implementing uniform PBM guidelines. The specific intent was to perform a gap analysis between the ideal and the current status in terms of practices and resources. The expert group identified interdisciplinary education in PBM and bleeding management, bleeding history, viscoelastic and platelet function testing, and the implementation of validated, setting-specific bleeding management protocols (algorithms) as important tools in PBM and perioperative bleeding management. Here, trauma, major surgery, postpartum hemorrhage, cardiac and liver surgery are the most common clinical settings associated with massive blood loss. Accordingly, PBM should be implemented as a multidisciplinary and practically applicable concept in India in a timely manner in order to optimize the use the precious resource blood and to increase patients' safety.

Assessment of the reliability and validity of a novel point-of-care fibrinogen (F-Point) device against an industry standard at fibrinogen levels >2 g/L in non-haemorrhage scenarios

INTRODUCTION

A diagnostic accuracy study assessing the reliability and validity of a novel plasma fibrinogen point-of-care (F-Point) device compared with the von Clauss method of assay.

METHODS

Forty-one women presenting for elective caesarean delivery and 43 non-pregnant female patients presenting for elective gynaecological surgery were recruited to assess agreement at normal fibrinogen levels (elective gynaecological cohort) and high fibrinogen levels (elective caesarean section cohort). Validity was assessed by comparing the F-Point results with the gold standard of von Clauss fibrinogen assay performed on the ACL Top 500. Reliability (test-retest) and validity were assessed using the intraclass correlation to control for operator variance (two-way random absolute agreement method), presented as intra class correlation coefficients (ICCs) and 95% confidence interval, and Bland-Altman analysis, presented as mean bias and 95% limits of agreement and coefficient of variation (COV).

RESULTS

The results demonstrated a high test-retest reliability demonstrated in the paired F-Point measurements with an intraclass correlation coefficient (ICC) of 0.95, a bias of 0 (-00.69 to 0.69) and a COV of 9%. Similarly, there was acceptable agreement demonstrated between F-Point and von Clauss assay with an ICC of 0.91, a bias of -0.1 (-0.96 to 0.75) and a COV of 11%.

CONCLUSIONS

Our novel plasma fibrinogen point-of-care device has been shown to be reliable and valid when testing fibrinogen levels as low as 2 g/L. Future studies investigating the correlation at lower fibrinogen levels, for example during haemorrhage and in patients with coagulopathies, are required.

The role of evidence-based algorithms for rotational thromboelastometry-guided bleeding management

Rotational thromboelastometry (ROTEM) is a point-of-care viscoelastic method and enables to assess viscoelastic profiles of whole blood in various clinical settings. ROTEM-guided bleeding management has become an essential part of patient blood management (PBM) which is an important concept in improving patient safety. Here, ROTEM testing and hemostatic interventions should be linked by evidence-based, setting-specific algorithms adapted to the specific patient population of the hospitals and the local availability of hemostatic interventions. Accordingly, ROTEM-guided algorithms implement the concept of personalized or precision medicine in perioperative bleeding management (‘theranostic’ approach). ROTEM-guided PBM has been shown to be effective in reducing bleeding, transfusion requirements, complication rates, and health care costs. Accordingly, several randomized-controlled trials, meta-analyses, and health technology assessments provided evidence that using ROTEM-guided algorithms in bleeding patients resulted in improved patient’s safety and outcomes including perioperative morbidity and mortality. However, the implementation of ROTEM in the PBM concept requires adequate technical and interpretation training, education and logistics, as well as interdisciplinary communication and collaboration.