The INR is only one side of the coagulation cascade: time to watch the clot

Comparison between thromboelastography and conventional coagulation assays in patients with deep vein thrombosis

BACKGROUND

Conventional coagulation assays (CCAs) are of limited value in the assessment of coagulation status in patients with deep vein thrombosis (DVT). We aimed to compare thromboelastography (TEG) and CCAs in identifying DVT and evaluating coagulation status in DVT patients.

METHODS

Sixty-six patients diagnosed with DVT and forty healthy controls were enrolled. Blood samples were collected within 4 h of patients' admission to hospital before any operation and tested by TEG and CCAs. TEG and CCA parameters were compared between DVT patients and controls. The ability of each parameter in identifying DVT was assessed. Pearson's correlation was used to determine the correlation between TEG and CCA parameters among the study population.

RESULTS

TEG showed significant differences between DVT patients and controls, indicating a hypercoagulable tendency in patients suffering from DVT. In contrast, no significant difference regarding CCAs was observed between the DVT and control group. Furthermore, TEG displayed a better capacity in identifying DVT than CCAs. In addition, Pearson's correlation analysis showed TEG and CCA parameters had few correlations.

CONCLUSION

TEG has advantages in identifying DVT and detecting hypercoagulability, and provides a better insight in evaluating coagulation status in patients with DVT than CCAs.

Thoracic Epidural Analgesia for Postoperative Pain Management in Liver Transplantation: A 10-year Study on 685 Liver Transplant Recipients

Thoracic epidural analgesia (TEA) is not widely used for postoperative pain management in liver transplantation due to hepatic coagulopathy-related increased risk of inducing an epidural hematoma. However, an increasing number of patients are transplanted for other indications than the end-stage liver disease and without coagulopathy allowing insertion of an epidural catheter.

Coagulation in liver surgery: an observational haemostatic profile and thromboelastography study

BACKGROUND

International normalized ratio (INR) is used as a marker of the haemostatic status following liver resection. However, the impact of liver resection on haemostasis is complex and beyond what can be measured by INR. This study aimed to prospectively assess haemostatic profile following liver resection and determine if INR measurement can safely guide post-operative thromboprophylaxis.

METHODS

In this prospective cohort study, patients undergoing liver resection had coagulation parameters (International normalised ratio (INR), prothrombin time (PT), activated partial thromboplastin time, fibrinogen, d-dimer, von Willebrand factor antigen, procoagulant activity of phospholipids and clotting factors II, VII, VIIIc, IX and X) and thromboelastogram parameters assessed perioperatively. Clinical follow-up assessed for thromboembolism and haemorrhage.

RESULTS

In the 41 patients included, INR was significantly (P < 0.0001) elevated post-operatively, and INR >1.5 was observed in seven of 41 (17.1%) on post-operative day 1 and one of 41 (2.4%) patients on post-operative day 3, respectively. Factor VII levels showed transient reduction but other factors, especially factors II and X, remained within normal range following liver resection. Thromboelastogram parameters remained normal or supranormal for all patients at all time points. One incident of post-hepatectomy haemorrhage occurred, despite a normal coagulation profile. Two patients suffered late pulmonary embolic episodes.

CONCLUSION

Post liver resection haemostasis is complex and poorly reflected by INR, which should not guide initiation of chemical thromboprophylaxis in the immediate post-operative period.

Closing the gap - detection of clinically relevant von Willebrand disease in emergency settings through an improved algorithm based on rotational Thromboelastometry

Background

Hemorrhage and blood loss are still among the main causes of preventable death. Global hemostatic assays are useful point-of-care test (POCT) devices to rapidly detect cumulative effects of plasma factors and platelets on coagulation. Thromboelastography (TEG) and Thromboelastometry (ROTEM) are established methods in many anesthesiological departments for guided hemostatic treatment. However, von Willebrand disease remains undetected by standard ROTEM, especially during emergency care, despite being the most prevalent congenital hemostatic disorder.

Methods

In our monocentric cohort pilot study we focused on hemostatic challenges associated with von Willebrand disease. Twenty-seven patients with suspected von Willebrand disease were included. We modified the routine ROTEM assay by adding a preincubation with ristocetin and commercially available plasma-derived von Willebrand factor to identify clinically relevant von Willebrand disease (VWD).

Results

Addition of von Willebrand factor to the ristocetin assay of a VWD type 3 patient restored the reaction of the whole blood probe to match the response of a healthy person. Our modified ROTEM assay with ristocetin (Ricotem) showed that all high responders (n = 7) had VWD. In the low responder group (n = 16) – 10 of 16 had VWD and in the normal responder group (n = 5), 2 of 5 had mild type 1 VWD.

Conclusions

This new modification of the standard ROTEM assay enables the detection of otherwise unnoticed critical von Willebrand disease based on alterations in clot formation and might serve as a novel approach to reliably assess severe VWD patients by platelet-mediated blood clotting in an emergency setting. We recommend incorporating this new VWD-focused screening tool into the current ROTEM-based management algorithm of acute microvascular bleeding.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0672-8) contains supplementary material, which is available to authorized users.

Incidence and Risk Factors of Intracranial Hemorrhage in Liver Transplant Recipients

BACKGROUND

Intracranial hemorrhage after liver transplantation is an infrequently reported complication but one which can have devastating consequences.

METHODS

We performed a retrospective cross-sectional analysis of all liver transplants performed between January 2010 and June 2015 at a single high-volume institution using a prospectively maintained electronic database and query of the electronic medical record. Cases of intracranial hemorrhage were adjudicated as either spontaneous intraparenchymal hemorrhage(IPH) or extra-axial hemorrhage (EAH). Patients with confirmed intracranial hemorrhage were compared with all other liver transplant recipients. Risk factors were identified by univariate analysis and logistic regression models for IPH and EAH.

RESULTS

Thirty-one (5.2%) of 595 liver transplant recipients developed an intracranial hemorrhage within 12 months of transplantation, 15 IPH and 16 EAH. The majority of intracranial hemorrhages were diagnosed within 1 month of transplantation. Eight (26%) intracranial hemorrhage patients died during hospitalization. Fourteen (45%) intracranial hemorrhage patients died within 1 year of transplantation and 1-year mortality was greater than in patients without intracranial hemorrhage (11.2%, P < 0.01). Female sex (adjusted odds ratio [OR], 3.291; 95% confidence interval [CI], 1.092-9.924; P = 0.034), higher pretransplant bilirubin (adjusted OR, 1.037; 95% CI, 1.006-1.070; P = 0.020), and greater increase in pretransplant to posttransplant systolic blood pressure (adjusted OR, 1.029; 95% CI, 1.006-1.052; P = 0.012) were associated with posttransplant IPH. Lower pretransplant serum fibrinogen level (adjusted OR, 0.988; 95% CI, 0.979-0.998; P = 0.017) was associated with posttransplant EAH.

CONCLUSIONS

Postoperative blood pressure control and pretransplant fibrinogen levels may be modifiable risk factors for preventing posttransplant intracranial hemorrhage.