Viscoelastic Tests as Point-of-Care Tests in the Assessment and Management of Bleeding and Thrombosis in Liver Disease.

Viscoelastic point-of-care (VET POC) tests provide a global assessment of hemostasis and have an increasing role in the management of bleeding and blood component delivery across several clinical settings. VET POC tests have a rapid turnaround time, provide a better overall picture of hemostasis, predict bleeding more accurately than conventional coagulation tests, and reduce blood component usage and health care costs. Despite commonly having abnormal conventional coagulation tests, most patients with chronic liver disease have a "rebalanced" hemostasis. However, this hemostatic balance is delicate and these patients are predisposed to both bleeding and thromboembolic events. Over recent years, VET POC tests have been increasingly studied for their potential as better functional tests of hemostasis in liver disease patients. This review provides a background on the most common VET POC tests (thromboelastography and rotational thromboelastometry) and discusses the current evidence for these tests in the prediction and management of bleeding and thrombosis in patients with chronic liver disease, and in liver resection and transplant. With the recent publication of several randomized controlled trials, there is growing evidence that VET POC tests may be used to improve bleeding risk assessment and reduce blood product use in liver disease patients outside of the transplant setting. However, consensus is still lacking regarding the VET POC tests' thresholds that should be used to trigger blood product transfusion. VET POC tests also show promise in predicting thrombosis in patients with liver disease, but further research is needed before they can be used to guide anticoagulant therapy.

Energy expenditure early after liver transplantation: Better measured than predicted.

OBJECTIVE: There is no consensus on how to estimate energy requirements after liver transplantation (LT). The aim of this study was to compare measured resting energy expenditure (REE) with predictive equations and fixed factors, and evaluate whether clinical variables were associated with REE. METHODS: During the period of 2011 through 2018, REE measured with indirect calorimetry and predicted by the Harris and Benedict (HB) equation was compared in patients during the first 30 postoperative days after LT. The fixed factors 25 kcal/kg, 30 kcal/kg, or 35 kcal/kg were used to calculate energy requirements. The accuracy of HB and fixed factors were evaluated with a Bland-Altman analysis and Lin's concordance correlation coefficient. The associations of pre- and postoperative clinical variables with REE were evaluated in a multivariate regression analysis. RESULTS: A total of 143 patients were evaluated and had indirect calorimetry performed on postoperative day 6 (interquartile range: 3) in median. The mean measured REE was 1950 ± 461 kcal (range, 720-3309 kcal) or 24.5 ± 6.1 kcal/kg body weight. Large limits of agreements were observed in the Bland-Altman analyses for both HB and fixed factors. HB was closer than fixed factors with a positive concordance (concordance correlation: 0.350; 95% confidence interval, 0.248-0.445) and Pearsons r2 = 0.261. Measured REE was significantly associated (P < 0.05) with age, sex, Model for End-Stage Liver Disease score before LT, surgery time, and graft cold ischemia time according to the multiple regression analysis. CONCLUSIONS: The low accuracy of HB and fixed factors suggests risks of both under- and overfeeding of individual patients if energy requirement is only based on calculation. REE measurement is recommended after LT to secure accurate and safe nutritional therapy.

Assessment of muscle mass depletion in chronic liver disease: Dual-energy x-ray absorptiometry compared with computed tomography.

OBJECTIVES: The aim of this study was to perform intermethod comparisons between the following three measures of muscle mass depletion in patients eligible for liver transplantation: 1) fat-free mass index (FFMI) measured by dual-energy x-ray absorptiometry (DXA), 2) appendicular skeletal muscle mass index (ASMI) measured by DXA, and 3) skeletal muscle index (SMI) measured at the third lumbar level by computed tomography (CT). METHODS: The medical records of patients who received liver transplants between 2009 and 2012 at Karolinska University Hospital were retrospectively reviewed. Adult patients with a chronic liver disease who had both DXA and CT scans performed within a 30-d period during their pretransplant workup were included. RESULTS: Appendicular skeletal muscle mass index measured by DXA (ASMIDXA) and skeletal mass index measured by computed tomography (SMICT) provide similar results when assessing the presence of muscle mass depletion in patients with chronic liver diseases and FFMIDXA can be falsely high in patients with ascites. Both ASMIDXA and SMICT thus appear to be useful methods in the pretransplant evaluation of muscle mass depletion both for patients with and without ascites. CONCLUSIONS: ASMI measured with DXA is a useful alternative method to SMI measured with CT when a CT scan is not clinically indicated or available.

A benefit-risk assessment of dabigatran in the prevention of venous thromboembolism in orthopaedic surgery.

Dabigatran etexilate is a novel orally administered anticoagulant that exerts its action through reversible direct thrombin inhibition. This anticoagulant has been approved for prophylaxis against venous thromboembolism (VTE) after hip or knee arthroplasty, and in a few countries also for atrial fibrillation. This article reviews the efficacy and safety of dabigatran for the prophylaxis of VTE-indication compared with data on the most common current regimen with low-molecular-weight heparin (LMWH), specifically enoxaparin. Alternative prophylactic agents are also discussed. The results regarding efficacy and safety are very similar for dabigatran and LMWH. Bleeding and gastrointestinal reactions are the most frequently reported adverse events with a comparable incidence on LMWH and are probably the result of surgery and anaesthaesia. No adverse event that is specific for dabigatran has been observed in these studies, although dyspepsia has been reported as significantly more frequent than warfarin in long-term studies on other indications. The fact that dabigatran has no antidote has so far not been a problem in patients undergoing orthopaedic surgery. The use of the lower dose of dabigatran (150 mg) appears beneficial to reduce the risk of bleeding in patients over 75 years of age and in those with moderate renal impairment to avoid drug accumulation. The convenience of oral administration is an advantage for dabigatran over LMWH, particularly for extended prophylaxis up to 1 month after surgery. In conclusion, the benefit-risk profile of dabigatran is favourable for use as prophylaxis against VTE after major orthopaedic surgery with its convenient oral administration without need for laboratory monitoring and a low risk of bleeding or other adverse events.