Publications by authors named "Tsai-Wing Ow"

5 Publications

  • Page 1 of 1

Prevalence of bleeding and thrombosis in critically ill patients with chronic liver disease.

Thromb Haemost 2021 Oct 12. Epub 2021 Oct 12.

Institute of Liver Studies, King's College Hospital NHS Foundation Trust, London, United Kingdom of Great Britain and Northern Ireland.

Introduction: Haemorrhage and venous thromboembolism (VTE) are recognised complications of chronic liver disease (CLD), but their prevalence and risk factors in critically ill patients is uncertain.

Patients And Methods: We studied a retrospective cohort of patients with CLD non-electively admitted to a specialist intensive care unit determining the prevalence and timing of major bleeding and VTE (early, present on admission/diagnosed within 48h; later diagnosed >48h post ICU admission). Associations with baseline clinical and laboratory characteristics, multi-organ failure (MOF), blood product administration and mortality were explored. Odds ratios (OR) and 95% CIs were calculated using logistic regression.

Results: Of 623 patients with median age 52, bleeding (>48 hours after admission) occurred in 87 (14%) patients. Bleeding was associated with greater illness severity and increased mortality. Gastrointestinal bleeding accounted for 72% of events, secondary to portal hypertension in >90%. Procedure-related bleeding was uncommon. VTE occurred in 125 (20%) patients: Early VTE in 80 (13%) and involving the portal vein (PVT) in 85%. Later VTE affected 45 (7.2%) patients. Hepatocellular Carcinoma (HCC) and non-alcoholic liver disease were independently associated with early VTE (OR 2.79, (95% CI 1.5 -5.2) and 2.32, (1.4 -3.9) respectively), and HCC, sepsis and cryoprecipitate use with late VTE (OR 2.45, (1.11-5.43), 2.26 (1.2-4.3) and 2.60 (1.3-5.1).

Conclusion: VTE was prevalent on admission to critical care and less commonly developed later. Bleeding was associated with MOF and increased mortality. Severe MOF was not associated with an increased rate of VTE which was linked with HCC, and specific etiologies of CLD.
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October 2021

Efficacy of pro- and anticoagulant strategies in plasma of patients undergoing hepatobiliary surgery.

J Thromb Haemost 2020 11 10;18(11):2840-2851. Epub 2020 Sep 10.

Surgical Research Laboratory and Section of Hepatobiliary Surgery and Liver transplantation, Department of Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.

Background: In vitro efficacy of pro- and antihemostatic drugs is profoundly different in patients with compensated cirrhosis and in those who have cirrhosis and are critically ill.

Objectives: Here we assessed the efficacy of pro- and anticoagulant drugs in plasma of patients undergoing hepato-pancreato-biliary (HPB) surgery, which is associated with unique hemostatic changes.

Methods: We performed in vitro analyses on blood samples of 60 patients undergoing HPB surgery and liver transplantation: 20 orthotopic liver transplantations, 20 partial hepatectomies, and 20 pylorus-preserving pancreaticoduodenectomies. We performed thrombin generation experiments before and after in vitro addition of fresh frozen plasma (FFP), prothrombin complex concentrate (PCC), recombinant factor VIIa (rFVIIa), low molecular weight heparin (LMWH), unfractionated heparin, dabigatran, and rivaroxaban.

Results: We showed that patients undergoing HPB surgery are in a hypercoagulable state by thrombin generation testing. FFP and rFVIIa had minimal effects on thrombin generation, whereas PCC had a more pronounced procoagulant effect in patients compared with controls. Dabigatran showed a more pronounced anticoagulant effect in patients compared with controls, whereas rivaroxaban and LMWH had a decreased anticoagulant effect in patients.

Conclusion: We demonstrate profoundly altered in vitro efficacy of commonly used anticoagulants, in patients undergoing HPB surgery compared with healthy controls, which may have implications for anticoagulant dosing in the early postoperative period. In the correction of perioperative bleeding complications, PCCs appear much more potent than FFP or rFVIIa, and PCCs may require conservative dosing and caution in use in patients undergoing HPB surgery.
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November 2020

Whole blood thrombin generation profiles of patients with cirrhosis explored with a near patient assay.

J Thromb Haemost 2020 04 18;18(4):834-843. Epub 2020 Feb 18.

Institute of Liver Studies, King's College Hospital, London, UK.

Background And Aims: Patients with cirrhosis have a rebalanced hemostasis, often with normal or elevated thrombin-generating (TG) capacity in plasma. Whole blood (WB) TG allows faster determination and, importantly, includes the influence of all circulating blood cells. We aimed to study the TG profile of patients with cirrhosis in WB and in platelet poor plasma.

Methods: Thrombin-generating capacity in WB and plasma were assessed with a near-patient WB-TG assay and the calibrated automated thrombinography assay, respectively. TG assays were tested in presence and absence of thrombomodulin. Conventional coagulation tests were also performed.

Results: Thirty-four patients with cirrhosis and twenty-two controls were analyzed. Compared with controls, patients had substantially deranged results in conventional coagulation tests. Comparable WB-TG capacity (endogenous thrombin potential until peak, ETPp) but significantly lower peak thrombin were found in patients, and these results persisted when thrombomodulin was present. TG of the patients was more resistant to thrombomodulin than controls in both WB and plasma, although the inhibitory effect of thrombomodulin was drastically weaker in WB than in plasma. The peak of WB-TG in patients correlated moderately with their hematocrit and platelet count. Significant correlations were found between TG results in WB and plasma.

Conclusions: The WB-TG assay shows a normal to hypocoagulable state in patients with cirrhosis with a decreased anticoagulant activity of TM compared to plasma-TG. The clinical value of this assay needs further validation.
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April 2020

Saving costs through a coordinated care model for patients with hepatocellular cancer.

Intern Med J 2017 Sep;47(9):1005-1011

Department of Gastroenterology and Hepatology, Royal Adelaide Hospital, Adelaide, South Australia, Australia.

Background: In keeping with recent trends, patients with hepatocellular cancer have had their care managed by a dedicated Nurse Coordinator at our tertiary Australian hospital since 2010. To date, there are few data to justify the cost-effectiveness of this approach.

Aims: To quantify the potential cost saved through the employment of a Nurse Coordinator in the management of patients with hepatocellular carcinoma at a single tertiary-level Australian hospital.

Methods: A retrospective audit of patients managed by the Nurse Coordinator between 2010 and 2015 was conducted. Consensus reports from previous meetings were reviewed, and nurse-initiated radiological procedures and encounters were identified. Clinical activities were prospectively evaluated over a 1-month period in July-August 2015. The equivalent annual number of outpatient medical encounters spared was calculated. Using the national average cost of each gastroenterology outpatient encounter, a total annual cost was determined and was compared against the cost of funding the position.

Results: The activity of the Nurse Coordinator resulted in an equivalent of at least 175 outpatient encounters being spared per year, with a minimum annual cost saving of $85 750. A total of 113 encounters resulted from the independent delivery and initiation of multidisciplinary team meeting plans; 10 were attributed to nurse-led patient education, and 52 were equated to weekly clinical activities. This represented a net annual saving of $17 050.

Conclusion: The incorporation of the Nurse Coordinator in the care pathway of patients with hepatocellular cancer is associated with a reduction in medical outpatient load and, consequently, a significant annual cost saving.
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September 2017

Ultrathin disposable gastroscope for screening and surveillance of gastroesophageal varices in patients with liver cirrhosis: a prospective comparative study.

Gastrointest Endosc 2017 Jun 25;85(6):1212-1217. Epub 2016 Nov 25.

Department of Gastroenterology and Hepatology, Royal Adelaide Hospital, Adelaide, South Australia, Australia; Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia.

Background And Aims: This study aims to evaluate the role of unsedated, ultrathin disposable gastroscopy (TDG) against conventional gastroscopy (CG) in the screening and surveillance of gastroesophageal varices (GEVs) in patients with liver cirrhosis.

Method: Forty-eight patients (56.4 ± 1.3 years; 38 male, 10 female) with liver cirrhosis referred for screening (n = 12) or surveillance (n = 36) of GEVs were prospectively enrolled. Unsedated gastroscopy was initially performed with TDG, followed by CG with conscious sedation. The 2 gastroscopies were performed by different endoscopists blinded to the results of the previous examination. Video recordings of both gastroscopies were validated by an independent investigator in a random, blinded fashion. Endpoints were accuracy and interobserver agreement of detecting GEVs, safety, and potential cost saving.

Results: CG identified GEVs in 26 (54%) patients, 10 of whom (21%) had high-risk esophageal varices (HREV). Compared with CG, TDG had an accuracy of 92% for the detection of all GEVs, which increased to 100% for high-risk GEVs. The interobserver agreement for detecting all GEVs on TDG was 88% (κ = 0.74). This increased to 94% (κ = 0.82) for high-risk GEVs. There were no serious adverse events.

Conclusions: Unsedated TDG is safe and has high diagnostic accuracy and interobserver reliability for the detection of GEVs. The use of clinic-based TDG would allow immediate determination of a follow-up plan, making it attractive for variceal screening and surveillance programs. (Clinical trial (ANZCTR) registration number: ACTRN12616001103459.).
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June 2017