Bedside Coagulometry During Intravenous Heparin Therapy after Coronary Angioplasty

In order to assess the applicability of a bedside coagulometer for measurement of b-APTT, serial blood samples were obtained from 20 patients receiving intravenous heparin treatment following PTCA, and from 5 healthy volunteers. B-APTT was analysed bedside on the Hemochron® coagulometer; p-APTT and p-heparin, measured asfactor anti-Xa activity, were analysed ex-vivo in the laboratory. B-APTT values, determined by the Hemochron coagulometer, were closely correlated to p-heparin (r=0.83, p<0.001, SD=52 seconds (sec), n=89), and duplicate determinations of b-APTT on the Hemochron coagulometer showed an acceptable repeatability. However, an APTT ratio of 1.5–2.5 was not related to a therapeutic p-heparin level, neither as measured by the Hemochron device nor in the laboratory. Abstract. Background: When administering intravenous heparin during angioplasty procedures, a quick and reliable method for safe and effective monitoring of anticoagulation is necessary. Objective: To assess the applicability of a bedside coagulometer, measuring the activated partial thromboplastin time (APTT) in patients receiving intravenous heparin treatment after percutaneous transluminal coronary angioplasty (PTCA). Methods: In patients with stable angina pectoris, receiving intravenous heparin treatment following PTCA, serial blood samples were obtained by venipuncture and from the arterial sheath for analysis of whole blood APTT (b-APTT), and plasma heparin concentration (p-heparin). Additionally, in healthy volunteers blood samples were obtained after a single bolus injection of heparin. B-APTT was analysed bedside on the Hemochron® coagulometer; p-APTT and p-heparin, measured as factor anti-Xa activity, were analysed ex-vivo in the laboratory using conventional analytical methods. Results: In 20 patients a total of 94 venous and 69 arterial blood samples were analysed, and in five healthy volunteers analyses were performed in 20 venous blood samples. B-APTT values, determined by the Hemochron coagulometer, were closely correlated to p-heparin (r=0.83, p<0.001, SD=52 seconds (sec), n=89). An APTT ratio of 1.5–2.5 was not related to a therapeutic p-heparin level, however, neither when using APTT assessed by the Hemochron device nor APTT measured in the laboratory. Duplicate determinations of b-APTT on the Hemochron coagulometer showed an acceptable repeatability; the mean difference between duplicate measurements was 4[emsp4 ] sec (coefficient of variation (c.v.)=6%, p<0.05, n=163). Conclusions: In patients receiving intravenous heparin after PTCA treatment, b-APTT values measured by the Hemochron method showed an acceptable repeatability and were significantly correlated to p-heparin.     

Anticoagulation

The increasing incidence of thrombosis in hospitalized patients in the 21st century is due to improved awareness by clinicians and more sophisticated forms of imaging. Thromboprophylaxis is now an imperative in the NHS of the UK and this combined with new, improved and safer forms of anticoagulation means that postoperative deaths from venous thromboembolic disease should become a thing of the past. In the following paper the authors review the up-to-date literature with emphasis on the newer anticoagulants that do not require blood test monitoring. We fully accept that this is a developing field and that the recognized indications for certain of these agents will change with the accumulation of further evidence.     

Clinical Safety and Anticoagulation Efficacy of Low-Molecular-Weight Heparins in Chronic Hemodialysis Patients: A Single Medical Center Experience

Background: In many countries low-molecular-weight heparins (LMWHs) are increasingly used for hemodialysis (HD). Low-range activated clotting time (ACT-LR) values and anti-Xa activity had been used to monitor the degree of anticoagulation caused by LMWH. However, the facilities are not easily available at most hospitals. Such data are limited in Taiwan. Methods: A total of 76 patients receiving maintenance HD were prospectively enrolled. The HD patients were randomized to receive either nadroparin or enoxaparin and checked the ACT-LR values and anti-Xa activity. We aimed to analyze ACT-LR values and anti-Xa activity along with the clotting of the dialyzer or bleeding events associated with two LMWHs after they were administered. We also aimed to determine the dose necessary to reach maximum safety and efficacy. Results: We found no significant differences in LMWH dosage, ACT-LR values, and anti-Xa activity between the two groups. There were no significant differences in bleeding/adverse events and extracorporeal circuit thrombosis between the two groups. Most of the bleeding and adverse events were subcutaneous minor bleeding. No major bleeding or mortality was found. We found significant differences in mean dosage, cost, bleeding/adverse effect, and extracorporeal circuit thrombosis between excessive and reduced nadroparin dosage groups. Conclusion: LMWH is not still routinely used due to its high cost in Taiwan. In our clinical experience, nadroparin and enoxaparin exhibited high levels of safety and efficacy in chronic HD patients. Reduced LMWHs dosage could promote patient’s safety and decreased HD cost in HD patients with excessive dosage of LMWHs.     

Cancer risk is not increased after conventional hip arthroplasty

Background and purpose Wear debris from conventional total hip arthroplasty (THA) induces chromosomal aberrations and DNA damage, which may promote cancerogenesis. A long latent period is required for solid tumors. We therefore re-analyzed a large THA cohort for cancer.

Patients and methods We updated a cohort of 24,636 patients with primary osteoarthritis and metal-on-polyethylene THA who had been entered in the Finnish Arthroplasty Register between 1980 and 1995, and linked it to the Finnish Cancer Registry for cancer risk assessment up to 2005. The mean follow-up time was 13 years. The numbers of cancer cases observed were compared with expected rates based on incidence in the general population.

Results The standardized incidence ratio (SIR) for the whole follow-up period was 0.95 (95% confidence interval (CI): 0.92–0.97). After 10 years of follow-up, the SIR was equal to that in the normal population (SIR = 0.98, 95% CI: 0.94–1.03). Incidence of lung cancer was low throughout the follow-up time and that of prostate cancer was slightly elevated. The incidence rates for all other forms of cancer did not deviate significantly from those in the normal population.

Interpretation We found no increased cancer risk in patients with conventional THA after an average of 13 years and up to 25 years of follow-up.     

The effect of collagen,Interleukin-l α and glicosaminoglycan on the neovascularization of central nervous system

Abstract

Neovascularization, the development of a new microvasculature, has an important role in physiological and pathological processes. The vascular changes in the brain can be easily detected because the proliferation of endothelial cells in its vascular structure is quite small, and so constitutes a good model for neovascularization studies. In the present investigation, to induce intracerebral neovascularization, we implanted collagen, Interleukin-l alpha (IL-lα) and glicosaminoglycan into the brain ofpigs, in order to test the hypothesis that IL-l α, collagen and glicosaminoglycan play a pivotal. role in the process of neovascularization. Both pure collagen and collagen combined with IL-l a induced neovascularization according to light-electron microscopic findings and values of enzymes' activities. In particular, collagen combined with IL-lα synergically affected the increase of neovascularization. However, glicosarrinoglycan did not affect it significantly. Although the results of this study provided us with some interesting data indicating the beneficial effects of collagen combined with IL-1α on neovascularization, further studies should be done to study the short term effect of these biochemical substances. [Neural Res 1998; 20: 513-525]     

What Impact Does Venous Thromboembolism and Bleeding Have on Cancer Patients’ Quality of Life?

Background

Venous thromboembolism (VTE) is common in cancer patients and its treatment is associated with a high risk of recurrent VTE (rVTE) and bleeding.

Low molecular weight heparin versus unfractioned heparin for anticoagulation during perioperative extracorporeal membrane oxygenation: A single center experience in 102 lung transplant patients

Extracorporeal membrane oxygenation (ECMO) is gaining importance in the perioperative management of lung transplant patients. To date, the ideal substance for anticoagulation of ECMO patients is still a matter of debate. In this study, we describe our experience with the use of low molecular weight heparin (LMWH) in comparison with unfractioned heparin (UFH) in lung transplant patients undergoing perioperative ECMO support. We retrospectively analyzed data from all lung transplant patients who underwent perioperative ECMO support at our institution between 2013 and 2017. Bleeding events served as primary outcome parameter. Secondary outcome parameters consisted of thromboembolic events. 102 patients were included in this study, of which 22 (21.6%) received UFH for anticoagulation, and 80 (78.4%) received LMWH. There was no difference between the two groups in regard to serious bleeding events (22.7% in the UFH group vs 12.5% in the LMWH group, P = .31). However, the proportion of patients experiencing thromboembolic events was significantly higher in the UFH group than in the LMWH group (50% vs 20%, P = .01). After adjusting for baseline differences between the two groups, we still observed a difference with respect to thromboembolic events. These data remain to be validated in future prospective, randomized trials.