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Background: Although the use of thromboprophylaxis is well established, there is no consensus on the preferred thromboprophylaxis regimen after THA; large, population-based studies offer an opportunity to examine this problem in a robust way that can complement results from randomized trials.Questions/purposes: Using data from a large national registry, we asked: (1) Is there any difference between low-molecular weight heparin (LMWH) and new oral anticoagulants in preventing symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE), after THA? (2) Are there any differences in safety parameters, such as bleeding, reoperations and mortality, between LMWH and new oral anticoagulants?Methods: Between 2008 and 2012, 78,066 THAs were performed in Sweden. This study evaluated 32,663 (42%) of them, selected through the merger of several national registries. These patients underwent unilateral THA due to primary osteoarthritis. They had not experienced any venous thromboembolic events 5 years before the index operation and were not prescribed potent antithrombotic agents, of any type, in the 6 months before the index operation. Additionally, their postoperative thromboprophylaxis was confirmed in a national registry by purchase of prescribed medications. We divided the cohort into two groups: those patients who received new oral anticoagulants (5752, 18%) and those who received LMWH (26,881, 82%) as postoperative thromboprophylaxis. Our primary endpoints were the frequencies of symptomatic DVT and symptomatic PE within 3 months of surgery. Our secondary comparison was a between-group comparison of bleeding (by way of diagnostic coding), reoperation, and mortality within 3 months of surgery. Odds ratios (OR) are presented with 95% confidence intervals (CIs) as pooled results for the two groups after adjustment for duration of thromboprophylaxis (short or extended for at least 28 days), year of the index operation, Elixhauser comorbidity index, sex, age and previous treatment with platelet aggregation inhibitors.Results: The risk of symptomatic DVT was lower in the group that received new oral anticoagulants than the group that received LMWH (0.3% versus 0.6%, OR, 0.47; 95% CI, 0.27-0.76; p = 0.026). The risk of symptomatic PE was lower in the group that received new oral anticoagulants than the group that received LMWH (0.1% versus 0.4%, OR, 0.36; 95% CI, 0.16-0.69; p = 0.005). There was no difference in the risk of bleeding (by way of diagnostic coding) (OR, 1.03; 95% CI, 0.82-1.28; p = 0.688), reoperation (OR, 1.02; 95% CI, 0.71-1.44; p = 0.860) or mortality (OR, 0.83; 95% CI, 0.31-1.88; p = 0.883) between groups.Conclusions: New oral anticoagulants were associated with a lower risk of symptomatic DVT and symptomatic PE in this large, registry study, and we observed no differences in the risk of bleeding, reoperation, or death between the groups. Although we were able to control for a number of potential confounding variables, we cannot ascertain the indications that drove the prescription decisions in this setting, and there were important between-group differences in terms of duration of thromboprophylaxis (new oral anticoagulants generally were used for a longer period of time after surgery). Future studies, preferably large randomized trials with pragmatic inclusion criteria, to analyze symptomatic DVT, symptomatic PE and death are needed to confirm or refute our findings.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background In adults with moderate renal impairment (creatinine clearance [CrCl] 30–50 mL/min) undergoing total hip or knee replacement (THR/TKR), the recommended dose of dabigatran etexilate is 150 mg once daily (qd). We investigated the steady state pharmacokinetics, pharmacodynamics and safety in these patients. Methods Single-arm, open-label phase 4 study ( NCT01184989 ) in Caucasian patients receiving dabigatran etexilate 75 mg 1–4 h after surgery and 150 mg qd on days 2–10 (TKR) or days 2–35 (THR). Plasma total dabigatran concentrations (day 6 ± 1) were determined by high-performance liquid chromatography tandem mass spectrometry and indirectly using the commercially available diluted thrombin time (dTT) assay (Hemoclot® Thrombin Inhibitors). Results Of 112 patients (mean CrCl 42.5 mL/min, age 79.1 years, 69.6% female), 100 completed the study. Geometric mean trough and peak dabigatran concentrations were 47.5 ng/mL (10th–90th percentile 19.7–120) and 166 ng/mL (49.1–364), respectively. There were four major bleeding events and no venous thromboembolic events. Dabigatran concentrations determined from dTT (and falling within the assay range of 50–500 ng/mL) underestimated actual values by 7.6% (90% confidence interval 5.3, 9.9), which is within the acceptance limits of ± 15%. Conclusions These findings in Caucasians with moderate renal impairment undergoing THR or TKR support the use of the 150 mg qd dose of dabigatran etexilate. With adequate set-up, calibration and quality control the dTT assay might be appropriate for situations, such as serious bleeding or a need for urgent surgery, where determination of dabigatran levels would be helpful. [ABSTRACT FROM AUTHOR]

Background: Two phase 3 trials compared 28-35 days of treatment with oral dabigatran 220 mg or 150 mg (RE-NOVATE) or 220 mg (RE-NOVATE II) once daily with subcutaneous enoxaparin 40 mg once daily for prevention of venous thromboembolism (VTE) after elective total hip arthroplasty. Methods: This prespecified pooled analysis compared the outcomes for the dabigatran 220 mg dose with enoxaparin, which included 4,374 patients. Total VTE (venographic and symptomatic) plus all-cause mortality (primary efficacy), major VTE (proximal deep vein thrombosis [DVT] or non-fatal pulmonary embolism) plus VTE-related death, and bleeding events were evaluated. Efficacy analysis was based on the modified intention-to-treat (ITT) population and safety analysis was based on all treated patients. The common risk difference (RD) for dabigatran versus enoxaparin was estimated using a fixed effects model. Results: Total VTE and all-cause mortality occurred in 6.8 % (114/1,672) and 7.7 % (129/1,682) (RD:-0.8 %, 95 % confidence interval [CI] -2.6 to 0.9) for dabigatran and enoxaparin, respectively. Major VTE plus VTE-related mortality occurred in 2.7 % (46/1,714) and 4.0 % (69/1,711) (RD: -1.4 %, 95 % CI -2.6 to -0.2) of patients receiving dabigatran 220 mg and enoxaparin, respectively. Major bleeding occurred in 1.7 % (37/2,156) and 1.3 % (27/2,157) (RD: 0.5 %, 95 % CI -0.2 to 1.2), for dabigatran and enoxaparin respectively. Conclusions: Extended prophylaxis with oral dabigatran 220 mg once daily was as effective as enoxaparin 40 mg once daily in reducing the risk of total VTE and all-cause mortality after total hip arthroplasty, with a similar bleeding profile. The clinically relevant outcome of major VTE and VTE-related death was significantly reduced with dabigatran versus enoxaparin. Trial registration: NCT00657150 and NCT00168818 [ABSTRACT FROM AUTHOR]

Background: There is a high prevalence of blood product transfusions in orthopedic surgery. The reported prevalence of red blood cell transfusions in unselected patients undergoing hip or knee replacement varies between 21% and 70%. We determined current blood loss and transfusion prevalence in total hip and knee arthroplasty when tranexamic acid was used as a routine prophylaxis, and further investigated potential predictors for excessive blood loss and transfusion requirement. Methods/materials: In total, 193 consecutive patients undergoing unilateral hip (n = 114) or knee arthroplasty (n = 79) were included in a prospective observational study. Estimated perioperative blood loss was calculated and transfusions of allogeneic blood products registered and related to patient characteristics and perioperative variables. Results: Overall transfusion rate was 16% (18% in hip patients and 11% in knee patients, p = 0.19). Median estimated blood loss was significantly higher in hip patients (984 vs 789 mL, p < 0.001). Preoperative hemoglobin concentration was the only independent predictor of red blood cell transfusion in hip patients while low hemoglobin concentration, body mass index, and operation time were independent predictors for red blood cell transfusion in knee patients. Conclusions: The prevalence of red blood cell transfusion was lower than previously reported in unselected total hip or knee arthroplasty patients. Routine use of tranexamic acid may have contributed. Low preoperative hemoglobin levels, low body mass index, and long operation increase the risk for red blood cell transfusion. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: The RECORD programme compared oral rivaroxaban with enoxaparin for prevention of venous thromboembolism after elective total hip or knee replacement. This analysis compared the safety of concomitant use of specified medications with rivaroxaban and enoxaparin by evaluating postoperative bleeding rates from the pooled RECORD1–4 data. Materials and methods: The co-medications were non-steroidal anti-inflammatory drugs and platelet function inhibitors, including acetylsalicylic acid (no dose restriction). The endpoints evaluated were the composite of major and non-major clinically relevant bleeding and any bleeding occurring after first oral study drug intake. The time relative to surgery was stratified into three time periods: day 1–3, day 4–7 and after day 7. Relative bleeding rate ratios for co-medication use versus non-use were derived using stratified Mantel–Haenszel methods and compared between rivaroxaban and enoxaparin groups. Results: Co-medication use with rivaroxaban or enoxaparin resulted in non-significant increases in bleeding events. Respective rate ratios were not significantly different between rivaroxaban and enoxaparin for all bleeding endpoints with concomitant use of non-steroidal anti-inflammatory drugs (any bleeding, 1.22 vs 1.22; major and non-major clinically relevant bleeding, 1.28 vs 0.90) and with concomitant use of platelet function inhibitors/acetylsalicylic acid (any bleeding, 1.32 vs 1.40; major and non-major clinically relevant bleeding, 1.11 vs 1.13). Conclusions: This explorative analysis indicates that there is no significant increase in bleeding risk for rivaroxaban compared with enoxaparin when co-administered with non-steroidal anti-inflammatory drugs or acetylsalicylic acid, although, because of low usage, the experience with platelet function inhibitors (except acetylsalicylic acid) was limited. [Copyright &y& Elsevier]

Background: This phase 3 trial compared the efficacy and safety of rivaroxaban, an oral direct inhibitor of factor Xa, with those of enoxaparin for extended thromboprophylaxis in patients undergoing total hip arthroplasty. Methods: In this randomized, double-blind study, we assigned 4541 patients to receive either 10 mg of oral rivaroxaban once daily, beginning after surgery, or 40 mg of enoxaparin subcutaneously once daily, beginning the evening before surgery, plus a placebo tablet or injection. The primary efficacy outcome was the composite of deep-vein thrombosis (either symptomatic or detected by bilateral venography if the patient was asymptomatic), nonfatal pulmonary embolism, or death from any cause at 36 days (range, 30 to 42). The main secondary efficacy outcome was major venous thromboembolism (proximal deep-vein thrombosis, nonfatal pulmonary embolism, or death from venous thromboembolism). The primary safety outcome was major bleeding. Results: A total of 3153 patients were included in the superiority analysis (after 1388 exclusions), and 4433 were included in the safety analysis (after 108 exclusions). The primary efficacy outcome occurred in 18 of 1595 patients (1.1%) in the rivaroxaban group and in 58 of 1558 patients (3.7%) in the enoxaparin group (absolute risk reduction, 2.6%; 95% confidence interval [CI], 1.5 to 3.7; P<0.001). Major venous thromboembolism occurred in 4 of 1686 patients (0.2%) in the rivaroxaban group and in 33 of 1678 patients (2.0%) in the enoxaparin group (absolute risk reduction, 1.7%; 95% CI, 1.0 to 2.5; P<0.001). Major bleeding occurred in 6 of 2209 patients (0.3%) in the rivaroxaban group and in 2 of 2224 patients (0.1%) in the enoxaparin group (P=0.18). Conclusions: A once-daily, 10-mg oral dose of rivaroxaban was significantly more effective for extended thromboprophylaxis than a once-daily, 40-mg subcutaneous dose of enoxaparin in patients undergoing elective total hip arthroplasty. The two drugs had similar safety profiles. (ClinicalTrials.gov number, NCT00329628.) N Engl J Med 2008;358:2765-75. [ABSTRACT FROM AUTHOR]

This article reports on a clinical trial assessing the oral, direct thrombin inhibitor dabigatran etexilate against enoxaparin as a prophylactic to reduce the risk of venous thromboembolism following total hip replacement surgery. The study found no significant differences in bleeding rates or in increases in liver enzyme concentrations or of acute coronary events during the study period which was just over one month. The authors conclude that oral dabigatran etexilate was as effective as enoxaparin in reducing the risk of a thromboembolism in the patients who had undergone total hip replacement surgery.

In an analysis of the Melagatran Thrombosis Prophylaxis in Orthopedic Surgery (METHRO) III study, we evaluated whether concomitant administration of aspirin (ASA) and non-steroidal anti-inflammatory drugs (NSAIDs) with the direct thrombin inhibitor melagatran/ximelagatran or the low-molecular-weight heparin enoxaparin increased bleeding in patients undergoing major joint surgery. Further objectives were to compare the influence of the timing of initial postoperative administration of melagatran/ximelagatran on bleeding in orthopedic patients receiving ASA/NSAIDs and in comparison with the preoperative administration of enoxaparin. ASA or NSAIDs in conjunction with melagatran/ximelagatran or enoxaparin did not increase bleeding. Bleeding rates were not significantly different, irrespective of the timing of the initial postoperative dose of melagatran/ximelagatran (4–8 vs. 4–12 h) when compared with preoperative (12 h) administration of enoxaparin. Transfusion rates were significantly lower with administration of melagatran/ximelagatran compared with enoxaparin. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Aims To describe the pharmacokinetic–pharmacodynamic (PK–PD) characteristics of the direct thrombin inhibitor dabigatran in hip replacement patients by assessing coagulation parameters activated partial thromboplastin time (aPTT) and ecarin clotting time (ECT), interindividual variability and factors affecting PD responses. Methods BISTRO I patients received oral dabigatran etexilate postsurgery for 6–10 days. Dabigatran plasma concentrations and aPTT/ECT were measured on the day of surgery, on subsequent days and at steady state. PK–PD characteristics of the dabigatran–aPTT/ECT relationships were evaluated using NONMEM V. Results The dabigatran concentration–aPTT relationship was described combining a linear and an Emax model. Mean baseline aPTT was 33.4 s and Emax (maximum increase in aPTT contributed by the Emax model) was 26.9 s. The dabigatran concentration needed to attain 50% of maximum effect (EC50) was 94.7 ng ml−1 and the mean slope of the linear concentration–response relationship (SLOP) was 0.0509 s ng−1 ml−1. Baseline aPTT and Emax were highest following surgery and declined with time. The dabigatran concentration–ECT relationship fitted a linear model. Mean baseline ECT was 28 s and decreased with time; 50% of the maximum effect was observed after 2.9 days. SLOP decreased from 0.38 to 0.27 s ng−1 ml−1 with a half-life of 1.1 day, indicating greater PD effects on the day of surgery. Interindividual and residual variability was low. Covariates could not explain variability of this model. Conclusions aPTT and ECT prolongation were directly correlated with dabigatran concentrations. Blood coagulation prolongation was most pronounced following surgery. Data suggest that ECT provides a more precise description of the anticoagulant effect than aPTT. [ABSTRACT FROM AUTHOR]

Dabigatran etexilate is an oral low-molecular-weight direct thrombin inhibitor. Following oral administration, dabigatran etexilate is rapidly converted to its active form, dabigatran. The authors investigated the absorption, distribution, and elimination of a single 150-mg dose capsule formulation of dabigatran etexilate in healthy volunteers and patients undergoing total hip replacement. In an open-label, 3-way crossover study, dabigatran etexilate was administered to 18 male volunteers in the fasted state, after administration of food and with coadministration of the proton pump inhibitor, pantoprazole. In a subsequent multicenter, open-label study, 59 patients received a single dose of dabigatran etexilate, administered 1 to 3 hours following total hip replacement. In healthy volunteers, food had no effect on the extent of absorption of dabigatran etexilate, although there was reduced interindividual variability for dabigatran maximum plasma concentration and AUC0-∞. A decrease in the mean dabigatran AUC0-∞(904 to 705 ng•h/mL) occurred with coadministration of pantoprazole. In patients undergoing total hip replacement, immediate onset of absorption was seen with the maximum plasma concentration of dabigatran occurring after 6 hours. The AUC0-24of dabigatran was 88% of the steady-state AUC using a preliminary tablet formulation and 106% of that seen in the healthy volunteer study. Compared with healthy volunteers, the postoperative profile was flattened with delayed peak concentrations. In summary, administration of the dabigatran etexilate capsule with food has no effect on the extent of dabigatran absorption, with a moderate decrease when coadministered with pantoprazole. Adequate plasma concentrations of dabigatran were seen with early postoperative administration of the dabigatran etexilate capsule. These pharmacokinetic characteristics confirm the suitability of this oral solid dosage form for use in future clinical trials. [ABSTRACT FROM PUBLISHER]

El artículo habla del riesgo de tromboembolismo venoso (TEV) en los pacientes con una implantación de prótesis totales de cadera y de rodilla. Para disminuir este riesgo, se han utilizado varias sustancias de profilaxia, específicamente el uso del fondaparinux. El fondaparinux es el único fármaco aprobado en los Estados Unidos para la profilaxis a corto y largo plazo de las fracturas de cadera.

Patients undergoing total hip or total knee replacement are at high risk of venous thromboembolism (VTE), and are therefore considered to be populations well suited for the evaluation and dose optimisation of new anticoagulants. Deep vein thrombosis may lead to life-threatening pulmonary embolism, disabling morbidity in the form of the post-thrombotic syndrome, and risk of recurrent thrombotic events. There is increasing evidence that anticoagulant treatment for the prevention of VTE should be extended from 1 to at least 4 weeks after surgery. Anticoagulation with vitamin K antagonists (such as warfarin), low molecular weight heparin or unfractionated heparin effectively lowers the risk of VTE, but these anticoagulants have limitations such as the need for coagulation monitoring and subsequent dose adjustment (vitamin K antagonists), difficulty of continuing prophylaxis out of hospital because of the requirement for parenteral administration, and risk of heparin-induced thrombocytopenia. The development of new anticoagulants has been pursued with the aim of finding more effective, safer and/or more convenient therapies.___TAGSTART___BR___TAGEND___Thrombin is a central regulator in the coagulation and inflammation process and several direct thrombin inhibitors (DTIs) with distinct pharmacological profiles, as well as pharmacological differences from the conventional anticoagulants, are currently in clinical use for certain indications or are under development. Clinical experience with parenterally administered DTIs has accumulated since the mid 1990s, although only desirudin (a recombinant hirudin) is currently approved for use in patients undergoing orthopaedic surgery. Two oral DTIs, ximelagatran and dabigatran etexilate, are in clinical development. Dabigatran etexilate has recently been evaluated in phase II clinical trials in patients undergoing total hip replacement. Several large phase III trials have now demonstrated the efficacy and safety of ximelagatran in the prevention of VTE following total hip or knee replacement. Ximelagatran can be used with an oral fixed dose without the need for coagulation monitoring or dose adjustment. Hence, it offers significant potential to facilitate the management of anticoagulation in or out of hospital. [ABSTRACT FROM AUTHOR]

Summary: Background: Heparins substantially reduce the risk of thromboembolic complications after total hip or knee replacement. However, they can be given only by injection and have several other drawbacks. We did a multicentre, randomised, double-blind study to examine the dose-response relation of subcutaneous melagatran, a direct thrombin inhibitor, followed by oral ximelagatran as thromboprophylaxis after total hip or knee replacement. We aimed to compare the efficacy and safety with that of dalteparin. Methods: Of 1900 patients, 1495 were assigned to four dose categories of subcutaneous melagatran from just before surgery (1.00 mg, 1.50 mg, 2.25 mg, or 3.00 mg twice daily) followed from the day after surgery by oral ximelagatran (8 mg, 12 mg, 18 mg, or 24 mg twice daily). 381 patients were assigned subcutaneous dalteparin 5000 IU once daily, from the evening before surgery. Bilateral venography was done at 7-10 days, and clinically suspected venous thromboembolism (VTE) was confirmed radiologically. The primary endpoint was the rate of deep-vein thrombosis and pulmonary embolism (PE). Analyses were by intention to treat. Findings: 1876 patients underwent total replacement of hip (n=1270) or knee (n=606); evaluable venograms were obtained in 1473 (79%). Four patients without evaluable venograms had PE. Overall, a significant dose-dependent decrease in VTE was seen with melagatran/ximelagatran (lowest to highest group: 111 [37.8%], 70 [24.1%], 71 [23.7%], and 43 [15.1%]; p=0.0001); there were also significant relations for both total hip and total knee replacement individually. The frequency of VTE was significantly lower with the highest dose of melagatran/ ximelagatran than with dalteparin (15.1% vs 28.2%, p<0.0001). There were no reoperations due to bleeding and no critical organ bleeding. Excessive surgical bleeding was uncommon but more frequent in the highest dose group. Interpretation: This sequential therapy was effective and safe in patients... [ABSTRACT FROM AUTHOR]

The first clinical studies evaluating the safety and efficacy of melagatran, a novel, direct thrombin inhibitor, given subcutaneously as prophylaxis for venous thromboembolism (VTE) following total hip (THR) or total knee replacement (TKR) are reported. In Study I, 66 patients received subcutaneous melagatran (1.5–6 mg bid) in a poloxamer depot formulation, and in Study II, 104 patients received subcutaneous melagatran (2–4 mg bid) in saline or as a depot formulation in cyclodextrin. Treatment was given for 8–11 days, with the first dose administered immediately before surgery. Deep vein thrombosis (DVT) was assessed using mandatory bilateral venography on the last day of treatment, and pulmonary scintigraphy was performed if required. Bleeding complications occurred in the only patient who received melagatran 6 mg, and this dose-arm was discontinued. The frequency of VTE was low (12/129=9%, 95% confidence interval [CI]: 5–16%). Eight patients (6%) had distal DVT, three (2%) had proximal DVT, and in one patient (1%) pulmonary embolism (PE) was verified. In conclusion, subcutaneous melagatran 1.5–4.5 mg bid in saline or depot formulation was well tolerated and resulted in a low frequency of VTE. [Copyright &y& Elsevier]

Presents a study on the efficacy of dose levels of CGP 393993, or recombinant hirudin, as compared to unfractionated heparin in the prevention of thromboembolic events following total hip replacement surgery. Patients and methods involved in the study; Findings that CGP 393993 reduced the frequency of deep-vein thrombosis more often than heparin did; Other details of the study.

Abstract: Introduction: Three pivotal phase 3 trials have demonstrated that oral dabigatran etexilate showed similar safety and efficacy to enoxaparin 40mg once daily (qd) for venous thromboembolism (VTE) prevention in patients undergoing total knee or hip replacement. Obesity is an established independent risk factor for VTE. Methods: A post-hoc pooled analysis of the three trials was performed to evaluate the safety and efficacy of dabigatran 220mg qd versus enoxaparin 40mg qd in patients with a normal body mass index (BMI) of >20–25kg/m2, pre-obese patients (BMI >25–30kg/m2) and obese patients (BMI >30kg/m2). The primary efficacy endpoint was major VTE and VTE-related mortality; safety endpoints included major, clinically relevant, or any bleeding events. Results: The mean BMIs for patients in the dabigatran and enoxaparin arms from all three trials, separately, were between 27.5 and 29.9kg/m2. Of the participants, 1417 (24.9%) had a normal BMI, 2373 (41.7%) were pre-obese and 1826 (32.1%) obese. In patients with normal BMI, the rates of the primary efficacy endpoint were significantly lower in the dabigatran than in the enoxaparin group (2.1% versus 4.3%; OR 0.48; 95% CI 0.24–0.97, P =0.037). No significant difference between dabigatran and enoxaparin in the primary efficacy endpoint was observed in the other subgroups. Bleeding rates were also similar between treatments for BMI subgroups. Conclusions: Dabigatran is an effective thromboprophylactic therapy for normal, pre-obese and obese patients, and outcomes in patients with a BMI >25kg/m2 do not differ from the overall population. [Copyright &y& Elsevier]

Background: Patients who undergo total hip replacement have a high risk of thromboembolic complications. Recombinant hirudin (desirudin), a specific inhibitor of thrombin, represents a new development in antithrombotic therapy. We compared the efficacy and safety of desirudin with those of a low-molecular-weight heparin (enoxaparin) for the prevention of thromboembolic complications in patients undergoing primary total hip replacement. Methods: Both treatments, which were assigned in a randomized, double-blind manner, were started preoperatively: enoxaparin on the evening before surgery, and desirudin within 30 minutes before the start of surgery. The dose of desirudin was 15 mg subcutaneously twice daily, and the dose of enoxaparin was 40 mg subcutaneously once daily. The duration of treatment was 8 to 12 days. Deep-vein thrombosis was verified by bilateral venography performed at the end of the treatment period or earlier, if there were clinical signs of deep-vein thrombosis. Results: At 31 centers in 10 European countries, 2079 eligible patients were randomly assigned to receive desirudin or enoxaparin. A total of 1587 patients were included in the primary analysis of efficacy. In the desirudin group, as compared with the enoxaparin group, there was a significantly lower rate of proximal deep-vein thrombosis (4.5 vs. 7.5 percent, P = 0.01; relative reduction in risk, 40.3 percent) and a lower overall rate of deep-vein thrombosis (18.4 vs. 25.5 percent, P = 0.001; relative reduction in risk, 28.0 percent). The safety profiles were similar in the two treatment groups. Conclusions: When administered 30 minutes before total hip replacement, desirudin is more effective than enoxaparin in preventing deep-vein thrombosis. (N Engl J Med 1997;337:1329-35.) [ABSTRACT FROM AUTHOR]

Background: Postoperative neurocognitive decline is a frequent complication in adult patients undergoing major surgery with increased risk for morbidity and mortality. The mechanisms behind cognitive decline after anaesthesia and surgery are not known. We studied the association between CSF and blood biomarkers of neuronal injury or brain amyloidosis and long-term changes in neurocognitive function.Methods: In patients undergoing major orthopaedic surgery (knee or hip replacement), blood and CSF samples were obtained before surgery and then at 4, 8, 24, 32, and 48 h after skin incision through an indwelling spinal catheter. CSF and blood concentrations of total tau (T-tau), neurofilament light, neurone-specific enolase and amyloid β (Aβ1-42) were measured. Neurocognitive function was assessed using the International Study of Postoperative Cognitive Dysfunction (ISPOCD) test battery 1-2 weeks before surgery, at discharge from the hospital (2-5 days after surgery), and at 3 months after surgery.Results: CSF and blood concentrations of T-tau, neurone-specific enolase, and Aβ1-42 increased after surgery. A similar increase in serum neurofilament light was seen with no overall changes in CSF concentrations. There were no differences between patients having a poor or good late postoperative neurocognitive outcome with respect to these biomarkers of neuronal injury and Aβ1-42.Conclusions: The findings of the present explorative study showed that major orthopaedic surgery causes a release of CSF markers of neural injury and brain amyloidosis, suggesting neuronal damage or stress. We were unable to detect an association between the magnitude of biomarker changes and long-term postoperative neurocognitive dysfunction. [ABSTRACT FROM AUTHOR]

This article presents the results of a study comparing the use of the anticoagulant medications rivaroxaban and enoxaparin following total hip replacement surgery, or hip arthroplasty. These medications were administered to prevent venous embolisms, or blockages, following total hip replacement. This trial compared the short term use of enoxaparin with the long term use of rivaroxaban. The incidence of deep vein thrombosis and pulmonary embolism in the two experimental groups was studied. The researchers conclude that thromboprophylaxis was more effective with the use of rivaroxaban than it was with enoxaparin.