Increased awareness could lead to appropriate diagnosis, prompt treatment, and better patient outcomes.

The purpose was to determine the incidence and prevalence of venous thromboembolism (VTE) in acute leukemia patients from our institution. We conducted a retrospective study on newly diagnosed acute leukemia patients who presented at our institution from November 1999 to May 2005. Descriptive statistics and cross-tabulation were used to describe patient characteristics. Measures of morbidity were used to address VTE risk. Chi-square testing, Fisher's exact testing, Mann–Whitney analyses, or median testing were used to determine between-group differences. Data analyses were conducted using Stata version 11 (Stata Corp., College Station, TX). Two hundred and ninety-nine patients with acute lymphoblastic leukemia (ALL) and 996 patients with acute myeloid leukemia (AML) were included. After excluding patients diagnosed with VTE prior to or at the time of leukemia diagnosis, during the mean time follow-up period of 2.5 years (range: 0.0025–10.3 years), the overall incidence rate of VTE was 3.7 per 100 person-years: 4.2 per 100 person-years for ALL and 3.4 per 100 person-years for AML. Among all patients, the majority (80.6%) developed VTE within 12 months after diagnosis and during thrombocytopenia. The most common VTE was central venous catheter (CVC)-associated upper-extremity deep venous thrombosis. Pulmonary embolism occurred in 15% of ALL patients and 8% of AML patients. VTE recurred in 20.7% of ALL patients and 18.6% of AML patients. VTE occurs frequently in patients with acute leukemia. Studies are needed to identify risk factors for the development and recurrence of VTE among patients with acute leukemia and to establish more effective methods for preventing and treating VTEs in leukemia patients who have thrombocytopenia and/or CVC.

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Low molecular weight heparins (LMWHs) are used for prevention of clotting in the dialysis circuit. The aim of this trial was to define the optimal dose of a new LMWH and to test the efficiency of a single dose at the start of the session. Fifteen patients were treated according to a double blind and crossover design during 4 blocks of 5 consecutive reviparin doses assigned randomly as 50, 60, 70, 85, and 100 IU anti-Xa/kg. Assessment was carried out on screening of fibrin rings or clots in the arterial and venous air traps and on visual detection of fiber in the dialyzer after rinsing. These clinical results were compared to plasmatic anti-Xa activity and thrombin-antithrombin (TAT) complex generation. A standard dose of 70 IU anti-Xa/kg of nadroparin was used as the control. After a bolus of 50 to 100 IU anti-Xa/kg, the occurrence of fibrin rings and clots in the air traps was dependent on three factors: dose of LMWH, time of the session, and patient status. A bolus of 85 IU anti-Xa/kg of reviparin was effective and safe for sessions of 4 h. For this dose, plasmatic anti-Xa activity was 0.96 +/- 0.28 IU/ml at Hour 2 and 0.82 +/- 0.22 IU/ml at Hour 4. TAT complexes are good markers of the activation of the coagulation. They did not increase during a 4 h session after a reviparin bolus of 100 IU/kg. For the same LMWH dose, the trial shows a great variability of the clinical effect and anti-Xa activities from one patient to another. A single dose of 85 IU anti-Xa/kg of reviparin can be used at the start of the dialysis session as a loading dose. We advise adapting the dose during the subsequent sessions according to the appearance of the blood circuit. The benefit of monitoring anti-Xa activity and TAT complexes could be tested in a further trial.

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