Lean body weight is the best scale for venous thromboprophylaxis algorithm in severely obese patients undergoing bariatric surgery.

Severely obese patients undergoing bariatric surgery (BS) are at increased risk for venous thromboembolism (VTE). How standard low molecular weight heparin (LMWH) regimen should be adapted to provide both sufficient efficacy and safety in this setting is unclear. We aimed to compare the influence of four body size descriptors (BSD) on peak anti-Xa levels in BS obese patients receiving LMWH fixed doses to identify which one had the greatest impact. One hundred and thirteen BS obese patients [median body mass index (BMI), 43.3 kg/m2 (IQR, 40.6-48.7 kg/m2)] receiving subcutaneous dalteparin 5000 IU twice daily were included in this prospective monocenter study. Peak steady-state anti-Xa levels were measured peri-operatively following thromboprophylaxis initiation. Only 48% of patients achieved target anti-Xa levels (0.2-0.5 IU/ml). In univariate analysis, age, gender, total body-weight (TBW), lean body-weight (LBW), ideal body-weight (IBW), BMI and estimated glomerural filtration rate (eGFR) were associated with anti-Xa levels. The strongest negative association was observed with LBW (r = -0.56, p < .0001). Receiver operating characteristic curves indicated that among BSD, LBW (cut-off >55.8 kg) had the highest sensitivity (73%) and specificity (69%) to predict sub-prophylactic anti-Xa levels. In multivariate analysis, LBW and eGFR remained associated with anti-Xa levels (ß = -0.47 ±â€¯0.08, p < .0001 and ß = -0.19 ±â€¯0.08; p = .02, respectively). In BS morbidly obese patients receiving LMWH for thromboprophylaxis after BS, LBW and eGFR are the main determinants of anti-Xa level, and could be proposed in LMWH-based thromboprophylaxis dosing algorithms. The efficacy of a LBW-scale based dosing algorithm for optimal VTE prevention deserves further prospective randomized trials.

Southeast asian ovalocytosis: the need for a carefull observation of red cell indices and blood smear.

Southeast asian ovalocytosis (SAO) is characterized by macro-ovalocytes and ovalo-stomatocytes on blood smear. SAO is common in Malaisia and Papua-New-Guinea where upwards to 40 per cent of the population is affected in some coastal region. Inherited in an autosomal dominant way, illness results from deletion of codons 400-408 in SLC4A1 gene which encodes for band 3 erythrocyte membrane protein. This deletion is responsible for an unusual erythrocyte stiffness and oval shape of the cells on blood smear. Heterozygous carriers are usually asymptomatic whereas homozygous are not viable without an intensive antenatal care. Here, we describe 4 patients diagnosed incidentally by cytogram appearance of the Advia® 2120i (Siemens) representing hemoglobin concentration according to red blood mean cellular volume (GR/VCH).

Perioperative thromboprophylaxis in severely obese patients undergoing bariatric surgery: insights from a French national survey.

BACKGROUND: Venous thromboembolism (VTE) is a leading cause of death in obese patients undergoing bariatric surgery (BS), but there is neither consensus nor high-level guidelines yet on VTE prophylaxis in this specific population. OBJECTIVE: We aimed to evaluate patterns of BS perioperative thromboprophylaxis practices. SETTING: French obesity specialized care centers (CSO), which are tertiary care referral hospitals for the most severe cases of obesity METHODS: A detailed questionnaire survey (11 opened, 15 closed questions) investigating their prophylactic schemes of anticoagulation (molecule, dose, weight-adjustment, duration, associated measures, follow-up) was sent to the 37 CSO. RESULTS: Completion rate was 92%. Over 90% of respondents indicated using low molecular weight heparin. Enoxaparin was the most commonly used molecule (89%), twice daily (71%), started mostly 6 hours after BS (74%), whereas fondaparinux (9%), dalteparin (6%), and tinzaparin (6%) were less often prescribed. Dosing varied significantly according to centers from 4000 to 12,000 IU/d, with the most commonly used dose being 8000 IU once daily, 83%, as well as treatment duration (1 week, 9%; 3 weeks, 47%). Half CSO adjusted low molecular weight heparin dose to weight. Biological monitoring was performed in 88%. Only 1 center followed systematically anti-Xa activity. Associated measures such as elastic stoking or intermittent pneumatic compression were used in 32% and 26%, respectively, and both were used in 39%. CONCLUSION: This study finds significant discrepancies in thromboprophylaxis practices in obese patients undergoing BS, particularly with respect to treatment duration and dose adjustment, highlighting the urgent need for improved implementation of existing clinical practice guidelines in this VTE high-risk population.