Low Molecular Weight Heparin And Postoperative Deep Vein Thrombosis

1981 ◽  
Author(s):  
V V Kakkar ◽  
B Djazaeri ◽  
P Webb ◽  
M Scully ◽  
J Westwick ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Abdominal Surgery ◽  
Unfractionated Heparin ◽  
Lipoprotein Lipase ◽  
Major Abdominal Surgery ◽  
Bleeding Complications ◽  
Low Molecular Weight ◽  
Similar Response ◽  
Equivalent Amount ◽  
Blood Samples

Recent studies have indicated that commercially available heparin is a hetrogenous compound consisting of the molecules of diverse chain length and different molecular weights. Low molecular weight (LMW) heparin has been shown in vitro to possess unique properties which should not only improve its efficacy for preventing post-op DVT but also reduce or eliminate the risk of bleeding complications. The aim of this paper is to report the results of in vivo studies performed to test this hypothesis.Ten healthy volunteers received 5000 USP units of unfractionated heparin (mol. wt. 15,000 daltons) or equivalent amount of LMW heparin (mol. wt. 6000 daltons) subcutaneously. Blood samples were withdrawn 1/2 1, 3 and 5 hours later. These were analysed for anti-thrombotic effect using anti-factor Xa (anti Xa) assay and anticoagulant effect by estimating kaolin cephalin clotting time (KCCT) method. While both the preparations of heparin produced similar response in KCCT assay, LMW heparin was found to be 4 times more active in anti-Xa assay. 30 patients undergoing major abdominal surgery were randomly allocated to receive either 5000 units of unfractionated heparin or equivalent amount of LMW heparin every 12 hourly for 10 days. Blood samples were withdrawn before, during and immediately after surgery and every day during post-op period. These were analysed for anti-thrombin III and heparin concentrations, lipoprotein lipase, fibrinopeptide A, prekallikrein, TxB2 and 6-oxo-PGF1α to assess platelet effect. Significant differences were only observed in lipoprotein lipase and anti-thrombin III concentrations. In ongoing trial 43 patients undergoing major abdominal surgery have received 1500 units of LMW heparin every 12 hourly for 7 post-operative days. Only 1 patient has developed DVT and another wound haematoma. If these results are confirmed in a larger number of patient, then LMW heparin may be ideal drug for prophylaxis against DVT.

Comparison of Continuation of Low-Molecular-Weight Heparin versus Switching to Unfractionated Heparin in the Peripartum

2019 ◽  
Vol 37 (03) ◽  
pp. 304-312 ◽  
Author(s):  
Christopher A. Enakpene ◽  
Kristina N. Pontarelli ◽  
Micaela Della Torre
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Low Molecular Weight Heparin ◽  
Health Science ◽  
Bleeding Complications ◽  
Low Molecular Weight ◽  
Science System ◽  
University Of Illinois ◽  
Therapeutic Anticoagulation ◽  
The University

Objective This study aimed to determine whether switching from low-molecular-weight heparin (LMWH) to unfractionated heparin (UFH) or its continuation in the peripartum affected anesthesia choice or bleeding complications. Study Design A retrospective cohort study of 189 anticoagulated pregnant women who delivered at the University of Illinois at Chicago Hospital and Health Science System from 2005 to 2016. Demography, anesthesia choice, and bleeding complications were compared between the two groups. Results There were 138 (73%) women on LMWH versus 51 (27%) who switched from LMWH to UFH during the peripartum. The demographics were similar, 123 women were on prophylactic: 81 (66%) were on LMWH and 42 (34%) switched to UFH. Of the 66 women on therapeutic anticoagulation, 57 (86%) continued on LMWH, while 9 (14%) switched to UFH. No difference in neuraxial anesthesia type received: 42 (82.4%) versus 108 (79.7%) women (odds ratio: 1.20, 95% confidence interval [CI]: 0.52–2.73, p = 0.837). Bleeding complications more than 1,000 mL, 6 versus 10% (relative risk [RR]: 0.58, 95% CI: 0.17–1.94, p = 0.380) and relaparotomy due to hemoperitoneum, 2% in either group (RR: 0.9, 95% CI: 0.10–8.48, p = 0.930) were similar in the two groups regardless of time of last injection. Conclusion Anesthesia type and rate of bleeding complications were similar between women on LMWH and UFH during the peripartum.

Anti-Xa Potentiating Effect Of Low Molecular Weight Heparin

1981 ◽  
Author(s):  
W Junker ◽  
J Harenberg ◽  
F Fussi ◽  
K Mattes ◽  
R Zimmermann ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Intestinal Mucosa ◽  
Low Molecular Weight Heparin ◽  
Bleeding Complications ◽  
Low Molecular Weight ◽  
Chromogenic Substrate ◽  
Clotting Time ◽  
Blood Samples ◽  
Increased Risk

Recently special attention has been drawn to bleeding complications of commercial heparins in patients with increased risk for haemorrhages. Alternative heparin preparations with high antithrombotic and low haemostaseological properties have been developed. We now report on a new low molecular weight (LMW) heaprin (mean MW 5000, 85 USP/mg), which has been obtained by depolymerisation of a heparin from pig intestinal mucosa (mean MW 15000, 154 USP/mg).In vitro the anti-Xa-activity (chromogenic substrate S2222) was 15% higher for the LMW heparin in a range of 0.01-2.0 USP/ml plasma. No difference was seen on the anti-IIa-activity (thrombin clotting time)and the aPTT for both heparins in the same range. Both Heparins were injected s.c. in a dose of 100, 50 and 25 USP/kg bodyweight into each of six volunteers randomly at weekly intervalIs. The pharmacodynamic effects were controlled for 6-10 hrs by 8-12 blood samples in relation to the dose applied. Increasing dosis the effects of each heparin increased in all test systems. The anti- Xa-activity of LMW heparin was somewhat higher at 100 and 25 USP/kg. At 50 USP/kg the effect of LMW heaprin was in the same range as 100 USP/kg of the original preparation (MW 15000). The factor Ila activity and aPTT were not influenced differently by the two heparins at each dose.The data indicate, that the LMW heparin presented here may have a more pronounced antithrombotic property by a specific anti-Xa-activity than the compaired commercial heparin. This effect is most pronounced at doses, which have only small haemostaseological effects.

Low Molecular Weight Versus Standard Heparin for Prevention of Venous Thromboembolism After Major Abdominal Surgery

1993 ◽  
Vol 37 (5) ◽  
pp. 281???282
Author(s):  
V. V. KAKKAR ◽  
A. T. COHEN ◽  
R. A. EDMONSON ◽  
M. J. PHILLIPS ◽  
D. J. COOPER ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Venous Thromboembolism ◽  
Abdominal Surgery ◽  
Major Abdominal Surgery ◽  
Low Molecular Weight

Low molecular weight versus standard heparin for prevention of venous thromboembolism after major abdominal surgery

The Lancet ◽  
1993 ◽  
Vol 341 (8840) ◽  
pp. 259-265 ◽  
Author(s):  
V.V. Kakkar ◽  
A.T. Cohen ◽  
R.A. Edmonson ◽  
M.J. Phillips ◽  
S.K. Das ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Venous Thromboembolism ◽  
Abdominal Surgery ◽  
Major Abdominal Surgery ◽  
Low Molecular Weight

scholarly journals Prophylaxis of deep-vein thrombosis after lower extremity amputation: Comparison of low molecular weight heparin with unfractionated heparin

2006 ◽  
Vol 21 (3) ◽  
pp. 184-186 ◽  
Author(s):  
Sidney Lastória ◽  
Hamilton A. Rollo ◽  
Winston Bonetti Yoshida ◽  
Mariangela Giannini ◽  
Regina Moura ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Lower Extremity ◽  
Unfractionated Heparin ◽  
Low Molecular Weight Heparin ◽  
Lower Extremity Amputation ◽  
Bleeding Complications ◽  
Low Molecular Weight ◽  
Vein Thrombosis ◽  
Deep Vein ◽  
Extremity Amputation

PURPOSE: To compare the efficacy and safety of a low molecular weight heparin (enoxaparin) with unfractionated heparin (UH) in this prophylaxis. METHODS: Seventy five patients (59 men and 16 women), undergoing major lower extremity amputation (30 above-knee and 45 below-knee), were randomized to be treated with subcutaneous UH (5,000 IU t.i.d.) or enoxaparin (40mg/day) during hospitalization. Prophylaxis was started 12 hours before surgery or, in emergency cases, in the first postoperative day. RESULTS: The two groups were comparable with regard to baseline characteristics. Evaluation of DVT was performed by daily clinical examination and by duplex scanning before and 5 to 8 days after surgery. DVT was documented in the operated limb in 9.75% in patients treated with enoxaparin and in 11.76% in patients treated with UH (p=0.92) and there was one bilateral thrombosis in each group . Bleeding complications were not observed in both groups. CONCLUSION: Enoxaparin and UH were both efficient and safe for the prophylaxis of DVT in patients submitted to lower extremity amputation.

LOW MOLECULAR WEIGHT HEPARIN (Enoxaparin) COMPARED WITH UNFRACTIONATED HEPARIN THRICE DAILY IN PREVENTION OF POSTOPERATIVE THROMBOSIS. A RANDOMIZED MULTICENTRE TRIAL

1987 ◽  
Author(s):  
M Samama ◽  
P Bernard ◽  
J P Bonnardot ◽  
E Tissot ◽  
Y Lanson ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Varicose Veins ◽  
Estrogen Therapy ◽  
Subcutaneous Administration ◽  
Population Characteristics ◽  
Bleeding Complications ◽  
Low Molecular Weight ◽  
Optimal Dosage ◽  
Intention To Treat

Three consecutive randomized open studies have been carried out in 892 patients undergoing abdominal, gynecological, thoracic or urological surgery. They were over 40 years old and presented at least one of the following risk factors for thrombosis: previous thromboembolism, obesity, varicose veins, malignancy (30% in these studies), pre-operative hospitalization over 5 days, estrogen therapy, chronic cardiac disease or bronchitis. The two groups of each trial were well matched with regard to population characteristics. The third trial included higher rate of patients undergoing urologic surgery. Isotopic venous thromboses and bleeding complications were assessed after subcutaneous administration of a low molecular weight (LMW) heparin fragment (Enoxaparin, 1 mg = 100 Anti-Xa I.U.) or unfractionated heparin (UH). The 3 studies compared 3 × 5,000 IU UH daily with 1 × 60 mg, 1 × 40 mg, or 1 × 20 mg LMW heparin daily. Thromboembolic event rates were not significantly different among the groups (UH : 3.6, 2.8, 7.6% respectively compared to LMWH : 3, 2.8, 3.7%). Significant decrease of hematocrit and hemoglobin were only observed in patients receiving 60 mg Enoxaparin (as compared to UH) whilst in the 2 other trials no difference could be evidenced between the 2 populations. The metaanalysis of the three studies on the “intention to treat” patients gave results consistent with those observed in good compliers. The three consecutive studies showed homogeneous results (p = 0.20), the Mantel Haenszel test did not evidence a global difference between Enoxaparin and unfractionated Heparin (p = 0.54). These results suggest that an optimal dosage of 20 mg per day of Enoxaparin is safe and as efficient as UH 5,000 IU × 3 in the prevention of post-operative thrombosis in this population.

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