Regional anesthesia and anticoagulation.
ABSTRACT The perioperative use of neuraxial techniques in the presence of anticoagulation is a controversial issue. There are significant pharmacokinetic differences between anticoagulants that will affect the timing of neuraxial needle insertion or catheter removal. The pharmacologic profiles of commonly used anticoagulants in the perioperative period are reviewed. Studies examining the use of neuraxial techniques in the presence of various anticoagulants are reviewed and evaluated in the context of the American Society of Regional Anesthesia consensus statements.
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ABSTRACT: Expression of the chemokine receptor CXCR4 allows breast cancer cells to migrate towards specific metastatic target sites which constitutively express CXCL12. In this study, we determined whether this interaction could be disrupted using short-chain length heparin oligosaccharides. Radioligand competition binding assays were performed using a range of heparin oligosaccharides to compete with polymeric heparin or heparan sulphate binding to I(125) CXCL12. Heparin dodecasaccharides were found to be the minimal chain length required to efficiently bind CXCL12 (71% inhibition; P<0.001). These oligosaccharides also significantly inhibited CXCL12-induced migration of CXCR4-expressing LMD MDA-MB 231 breast cancer cells. In addition, heparin dodecasaccharides were found to have less anticoagulant activity than either a smaller quantity of polymeric heparin or a similar amount of the low molecular weight heparin pharmaceutical product, Tinzaparin. When given subcutaneously in a SCID mouse model of human breast cancer, heparin dodecasaccharides had no effect on the number of lung metastases, but did however inhibit (P<0.05) tumour growth (lesion area) compared to control groups. In contrast, polymeric heparin significantly inhibited both the number (P<0.001) and area of metastases, suggesting a differing mechanism for the action of polymeric and heparin-derived oligosaccharides in the inhibition of tumour growth and metastases.British Journal of Cancer 09/2007; 97(6):761-8. DOI:10.1038/sj.bjc.6603928 · 4.82 Impact Factor
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ABSTRACT: Unlike neuraxial anesthesia, performing peripheral nerve blocks in the presence of anticoagulation offers a margin of safety. The catastrophic event appears to be bleeding rather than major neurologic injury. In general, superficial limb blocks are not contraindicated in patients receiving anticoagulation. Deeper blocks such as the posterior lumbar plexus block, especially with the use of continuous catheter technique, necessitate a more prudent approach. Careful risk-to-benefit assessment through thorough preoperative evaluation, awareness of perioperative anticoagulation plans, and good knowledge of drug pharmacology should be applied to individual patients.Techniques in Regional Anesthesia [amp ] Pain Management 04/2006; DOI:10.1053/j.trap.2006.04.006
- Seminars in Anesthesia Perioperative Medicine and Pain 09/2003; 22(3):209-217. DOI:10.1016/j.sane.2003.08.002