REGIONAL ANESTHESIA AND THROMBOEMBOLISM P ROPHYLAXIS ANTICOAGULATION/

Performing regional anaesthetics in patients who have or will receive some form of anticoagulation is still discussed controversially. Howev er, spinal or epidural anaesthesia is considered safe during low-dose therapy with unfractioned or low molecular weight heparins as long as the following time intervals between administration of heparin and spi nal/epidural puncture or removal of the catheter are carefully taken i nto account, After unfractioned heparin, placement of a needle or cath eter and removal of the epidural catheter should be delayed for 4 hour s, A subsequent injection of unfractioned heparin can be administered after 1 hour, This includes intraoperative intravenous full heparinisa tion, provided ACT is carefully monitored, In low molecular weight hep arins (LMWH), due to the different pharmacokinetics and pharmacodynami cs, longer time intervals are necessary in order to avoid spinal/epidu ral bleeding complications; After a single subcutaneous injection, pla sma levels of LMWH peak after 4 hours and 50% of peak levels can still be detected after 12 hours, therefore a spinal/epidural puncture or c atheter removal should be delayed for 10-12 hours, Subsequent injectio ns of LMWH should occur at least 4 hours later due to their fibrinolyt ic activity, Routine clotting assays are not necessary, However, if th erapy with unfractioned or LMWH has been administered for more than 5 days, a thrombocyte count should be performed to exclude heparin-induc ed thrombocytopenia. In order to minimize bleeding complications durin g regional anaesthetic techniques, care should be taken to avoid a tra umatic puncture and to postpone surgery, if a bloody tap occured, Alte rnatively, catheters can be placed the night before surgery, Regional anaesthesia in patients with full anticoagulation with either heparin or vitamin K antagonists remains contraindicated.