[Spinal and epidural anesthesia in patients with hemorrhagic diathesis : decisions on the brink of minimum evidence?].

Neuraxial anesthesia is an established and safe procedure in perioperative pain therapy which can help to minimize complications and to improve perioperative outcome. In patients with acquired bleeding disorders by comorbidities or concomitant antithrombotic medication an individual decision should be made based on risks and benefits. A large number of literature references and guidelines help making a decision, for example the recently updated evidence-based guidelines of the American Society of Regional Anesthesia and Pain Medicine for patients receiving antithrombotic or thrombolytic therapy. However, no explicit recommendations or guidelines exist for patients with hemorrhagic diatheses, such as von Willebrand disease (vWD), hemophilia A and B and idiopathic thrombocytopenic purpura (ITP). Published data regarding the safety of neuraxial techniques in these patients is scarce. Neuraxial anesthesia in patients with vWD is only acceptable when coagulation is optimized (substitution of factor concentrates or hemostatic agents depending on the type of vWD) and monitored frequently during the procedure. The only exception might be obstetric patients with vWD type I as coagulation frequently normalizes at the end of pregnancy. In these patients neuraxial anesthesia can often be performed without supplementation of clotting factors.Neuraxial techniques in patients with hemophilia A or B are usually contraindicated. The procedure may only be acceptable if serious reasons exist against general anesthesia. Supplementation of the missing factor to normal levels and monitoring during procedure is essential if neuraxial block is performed.Patients with ITP often present with low platelet counts. Normally, spinal or epidural anesthesia is considered safe if the platelet count is over 80,000/µl. However, the consistently low platelet counts in ITP seem to be less problematic than rapidly falling values due to other diseases, because this is often accompanied by platelet dysfunction or coagulopathy. In several studies neuraxial anesthesia was successfully performed with platelet counts between 50,000 and 80,000/µl. Nevertheless, the minimum safe platelet count for neuraxial blockade remains undefined in these patients.Evidence-based recommendations for neuraxial anaesthesia in patients with hemophilia, vWD or ITP cannot be offered. Each patient has to be treated individually with appropriate caution. This overview is intended to assist in the decision for or against neuraxial anesthesia in these patients, with emphasis on the pathophysiological background, blood investigations and case reports from the literature.