[Hemostatic requirements for the performance of regional anesthesia. Workshop on hemostatic problems in regional anesthesia].

There is uncertainty as to which preoperative examinations are necessary before performing regional anesthesia. Therefore an interdisciplinary consensus conference was established to obtain recommendations on some of the open questions related to this topic. Preoperative laboratory examinations are not necessary prior to peripheral nerve blocks near large vessels if these are easy to compress. In patients on anticoagulant therapy direct puncture of the vessel should be avoided. Prior to spinal or epidural anesthesia, no preoperative laboratory examinations are necessary if no anamnestic or clinical evidence of coagulation disorders exists. Otherwise the following examinations are useful: clotting time, prothrombin time, partial thromboplastin time (PTT), and thrombocyte count. Low-dose heparin prophylaxis is no contraindication to spinal or epidural anesthesia. However, in patients at increased risk of bleeding or with low body weight, PTT and thrombocyte count are necessary. Since at present no definite data exist as to the bleeding risk in patients treated with low-molecular-weight heparin prophylaxis, spinal/epidural anesthesia should be performed in controlled studies only under these conditions. This particular precaution seems to be necessary because low-molecular-weight heparin increases levels of plasminogen activators (t-PA) and therefore has fibrinolytic activity. If plasma expanders are administered perioperatively, the highest bleeding risk exists after dextran infusions. There is also an increased bleeding risk if nonsteroidal anti-inflammatory drugs, especially acetylsalicylic acid, are administered repeatedly within 5 days prior to spinal/epidural anesthesia. In these patients preoperative determination of the clotting time appears necessary.(ABSTRACT TRUNCATED AT 250 WORDS)