Regional anesthesia and issues of coagulation status.

Regional anesthesia has generally been accepted as safe and is associated with a relatively low incidence of neurological injury. In 1993, the Food and Drug Administration approved the use of low molecular weight heparin for perioperative thromboprophylaxis. In the past 5 years, there has been an alarming increase in the number of intraspinal hematomas and neurological injury associated with its use in patients undergoing neuraxial anesthesia. This article reviews the coagulation cascade, the various laboratory studies used to assess the coagulation system, and issues related to neuraxial block in the patient with perioperative anticoagulation therapy. The various anticoagulant drugs and their potential to cause intraspinal hemorrhage are addressed with special attention paid to low molecular weight heparin. Finally, recommendations for managing the patient who receives these drugs is presented.