The assessment of bleeding risk requires assessment of patient- and procedure-specific characteristics. The extensive venous plexus of the epidural space is vulnerable to trauma from needle puncture, advancement of spinal cord stimulator leads, or epidural and intrathecal catheters. The fragility and caliber of these vessels increase with age and various physiologic or pathologic states. The anatomic narrowing of the spinal canal from a myriad of conditions may lower the threshold for neurologic compression and injury with spinal bleeding. Table 33.2, adapted from the ASRA 2015 guidelines for pain procedures, provides a risk assessment based on type of pain procedure.

Concurrent use of coagulation-altering medications may increase the risk of bleeding without altering coagulation studies. Catheters are placed and removed at the nadir of anticoagulant activity. Additional anticoagulants should not be given immediately after catheter removal. Before initiating neuraxial anesthesia , the patient’s medication list should identify the presence of anticoagulant or antiplatelet therapy. Common anticoagulants encountered in the surgical setting include antiplatelet medications, oral anticoagulants, unfractionated heparin, low molecular weight heparin, serotonin reuptake inhibitors, and herbal preparations.