Observational study on intrathecal and peridural changes after routine spinal and epidural anesthesia in patients...

Epidural bleeding from spinal anesthetics or epidural catheter placement is concerning, especially when anticoagulants are used. Little is known of the natural changes that occur subdurally or epidurally after each of these procedures. To describe the natural history and occurrence of bleeding that may result from these anesthetics with anticoagulants, we studied 16 joint arthroplasty patients who underwent spinal magnetic resonance imaging postoperatively. Seven patients had an epidural catheter, 7 had a straight spinal injection, and 2 had a general anesthetic. All patients received 5 mg of warfarin postoperatively, with dosing to an international normalized ratio of 2.0. Magnetic resonance imaging readings were blinded. No magnetic resonance image demonstrated peridural inflammation or hemorrhage. No difference was observed between the anesthetics. Warfarin did not cause abnormal bleeding. Based on these observations, one should consider bleeding or peridural inflammation to be abnormal after spinal or epidural anesthesia.