Epidural blood patch using a catheter. Diagnosis of an unrecognised dural tap.

Twenty five patients were treated with an epidural blood patch for persistent headache, following a known or suspected dural puncture. Fifteen to 20 ml blood was injected into the epidural space through a catheter inserted one space away from the dural puncture. The catheter technique was useful in confirming the clinical diagnosis of previously unrecognised dural tap in six patients with severe headache. It was possible to perform the blood patch single-handed.