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Epidural Blood Patch

An epidural blood patch (EBP) is a procedure in which a small volume of autologous blood is injected into a patients epidural space to stop a leak of cerebrospinal fluid (CSF). This leak of CSF is thought to decrease CSF pressure, particularly when the patient is upright, allowing for increased cerebral blood flow via vasodilation producing a characteristic post-dural puncture headache (PDPH or "a spinal headache"). An alternate theory suggests that loss of CSF pressure, particularly with upright posture, creates traction on the cerebral meninges which is continuous with the vertebral meninges.[1][2] PDPHs occur when the dura has been violated. Typically this occurs following a subarachnoid injection (a "spinal"), or from inadvertent puncture of the dura when attempting epidural injection or placement of an epidural catheter. PDPHs can also occur following diagnostic or therapeutic procedures (diagnostic lumbar puncture, lumbar myelogram) or following spinal surgery. EBP is rarely used to treat "spinal" a headache following the creation of a dural rent following spine surgery. The incidence is less than 1% following subarachnoid block performed with a 25-gauge spinal needle. This increases to nearly 36% when using a 20-gauge or 22-gauge needle for diagnostic lumbar puncture. Following inadvertent puncture of the dura with a 17-gauge epidural needle, the incidence of PDPH is approximately 75% to 80%. Risk factors include needle puncture size, age less than 60 years and female gender. Typical onset is 24 to 48 hours following a puncture. A headache is often described as intense, vise-like in the frontal-occipital region and may be accompanied by cranial nerve symptoms of auditory impairment and/or blurred vision. Pathognomonic for PDPH is an aggravation of symptom in an upright position with relief in a supine position. Left untreated more than 90% of PDPHs are self-limiting and will resolve spontaneously in 7 to 10 days. A prophylactic EBP following an inadvertent dural puncture in parturients for epidural catheter placement has not been shown to decrease the incidence of PDPH. Although many treatments including bedrest, analgesics, NSAIDs, hydration, intravenous (IV) caffeine, or consumption of caffeinated products have been used, these produce only temporary relief. The definitive treatment is performing an EBP with approximately 85% success rate. EBP may be repeated and is reported to have a 90% success rate. In rare refractory instances, surgical exploration and placement of fat graft may be considered.[3][4][5]