Epidural blood patch - myths and legends

Abstract

PIDURAL blood patch (EBP) was suggested before even I was born, and has been considered the most effective treatment of post-dural puncture for over 40 years, yet many aspects still fascinate and confuse, and its clinical merit remains controversial. A systematic review of EBP, in the highly respected Cochrane database of systematic reviews, concluded: " At present, except in the context of a randomised controlled trial, we believe that epidural blood patching should be reserved for exceptional cases only (such as) post-dural puncture headache complicated by subdural hemorrhage or disabling headache after one week or more."1 Wow, hands up if you agree! EBP entered practice thanks to the work of a general surgeon, James Gormley, 2 partly because of his serendipitous observation that bloody insertions were less likely to cause headache (although this is probably erroneous!). Knowledge of EBP was disseminated by the American anesthesiologist Anthony DiGiovanni, a legend in my eyes, not least because he, like many of us, had his manuscript rejected by Anesthesiology. The British legend was Selwyn Crawford, who gathered useful observational data and stimulated new research.Given that rigorous investigation is difficult and noticeably lacking, it is not surprising that myths about EBP persist. Textbooks have tended to perpetuate a series of misconceptions about EBP after dural puncture by epidural needles, and data supporting a number of common practices are limited or of questionable validity, making evidence-based practice impossible.To distinguish fact from fiction (or supposition at least), many aspects related to this therapy could be examined. Examples are questions such as: "Should blood culture be performed before EBP?"; and dictums such as: "Perform the EBP at the same or an interspace below the level of dural puncture", "Keep the patient supine for at least two hours after EBP" and: "Avoid straining after an EBP". Confining my comments principally to the obstetric population, I will attempt to identify the strength of evidence in relation to four areas of controversy or misconception:1. The effectiveness of EBP after unintentional dural puncture with an epidural needle. 2. The volume of autologous blood that should be injected for EBP. 3. The optimal timing of EBP. 4. The safety of EBP. 5. The mechanism by which EBP relieves headache." "H Ho ow w e ef ff fe ec ct ti iv ve e i is s a an n E EB BP P a af ft te er r a an n u un ni in nt te en nt ti io on na al l d du ur ra al l p pu un nc ct tu ur re e? ?" " Obstetric anesthesiologists working in busy units with trainees get to become "experts" because they are involved with, or hear about, a few EBP each year. This highlights that our individual exposure to this intervention, over a lifetime, is extremely limited (at least we hope!). Consequently, personal experience and anecdote tend to strongly colour our opinions and practices. The Cochrane review of randomized controlled trials of EBP vs no EBP for treatment of post-dural puncture headache (PDPH), between ...

Complications following large-volume epidural blood patches for postdural puncture headache. Lumbar subdural hematoma and arachnoiditis: initial cause or final effect?

“…In summary, it seems a volume of 10 to 20 mL is deemed an appropriate volume for EBP in the literature, with reasonable success rates of 60% to 75% and very few complications [3,4]. However, because the rate of complications is low, one would need to study thousands of patients to find a single serious consequence of the procedure [7]. One other case described a spinal subdural hematoma with a volume greater than 30 mL [11].…”

“…Degree of CSF loss or dural damage from the initial "wet tap" may influence the success of EBP at any volume. In addition, timing seems to be a very important factor; initial EBPs performed a full 24 hours following dural puncture are more successful [7], even when relatively smaller volumes of blood are used [8].…”

Chronic Back Pain Secondary to a Calcified Epidural Blood Patch

“…The most common complication of EBP is immediate or late back pain. 8 In a long-term follow-up study, 35% of patients reported back pain that subsided within 48 h. 9 This may result from the leakage of blood into the intervertebral ligaments and subcutaneous fat. 7 Rare complications include lower back pain with radicular pain, spinal subdural hematoma, spinal subdural epiarachnoid hematoma (complication of a novel technique involving intentional puncture of the dura), intrathecal hematoma and arachnoiditis, and two cases of neurologic deterioration after EBP to patients with increased intracranial pressure.…”

Post‐delivery postural headache: not always a classical post‐dural puncture headache

“…However, a more extensive investigation with radiological imaging should be considered in cases with less typical symptoms or headache persisting after a first correctly performed EBP. As EBP has been associated with serious complications (2–5), anaesthetists should be more critical when asked to perform this procedure in patients with symptoms inconsistent with PDPH, or when a first procedure has failed. Fortunately, the two EBPs in our patient did not result in catastrophic deterioration.…”

“…Nevertheless, complications may be serious. Aseptic arachnoiditis and meningitis, intracranial hypertension, cauda equina syndrome, bradycardia, pneumocephalus and subarachnoid haematoma have all been described (2–5). Repeat EBP may be necessary in a small percentage of patients.…”