Accidental dural puncture during epidural blood patch: a narrative review.

Whilst performing an epidural blood patch (EBP) to treat post dural-puncture headache following accidental or intentional dural puncture, the risk of a subsequent accidental dural puncture (ADP) is commonly quoted as 1%. However, a recent review reported only three documented cases. It seems likely that this complication is more common than is acknowledged, yet there is a paucity of literature and an absence of any guidance as to how to proceed in practice. This review addresses three unanswered questions regarding ADP during EBP: what is the incidence; what are the immediate clinical consequences; and what is the optimal clinical management? The incidence may reasonably be estimated to be 0.5-1%. Even on large units, this complication will not be experienced by every consultant anaesthetist during their career. It is likely to occur 20-30 times per year in the United Kingdom, and in greater numbers in those countries with higher epidural rates. Immediately re-attempting an EBP at a different level may be a reasonable management approach which has high efficacy, and is without clear evidence of significant harm. However, the limited evidence means that the risks are poorly characterised, and more data may lead to alternative conclusions. There is uncertainty amongst obstetric anaesthetists about how to manage ADP during EBP. More data and pragmatic guidance, which evolves with further evidence, will ensure optimal care for patients suffering this compound iatrogenic complication.