Postdural Puncture Headache

Postdural puncture headache (PDPH) may develop after an unintended (accidental) dural puncture, after deliberate dural puncture for spinal anaesthesia or during diagnostic dural punctures performed by other medical specialties. PDPH may sometimes be predictable (patient characteristics, inexperienced operator or co-morbidities), is almost never immediately evident during the procedure, and sometimes presents late, after discharge. Specifically, PDPH severely restricts activities of daily living, patients may be bedridden for several days and mothers may have difficulty in breastfeeding. Although an epidural blood patch (EBP) remains the management technique with greatest immediate success, most headaches resolve over time but may cause mild-severe disability. Failure of EBP after the first attempt is not uncommon, and major complications may occur but are rare. In the current review of the literature, we discuss the pathophysiology, diagnosis, prevention and management of PDPH following accidental or intended dural puncture, and present possible therapeutic options for the future.

Despite advances in procedural techniques and equipment, postdural puncture headache (PDPH) remains a serious complication of labour epidural analgesia after accidental dural puncture (ADP). Often considered a temporary inconvenience, PDPH can be debilitating in the short term. It can also be associated with chronic manifestations and serious complications. The precise underlying mechanisms of PDPH are still incompletely understood, and longstanding beliefs of dysregulation of cerebrospinal fluid (CSF) homeostasis due to CSF fluid loss are currently being challenged. The existence of orthostatic headaches unrelated to CSF loss demands consideration of other mechanisms involved, for instance, related to the autonomic nervous system or the release of calcitonin gene-related peptide (CGRP) associated with activation of the meningeal and cerebral arteries. A multi-society international working group recently provided evidence-based recommendations on the prevention, diagnosis, and management of PDPH resulting from neuraxial procedures. According to the recommendations, there was insufficient evidence to support the routine use of intrathecal catheters or sphenopalatine ganglion blocks to prevent or treat PDPH. Both evidence-based and experimental strategies include stabilizing CSF dynamics through preventing CSF loss, supplementing CSF, or increasing production, and reducing cerebral vasodilation. Future research in PDPH preventive and therapeutic strategies can be facilitated with standardised definitions, interventions, and outcome measures. Analyses should consider various confounding factors and recognise the complex multifactorial nature of pain experience across diverse populations. Clinical care and research on PDPH will demand a multidisciplinary collaborative effort to elucidate the complexities of its pathophysiology and further improve patient outcome and quality of care.

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.

The treatment of postdural puncture headache remains controversial, largely because it is insufficiently evidence based. With high rates of neuraxial block in the obstetric population likely to continue, postdural puncture headache will remain a primary cause of morbidity and increased duration of hospital stay. This review describes new reports of relevance published in 2006 and until October 2007. New evidence justifies epidural blood patch as the treatment of choice for severe postdural puncture headache, but technical aspects such as optimal timing and volume are less clear. Symptomatic medical management remains diverse, with a multitude of therapies often advocated, despite a lack of scientific support. Reports of misdiagnosis and of complications associated with postdural puncture headache and its treatment emphasize the importance of multidisciplinary management and additional investigation, including radiological imaging, when the clinical picture warrants. The key reports in this epoch have shed light on the benefits of careful assessment of postpartum headache and treatment with an epidural blood patch. New management paradigms have been suggested and serious complications continue to be reported.