Neuraxial anesthesia refers to the administration of local anesthetic in or around the central nervous system (CNS), which blocks sensation for a certain region of the body. This type of anesthesia is often used for procedures in the lower body, sometimes in combination with general anesthesia (1). One potential side effect of neuraxial anesthesia and some spinal procedures is post dural puncture headache, and though advancements in knowledge and technology have drastically reduced its incidence, this condition causes serious discomfort and can negatively impact patient recovery (1-4).
To understand post dural puncture headache, it is necessary to understand the anatomy of the meninges in the spine. Within the spinal column, the spinal cord is covered by three membranes – “meninges” – which are the dura mater (outermost), arachnoid mater, and pia mater (innermost). Cerebrospinal fluid (CSF) circulates within the meninges, as well as certain parts of the brain (1-3). Epidural anesthesia, which is one of the major subcategories of neuraxial anesthesia, delivers anesthetic to the space outside of the dura mater. Spinal anesthesia, the other major subcategory, delivers anesthetic to the space between the arachnoid and pia mater (1,2).
Procedures that puncture the meninges, such as the administration of spinal anesthesia, have been linked to severe headaches when the patient is in the upright position. Procedures in the epidural space may inadvertently puncture the dura and cause post dural puncture headache as well (1-5). Patients may also experience dizziness, nausea and vomiting, and auditory or visual disturbances (2,3,5). There are several related hypotheses as to what causes these symptoms. Meningeal puncture allows CSF to leak out faster than it can be replenished naturally. Headache may be caused by resulting intracranial hypotension, compensatory vasodilation of vessels in the CNS, and/or mechanical stimulation of pain-sensitive structures in the skull due to the changing environment (2-5). Regarding the fact that post dural puncture headache tends to be more severe when upright, this is thought to be because the decreased level of CSF is magnified by gravity pulling the remaining fluid down and away from the brain.
Several risk factors for post dural puncture headache have been identified. Young adults, women, lower BMI individuals, and those who experience chronic headache are more likely to experience this side effect after a spinal procedure. A more experienced provider performing the procedure, proper technique as elucidated by research, and smaller needle size are associated with lower risk (2,3,5). Accurate needle positioning can be more challenging in patients with obesity due difficulty palpating bony landmarks, which can lead to accidental dural puncture, but otherwise, higher BMI is actually associated with lower risk – one hypothesis for this pattern is that higher BMI results in higher intra-abdominal pressure that helps to counteract CSF leakage (3).
The incidence of post dural puncture headache at the advent of neuraxial anesthesia was extremely high. However, research has revealed ways in which spinal procedure techniques can be modified to improve outcomes. These include smaller needles, non-cutting needles, and provider skill in the form of first pass success (3,5).
Treatment for this condition is still a topic of research; currently accepted approaches include inducing vasoconstriction (such as with caffeine) and placing a “blood patch” to generate a clot that blocks the puncture. Note, however, that post dural puncture headache does resolve on its own given time (2,4).
References
- Olawin AM, Das JM. Spinal Anesthesia. StatPearls [Internet]. 2021. https://www.ncbi.nlm.nih.gov/books/NBK537299/
- Turnbull DK, Shepherd DB. Post‐dural puncture headache: pathogenesis, prevention and treatment. British Journal of Anaesthesia. 2003; 91(5):718–729. DOI:10.1093/bja/aeg231
- Harrington BE, Reina MA. “Postdural puncture headache.” NYSORA. (n.d.). https://www.nysora.com/topics/complications/postdural-puncture-headache/
- Committee on Obstetric Anesthesia. “Statement on Post-Dural Puncture Headache Management.” ASA. 2021. https://www.asahq.org/standards-and-guidelines/statement-on-post-dural-puncture-headache-management/
- Kim JE, Kim SH, Han RJW, et al. Postdural Puncture Headache Related to Procedure: Incidence and Risk Factors After Neuraxial Anesthesia and Spinal Procedures. Pain Medicine. 2021;22(6):1420-1425. DOI:10.1093/pm/pnaa437