Anesthesiologists have long known that accidental puncture of the dural membrane during epidural administration causes severe postpartum headache. They believed, however, that once the woman recovered, that’s the end of it.
It turns out that’s not true. Evidence is mounting that dural puncture can cause long-term, recurrent, debilitating headaches, backaches, or both.
What is dural puncture, and why does it cause symptoms? What is the research uncovering about its potential long-term effects? Let’s answer those questions. Then, I’ll end, as I usually do with a “Take Away” section giving you some ways to make use of what you’ve learned.
What Is Dural Puncture and Why Does It Cause Symptoms?
The spinal cord is wrapped in a protective sheath called the “dural membrane” or “dura” for short. To administer an epidural, the anesthesiologist slips a needle between the spinal vertebrae into the space to the outside—“epi”—of this membrane, hence, the name “epidural.” The needle is big enough to pass a small tube (catheter) through it. Once the catheter is in place, the needle is withdrawn, and the catheter is used to deliver the anesthetic into the epidural space.
In about 1% of epidural procedures,3 the needle goes too deep and pierces a hole in the dura, which allows the cerebrospinal fluid that bathes the spinal cord and brain to leak out. And because the epidural needle needs to be big enough to pass the catheter through it, the hole the puncture makes can leak enough fluid to cause a drop in cerebrospinal fluid pressure. In about 80% of women,1, 4-6 this drop in fluid pressure results in a “post”—meaning “after”—dural puncture headache during the postpartum period. The headache is almost always an incapacitating headache whose defining characteristic is that it gets worse when upright.
Doctors aren’t sure why the loss of pressure causes excruciating headache.6 They think it has something to do with the resultant pull on pain-sensitive tissues. Researchers speculate that the reason for ongoing headaches (or backache) may be that the puncture doesn’t heal completely and continues to leak, or, possibly, similar to other chronic headache syndromes, the tissues become sensitized and prone to recurring symptoms.
What Do Studies Tell Us about Dural Puncture and Ongoing Symptoms?
Note: Two of the four studies I’m using as sources are prospective studies. In prospective studies, investigators conceive of the study; determine what outcomes will be measured, when they will be measured, and by what means; recruit participants; and collect baseline data before any the participants have developed the outcome of interest. Participants are then followed into the future, hence the name “prospective.” This gives prospective studies advantages over studies after the fact that depend on gleaning data from databases or on study participants’ recall. Because of their strengths, I’ll note when I’m reporting results from prospective studies.
- Women who developed a post-dural puncture headache were more likely to be readmitted to the hospital for headache than women not experiencing post-dural puncture headache (30 per 1000 vs. 4 per 1000).2
- Women who don’t develop a post-dural puncture headache may still develop recurrent headache later.6
- Having a history of occasional headaches or backaches doesn’t increase the risk of having dural-puncture related ongoing headaches.4 We don’t know, however, whether women who have headache syndromes are at greater risk.6
- One of the prospective studies found that women with dural puncture were more likely not to be breastfeeding at two months postpartum (56% vs. 84%).1 The study doesn’t tell us the percentages of women breastfeeding at hospital discharge, though, so we don’t know whether the difference in breastfeeding rates is due to an initial post-dural puncture headache, ongoing headaches, or both.
- Here’s what the research tells us about developing recurrent headaches:
- All four studies found that women with dural puncture were more likely to report recurring headaches compared with women having uneventful epidurals.1, 4-6 This held true for the longest period of follow up, which was 18 months.
- One of the prospective studies found that the percentage of women with dural puncture reporting 15 or more headache days over the previous 3-month period remained constant (58%-60%) over the 18-month follow-up period.4 This suggests that experiencing recurrent headaches may be permanent.
- Women who had dural puncture were more likely to report that their headaches were severely painful or disabling compared with women having uneventful epidurals.1, 4, 6
- Studies disagreed on whether headache severity in women experiencing recurring headaches after dural puncture declined over time. The prospective study measuring percentages of women experiencing frequent headaches found that the percentage of women who rated their headaches as “severe” did not change over the 18-month follow-up period.4 The other prospective study, which only included women experiencing disabling headaches, found that the percentage declined from 74% at 2 months to 45% at 12 months.1
- Here’s what the research tells us about developing chronic backache:
- Chronic backache occurs more commonly in women with dural puncture compared with women having uncomplicated epidurals, although not as commonly as recurrent headaches.4-6
- Women who had dural puncture were more likely to experience disabling backache compared with women who had uncomplicated epidurals.4, 6
- One of the prospective studies reported that the percentage of women with dural puncture who reported chronic backache remained constant (45%-49%) over the 18-month follow-up.4 This suggests that experiencing chronic backache may be permanent.
- The same prospective study found that the percentage of women reporting that their backache pain was severe didn’t decline over time.4
- Having an epidural blood patch to treat post-dural puncture headache reduces the percentage of women experiencing recurrent headaches and severe headaches compared with women not having an epidural blood patch.4, 6 Epidural blood patch probably reduces the percentage of women experiencing backache as well.4, 6
- With accidental dural puncture occurring in 1% of epidurals and 60% of women in whom it does experiencing frequent recurrent headaches and about 50% experiencing chronic backache, the odds of experiencing recurrent headache or chronic backache from an epidural are 6 and 5 per 1000 women having an epidural, respectively. These complications are rare but are serious enough that the possibility of experiencing them may influence your decision whether to plan on having an epidural or to cope with labor pain by other means.
- Having a history of occasional headaches or backaches doesn’t increase your risk of recurring backache or headache if you experience a dural puncture; however, whether having a preexisting headache or backache syndrome increases your risk is unknown. If this applies to you, you may want to factor it in when considering whether you want an epidural.
- An epidural blood patch partially protects against developing recurrent headache or chronic backache. If you experience post-dural puncture headache soon after birth, you may wish to request this procedure if it isn’t offered to you.
- Dural puncture is not currently recognized as a possible cause of recurrent headache or chronic backache. If you decide to seek medical help for new or worsened headaches or backaches after having an epidural or spinal, it is likely that your doctor won’t know that dural puncture is a possible cause. You may wish to discuss this possibility with your doctor as it could affect your diagnosis and management.
1. Ansari JR, Barad M, Shafer S, et al. Chronic disabling postpartum headache after unintentional dural puncture during epidural anaesthesia: a prospective cohort study. Br J Anaesth 2021;Clinical Investigation/Articles in Press.
2. Guglielminotti J, Landau R, Li G. Major Neurologic Complications Associated With Postdural Puncture Headache in Obstetrics: A Retrospective Cohort Study. Anesth Analg 2019;129(5):1328-36.
3. Hoefnagel A, Yu A, Kaminski A. Anesthetic Complications in Pregnancy. Crit Care Clin 2016;32(1):1-28.
4. Niraj G, Mushambi M, Gauthama P, et al. Persistent headache and low back pain after accidental dural puncture in the obstetric population: a prospective, observational, multicentre cohort study. Anaesthesia 2021;76(8):1068-76.
5. Ranganathan P, Golfeiz C, Phelps AL, et al. Chronic headache and backache are long-term sequelae of unintentional dural puncture in the obstetric population. J Clin Anesth 2015;27(3):201-6.
6. Webb CA, Weyker PD, Zhang L, et al. Unintentional dural puncture with a Tuohy needle increases risk of chronic headache. Anesth Analg 2012;115(1):124-32.