Headache After Childbirth Epidural a Red Flag for Brain Bleed

Batya Swift Yasgur, MA, LSW

September 25, 2019

Women who experience headaches following epidural anesthesia during childbirth have a greater risk of developing intracranial subdural hematoma, new research shows.

Using a large database to study over 22 million deliveries, investigators found a 100-fold increase in subdural hematoma in women who experienced a headache following epidural, compared with their counterparts with subdural hematoma who did not experience headaches.

"When a patient has a post-dural puncture headache, they are at risk for a subdural hematoma, which can result in serious morbidity and increased mortality and needs to be considered by any clinician looking after these patients," lead author Albert Moore, MD, associate professor, McGill University, Montreal, Canada, told Medscape Medical News.

"The risk is higher in patients who have coagulopathy, previous cerebral arteriovenous malformations, and hypertensive disease, and there is also a possibility that delaying a blood patch may increase the risk of developing a subdural hematoma," he said.

The study was published online September 16 in JAMA Neurology.

No Robust Evidence

"I had read and heard a lot of reports about women who had post-dural puncture headaches, who then developed a subdural hematoma," Moore noted.

"However, these were only case reports and there was no robust evidence to support any association of post-dural puncture headache with subdural hematoma and brain damage," he added.

Moore and his coinvestigators were concerned about this potential association because more than half of all women have epidurals during childbirth — and a significant percentage of them have post-dural puncture headaches.

"So if there really was an association of post-dural puncture headache with subdural hematoma, those who provide epidurals for labor and care for patients with post-dural puncture headaches should be aware," he said.

The goal of the study then was to determine whether there was an association of post-dural puncture headache and subdural hematoma. The investigators also looked at whether there were factors that could potentially increase or decrease the risk of subdural hematoma in these patients.

"The most important thing we were wondering about was the epidural blood patch, because a blood patch is something that can be offered and, if it is protective, could help a lot of these patients," he said.

The investigators analyzed data from the US Agency for Healthcare Research and Quality National Readmission Database, which included women who experienced childbirth from January 2010 to December 2016.

Patients (N = 26,469,771, mean [SD] age 28.1 [6.0] years) were required to have been admitted for childbirth, have 2 months of follow-up data, and not receive a diagnostic lumbar puncture (n = 22,130,815 patients who met the inclusion criteria).

Post-dural puncture headache within 2 months of childbirth was considered to be the primary exposure, and included either a reaction to spinal or lumbar puncture; a spinal and epidural anesthesia-induced headache during labor and delivery; or an epidural anesthesia-induced headache during the immediate postpartum period.

The primary outcome was the incidence of subdural hematoma, while secondary outcomes were in-hospital mortality and the occurrence of neurosurgery.

Blood Patch Timing Important

Post-dural puncture headaches were identified in 68,374 deliveries, representing an overall rate of 309 (95% confidence interval [CI], 302 - 316) per 100,000 women.

Postpartum subdural hematoma (n = 342) represented an incidence of 1.5 (95% CI, 1.3 - 1.8) per 100,000 deliveries.

Of these, 25% (95% CI, 18% - 33%) and 75% (95% CI, 67% - 82%) were diagnosed during the birth admission and readmission, respectively.

Women with subdural hematoma were more likely to experience in-hospital mortality, compared with those without (2.9% vs .05%, representing a difference of 2.89%; 95% CI, 0.32% - 5.47%; P = .02).

Of those with subdural hematoma, 21.9% underwent neurosurgery compared to .003% of patients who had not experienced subdural hematoma (difference, 21.9% [95% CI, 14.1% - 30.0%]; P < .001).

The crude absolute increase was calculated as 145 (95% CI, 117 – 174) cases per 100,000 population.

When the researchers adjusted for an array of potential confounders (eg, age, comorbidities, vaginal vs cesarean delivery, hypertension, and preeclampsia), they found that post-dural puncture headache had an odds ratio (OR) for subdural hematoma of 199 (95% CI, 126 - 317; P < .001) and an adjusted absolute risk increase of 130 (95% CI, 90 - 169; P < .001) per 100,000 deliveries.

Coagulopathy, arteriovenous malformation, and delayed blood patch were found to have the highest level of association with subdural hematoma (adjusted ORs of 3.35 [95% CI, 1.55 - 7.22); 32 [95% CI, 5 - 215]; and 39 [95% CI, 14 - 108], respectively).

On the other hand, obesity and cesarean delivery without labor had negative adjusted absolute risk differences for subdural hematoma (−0.6 [95% CI, −1.3 to 0.0] and −0.6 [95% CI, −1.2 to 0.0] per 100,000 population, respectively).

There were statistically significant interactions between post-dural puncture headache and severe preeclampsia and chronic hypertension (β, −3.154 [SE, 1.123]; P = .005 and β, −1.581 [SE, 0.473]; P < .001, respectively).

Notably, a delayed blood patch was associated with an adjusted OR of 39 (95% CI, 14 - 108; P < .001 and an adjusted risk difference of 4659 (95% CI, 306 - 9011; P < .03) per 100,000.

"When we looked at other risk factors, we found some interesting things," Moore commented.

"Patients with hypertension, either before the pregnancy or pregnancy induced, [and] patients with coagulopathies and preexisting arteriovenous malformations in the brain had higher rates of subdural hematoma."

After adjusting for other risk factors, the researchers found that a blood patch performed at any time following the diagnosis of post-dural puncture headache did not appear to protect against subdural hematoma.

However, when looking specifically at the association with later blood patches — which were defined as "any happening in a readmission after post-dural puncture headache diagnosis" — the researchers found "much higher rates of subdural hematoma, suggesting that earlier blood patches are associated with lower rates of subdural hematoma and delayed blood patches with higher rates," Moore said.

A Major Contribution

Commenting on the findings for Medscape Medical News, Edward Riley, MD, professor of anesthesiology, perioperative and pain medicine at Stanford University School of Medicine in California, described the study as a "major contribution to the field."

"[This study] shows that dural puncture is not benign," Riley said.

Riley, who was not involved with the research, emphasized that there is "no take-home message suggesting that women should avoid epidurals during childbirth or that other individuals should avoid spinal anesthesia, since the benefits still outweigh the risks of these procedures."

He recommended "diligent follow-up and treatment of post-dural puncture headaches, because they are significant."

The authors point out that their study is observational, and therefore can only assess an association between post-dural puncture headache and subdural hematoma.

"Further research is needed to establish if this association is causal for this rare outcome," they write.

The financial costs of the study were paid for by a grant from the McGill University Health Center Department of Anesthesia research fund. Moore and coauthors and Riley have disclosed no relevant financial relationships.

JAMA Neurology. Published online September 16, 2019. Abstract

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