Unintentional dural puncture in the obstetric patient is a complication. In an Obstetric Anesthesiology closed-claim study published in the American Society of Anesthesiologists newsletter in 1999, PDPH was the third most common reason for claim (15% of obstetric claims). Such headaches are more common than nerve damage, pain during anesthesia, and maternal brain damage. The median duration of untreated PDPH is 5 days, with a range of 1 to 12 days.

Note that other complications may result from neuraxial anesthesia for obstetrics, and always consider the possibility of concomitant complications. Some of the other complications of epidurals include epidural catheter complications, unintentional subarachnoid injection, intravascular injection of
local anesthetic, direct spinal cord injury, bloody tap, epidural abscess, local anesthetic toxicity, and epidural hematoma.

Two proposed pathophysiologic mechanisms for PDPH are (a) continued leak of cerebrospinal fluid (CSF) leads to loss of brain support and results in traction on the meninges of the brain, which are pain-sensitive structures; and (b) loss of CSF results in intracranial hypotension, causing compensatory cerebral vasodilatation and dilatation of intracerebral veins, which, in turn, results in a downward sagging of the brain and subsequent tension on the meninges. Activation of adenosine receptors is another, less widely accepted, postulated mechanism.

Significant risk factors include age, gender, needle diameter, needletip design, orientation of the tip during puncture, previous PDPH, history of migraine, and repeated attempts to achieve puncture. Younger patients are more prone to PDPH. Premenopausal women are twice as likely as men to have PDPH. The risk for PDPH relates directly to the diameter of the needle used. The smaller the gauge of the needle used, the lower the incidence of PDPH is. Needle-tip design is also important. Pencil-point needles (Sprotte, Whitacre) have a side orifice on the needle and result in a lower incidence of PDPH than do those with a cutting-point (Quincke). Needle-bevel orientation during insertion is also important. The frequency nearly doubles when the bevel of the needle is inserted perpendicularly instead of parallel to the longitudinal dura fibers. Lastly, the more attempts that are made at a neuraxial technique, the greater the risk for PDPH is, and patients with a history of migraine headaches and previous PDPH are more prone to PDPH.

Most anesthesiologists recommend removing the needle and placing the epidural in a new interspace, either above or below the previous attempt. Some anesthesiologists recommend placing an intrathecal catheter and using this for obstetrical anesthesia.

Historically, conservative treatment modalities for PDPH were bed rest; hydration; lying in a prone position; abdominal binders; caffeine, oral, or intravenous; theophylline; serotonin agonists; and corticosteroids.

Continued bed rest and lying in the prone position often result in a “trend toward increased headache.” Allowing early ambulation does not increase the risk for PDPH; on the contrary, early ambulation is recommended.
Additional hydration does not decrease incidence of PDPH. Anecdotal evidence for abdominal binders has been theorized to work by increasing intra-abdominal pressure, thereby equalizing CSF compartment pressures with epidural space pressures. Caffeine (500 mg, intravenously) resolved the symptoms in over two thirds of subjects tested in one trial. Oral dosing of 300 mg of caffeine resulted in only brief relief of symptoms in most patients. A single study using oral theophylline was done, but benefits have not been confirmed, and most anesthesiologists would say the risks outweigh the possible benefits. Trials of serotonin agonists have been done but have not had reproducible results. Lastly, there is only anecdotal evidence for use of corticosteroids.