Post-Dural Puncture Headache

As previously mentioned, PDPH will develop in up to 70% of patients after accidental dural puncture. However, not all postpartum headaches occur as a result of dural puncture. A large analysis reported that headaches occurred in 15% of parturients who did not receive an epidural and in 12% of parturients who had an epidural but did not show evidence of dural puncture.^[204] Other causes of headache in the postpartum period include nonspecific headache, migraine, hypertension, pneumocephalus, infection including sinusitis and meningitis, cortical vein thrombosis, and intracerebral pathology. In addition, because coffee and tea intake is so prevalent, one should also consider caffeine withdrawal in the differential diagnosis. PDPH has the typical features of a postural headache that is worsened by standing or straining and relieved by lying down.

Generally, PDPH is initially treated conservatively with increased intake of both oral and intravenous caffeine and analgesics. No evidence, however, has shown that increasing fluid intake will cause a greater production of CSF; recently, the use of intravenous fluid has been questioned.

Drugs that have been used to treat PDPH include caffeine, vasopressin, theophylline, sumatriptan, and adrenocorticotropic hormone (ACTH). Caffeine, a cerebral vasoconstrictor, has been used successfully, but the effects appear to be transient. ^[205] Caffeine treatment seems to be more effective when headaches are the result of smaller rather than larger needles. A negative aspect of caffeine treatment is that patients may feel anxious and unable to sleep. In addition, seizures and cardiac arrhythmias have been reported after caffeine administration.^[206] Although some of the caffeine is present in breast milk, deleterious effects on the newborn have not been shown. ^[207] One recent study suggested that intravenous administration of caffeine may be effective for prophylaxis of PDPH.^[208] Theophylline, which is also a cerebral vasoconstrictor and is available in long-acting formulations, may be useful in the pharmacologic treatment of PDPH. Unfortunately, the only study to evaluate this drug for PDPH has been published solely in abstract form.^[209] Sumatriptan, a serotonin agonist with cerebral vasoconstriction properties that is routinely used to treat migraine headaches, has also been used in the treatment of PDPH.^[210] ACTH has likewise been anecdotally reported as a treatment of PDPH.^[211]

If the symptoms are severe enough to limit a mother's activity or if evidence of cranial nerve involvement is noted, an epidural blood patch may be performed. The epidural blood patch was first described more than 40 years ago, and it continues to be the most effective treatment of PDPH. Although early reports suggested immediate and permanent cure of PDPH, it has recently been suggested that complete success rates are approximately 75% and that the effectiveness of an epidural blood patch is decreased if the dural puncture is caused by a large-bore needle. ^[212] One study reported that although immediate relief occurred in almost all patients, permanent cure after an epidural blood patch was achieved in only 61%.^[213] The success of an epidural blood patch is probably not as simple as the clotted blood obstructing the dural tear. CSF volume replacement is not rapid, yet the symptoms resolve almost immediately. Other explanations for the effectiveness of an epidural blood patch include an increase in CSF pressure and cerebral vasoconstriction.^[214] Some controversy has arisen regarding the optimal volume of blood to be injected; however, most practitioners use 15 to 25 mL and stop injection of the blood if severe pain occurs. Although the incidence of complications (especially back pain) increases with increased volume, it appears that increased volume also increases the success rate.^[215]

Radiologic studies using radiopaque dye while performing the blood patch have shown that blood inserted into the epidural space will travel one space below the level of insertion of the epidural needle and up to four spaces above the site.^[216]