Management of Postdural Puncture Headache

1.Far from being a minor complication, postdural puncture headache (PDPH) can significantly increase the cost of hospitalization, can have an extremely negative impact on patient satisfaction with a consequent increase in the risk of litigation, and can lead to significant increases in both short-and long-term maternal morbidity.

2.When evaluating patients with presumed PDPH, it is critically important to rule out other potentially life-threatening causes of headache.

3.Numerous pharmacologic treatments for PDPH have been proposed, but there is little evidence to support the routine use of a specific drug.

4.Although evidence supporting the practice is inconclusive, placement of an intrathecal catheter after accidental dural puncture may decrease the risk of developing PDPH.

5.Although not without its own complications, epidural blood patch (EBP) represents the gold standard for treatment of established PDPH. The routine use of prophylactic EBP and the optimal timing of EBP remain controversial.

I. Scope of the problem

Despite advances in neuraxial anesthetic techniques, postdural puncture headache (PDPH) remains a persistent problem. Even in experienced hands, the risk of accidental dural puncture with an epidural needle is approximately 1 in 200, but in many teaching hospitals, the rate is between 1% and 4%. When it occurs, PDPH is often mild in intensity and brief in duration (i.e., 3 to 7 days). However, PDPH is occasionally severe enough to leave patients bedridden and can delay hospital discharge. Symptoms of PDPH have been reported to last months or even years in rare cases.¹ Untreated PDPH can lead to the development of persistent cranial nerve palsies and intracranial hemorrhage.^2,3 Finally, despite a widespread belief among physicians that PDPH is merely a nuisance, it is a frequent and sometimes costly source of litigation.⁴ It is undoubtedly, in the words of Sachs and Smiley,⁵ “the worst common complication in obstetric anesthesia.”

A wide range of conservative and invasive treatments for PDPH has been described in the literature, often with minimal supporting evidence. In this chapter, we review the presumed pathophysiologic mechanisms underlying PDPH as well as the risk factors for PDPH, both those that can be modified and those that cannot. The diagnosis of PDPH is described as well as the other types of headache that are common in the parturient. The rationale for the commonly used methods for preventing and treating PDPH is discussed on the basis of our current understanding of the mechanisms of PDPH. The evidence supporting these techniques will be described when such evidence exists. There are few rigorous, well-controlled studies of the treatment of PDPH, so many of the treatment recommendations will be based on case reports, observational studies, and the author’s experience. More than 100 years after August Bier⁶ first described PDPH, its optimal management is a question that remains unanswered.

II. Pathophysiology

It is well accepted that the proximal cause of PDPH is persistent loss of cerebrospinal fluid (CSF) through a dural, or more accurately, an arachnoid puncture. This leakage leads to headache through one of two presumed mechanisms.

A. Meningeal traction

Continued leak of CSF from a lumbar–dural puncture leads to loss of fluid from the intracranial compartment. The loss of a cushioning effect from CSF allows the brain to sag within the skull, placing traction on the pain-sensitive meninges, an effect that becomes most apparent in the upright position. This suggests that the treatment of PDPH should be based on minimizing CSF leakage, increasing CSF production, or translocating CSF from the spinal to the intracranial compartment.

B. Cerebral vasodilation

The second theory is based on the Monro-Kellie hypothesis, which states that the sum of brain tissue, CSF, and intracranial blood is constant. Thus, a decrease in intracranial CSF will lead to an increase in intracranial blood, mediated through compensatory cerebral vasodilation. This suggests that PDPH is similar to migraine headache, a theory supported by the similarly increased incidence of migraine and PDPH in women, and also by magnetic resonance imaging (MRI) studies that demonstrate enhanced cerebral blood flow in PDPH.⁷ This theory suggests not only that PDPH will be relieved by restoration of intracranial CSF volume but also that cerebral vasoconstrictors might provide symptomatic relief.

III. Risk factors for postdural puncture headache

A. Unmodifiable risk factors

1. Age. Headache is uncommon in elderly patients. The highest risk group appears to be patients younger than 40 years of age, an age range typical for most parturients.

2. Gender. A recent meta-analysis concluded that nonpregnant females are more likely to develop PDPH than males, despite the fact that the women studied were considerably older, a difference which would be expected to decrease the incidence of PDPH in that group.⁸

3. Pregnancy. Pregnant women are more likely to develop PDPH than age-matched, nonpregnant female controls. It has been suggested that it may not be pregnancy per se but rather vaginal delivery (particularly vigorous expulsive efforts in the second stage of labor) that leads to this increased incidence, perhaps due to increased CSF loss. The evidence for this is inconclusive.^9,10

4. Previous postdural puncture headache. A history of prior PDPH is a risk factor for headache after spinal anesthesia.¹¹

CLINICAL PEARLPregnancy and a prior history of PDPH convey greater risk for the development of PDPH.

B. Modifiable risk factors

1. Needle size. Numerous studies show that there is a consistent decrease in the incidence of PDPH as the needle diameter gets smaller. With needles <27 gauge, the increasing technical difficulty of needle placement limits the usefulness of further decreases in diameter.

2. Needle shape. For any needle diameter, the use of conical or “pencil-point” needles (e.g., Whitacre, Sprotte, Gertie Marx) consistently decreases the incidence of PDPH compared to cutting-bevel (e.g., Quincke) needles.¹²

3. Orientation of needle bevel. When a cutting-bevel needle is used, insertion of the needle with the bevel parallel to the longitudinal axis of the body will significantly decrease the risk of headache.¹³

4. Paramedian approach. Although used infrequently in obstetrics, subarachnoid block performed through the paramedian approach appears to significantly decrease the incidence of PDPH.¹⁴

5. Morbid obesity. It has long been thought that the incidence of PDPH is decreased in morbidly obese parturients.¹⁵ A recent study, adds further evidence that obesity provides protection against the development of PDPH.¹⁶

CLINICAL PEARLThe use of small pencil-point spinal needles, with the bevel of a cutting needle oriented parallel to the spinal axis, and a paramedian approach reduces the risk of PDPH.

IV. Diagnosis of postdural puncture headache

A. Occurrence of postdural puncture headache. PDPH may occur immediately after dural puncture or it may not appear for as long as 5 to 7 days. The great majority, however, develop within 48 to 72 hours.

B. Clinical characteristics

1. Posture. The sine qua non of PDPH is exacerbation by upright position and diminution of symptoms with recumbency. Absence of a postural component must cast doubt on the diagnosis of PDPH. The onset of headache may be delayed by as long as 15 minutes after assuming the upright position; however, the absence of a headache immediately after positional change does not rule out PDPH.

2. Location. Typically, headache is distributed in the frontal and occipital regions, with radiation to the neck and shoulders. Pain in the interscapular region of the upper back may be observed.

3. Auditory disturbances. Decreased CSF pressure is transmitted to the cochlea, often producing auditory symptoms such as decreased acuity, tinnitus, and what is often described as a “hollow” sound.

4. Visual disturbances. Diplopia is common, typically due to paresis of lateral gaze due to compression of cranial nerve VI along its long course in the middle fossa by the sagging brain.

CLINICAL PEARLThe onset of headache in a patient with PDPH may be delayed by as much as 15 minutes after assuming the upright position.

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