15: Postdural Puncture Headache

INTRODUCTION

Postdural puncture headache (PDPH) continues to be one of the most common complications of neuraxial anesthesia used in obstetrics. It is critical that the obstetric anesthesiologist be able to recognize the difference between PDPH, the incidence of which may approach 40%, and other causes of postpartum headache.¹ PDPH is also the third most common cause of litigation stemming from neuraxial anesthesia.² In fact, claims related to maternal death and newborn death/brain damage have steadily decreased since 1990, but PDPH settlements have seen a steady increase.³ Retrospective analysis indicates that the most frequently cited reason for a patient’s deciding to pursue legal action was a lack of full disclosure regarding potential for PDPH and/or lack of follow-up by the anesthesiologist.² Although the headache itself is the usual official complaint, it seems that poor communication and an absence of empathy is what actually drives the majority of these legal actions. Accordingly, patients should be counseled about the risks of PDPH prior to every neuraxial anesthetic. If a Tuohy needle accidentally punctures the dura, it is imperative that, after the patient is comfortable, the potential risk of headache be once again explained. At that time, the patient should be advised of specific treatment options and reassured that adequate follow-up will be available.

WHAT CAUSES A POSTDURAL HEADACHE?

The symptoms of PDPH are thought to be due to leakage of cerebrospinal fluid (CSF) through a dural defect produced by the dural puncture. If the rate of CSF leakage exceeds the rate of production of CSF (approximately 550-700 mL/d, with 120-150 mL present in the subarachnoid space at any given time), then on assuming an upright position, the downward traction on the pain-sensitive intracranial veins, meninges, and cranial nerves results in headache. Other contributing factors to patient discomfort may be related to a compensatory vasodilation to account for loss of intracranial CSF volume as the body attempts to achieve homeostasis by maintaining a constant intracranial volume.⁴

HOW OFTEN DOES A POSTDURAL HEADACHE OCCUR AND WHO GETS IT?

It is important to remember that PDPH may arise either from an intentional dural puncture for a spinal anesthetic or an unintended dural puncture from the placement of an epidural needle. The overall incidence of unintentional dural puncture during attempted epidural placement lies somewhere in the range of 0.5% to 2.0%, depending on the experience of the clinician and characteristics of the patient.⁵ Whether the patient actually develops a headache is dependent on a number of variables. The landmark study by Vandam et al. identified three independent risk factors for developing a headache after unintended dural puncture in the general population. Female, younger, and pregnant patients were more likely than male, older, and nonpregnant patients to develop headache after dural puncture with identical needles.⁶

The needle gauge is the other major determinant for ...