Postdural Puncture Headache (PDPHA), as defined by the International Headache Society, is any headache that develops within 5 days of dural puncture and is not better explained by another cause. While the classic symptoms of PDPHA highlight a positional component that worsens with sitting or standing and improves with lying flat, a small minority of patients have the opposite symptomatology. The headache is usually frontal or occipital in nature, and sometimes associated with neck stiffness, auditory symptoms, visual disturbances, and nausea. Most present within the first 48 hours, though a quarter of cases may occur 3 days following dural puncture. Symptoms are believed to be due to leakage of CSF from the dural tear, which creates traction on the brain and cranial nerves.
Commonly associated with the obstetric population, PDPHA is, however, not the leading cause of headache in these patients. More common are tension headaches and preeclampsia. The established incidence of PDPHA is around 1%, based on findings from the SCORE project which studied both spinal anesthetics and accidental dural puncture during epidural anesthesia. Risk factors for PDPHA include young age and female gender. Obesity may be protective, and cesarean section is definitely more protective than vaginal delivery among parturients. The latter is theorized to be due to a lack of straining during the second stage of labor, which may worsen CSF leakage.
Most PDPHA resolve spontaneously within 2 weeks, but several studies have shown that in a small subset of patients, symptoms may persist for more than 6 weeks. Therefore, prompt follow-up and treatment of PDPHA is recommended.
While there is no proven method of prevention, some anesthesia providers place prophylactic epidural blood patches after suspected dural puncture during epidural placement. Standardized trials of this technique have shown mixed results. Others advocate for threading intrathecal catheters in the event of a known accidental dural puncture, theorizing that the catheter will hinder the escape of CSF and create a fibrotic process that helps seal the dural tear. While some studies have drawn some promising conclusions with this method, the results have again been inconsistent in practice.
Treatment of PDPHA has historically included intravenous caffeine, despite no studies subsequent to the initial publication supporting its efficacy. Emergency medicine case series advocate for sphenopalatine ganglion blocks, performed using a lidocaine-soaked cotton-tip swab inserted in the nostril; however, this is not routinely used. The mainstay of treatment and the only method borne out in studies to be effective for PDPHA is the epidural blood patch. 20ml has been shown to be the optimal volume of sterile blood injected into the epidural space, stopping sooner if the patient experiences back pain. Serious complications, while rare, include radicular pain from nerve root compression, chronic adhesive arachnoiditis, and epidural hematoma. Failed blood patch requiring a repeat procedure occurs roughly 10% of the time.
Given that PDPHA is a leading cause of litigation despite being a well-described and relatively straightforward to manage problem, it is important for anesthesia providers to be aware of identifying and managing this condition.
References:
Gaiser RR. Postdural puncture headache: a headache for the patient and a headache for the anesthesiologist. Curr Opin Anaesthesiol. 2013 Jun;26(3):296-303.