Epidural pressure and postdural puncture headache in the parturient

Forty patients in whom the dura had been punctured accidentally and 10 patients who had received spinal anaesthesia required epidural blood patching for relief of severe postdural puncture headache (PDPH). Before injecting blood, the epidural pressure was measured, using an epidural catheter as a manometer. Mean epidural pressure in the left lateral position was 6.4 cm H(2)O (range 0.5-12 cm H(2)O). Epidural pressure was not related to the size of needle hole or prophylactic infusion of saline into the epidural space. In 5 patients with inadvertent dural tap, there was a statistically significant decrease (P<0.02) in epidural pressure from 14.9 cm H(2)O (range 11-22 cm H(2)O) before PDPH to 6.9 cm H(2)O (range 5-8.5 cm H(2)O) when they developed PDPH. The benefits of performing an epidural blood patch through a catheter placed in the epidural space are discussed.