REPEATED DURAL PUNCTURES INCREASE THE INCIDENCE OF POSTDURAL PUNCTUREHEADACHE

Previous studies have failed to find a significant correlation between the number of dural punctures and the incidence of postdural puncture headache (PDPH), questioning the hypothesis that leakage of cerebrosp inal fluid (CSF) through the dural tear is the cause of PDPH. We hypot hesized that insufficient statistical power of these studies was the c ause for this unexpected finding, and reexamined whether repeated dura l punctures increase the incidence of PDPH by analyzing prospectively collected data on 8034 spinal anesthetics. Uneventful spinal anestheti cs, including a single subarachnoid injection of local anesthetics, oc curred in 7865 (97.9%) cases, whereas failed spinal anesthetics requir ing repeated dural puncture for a second subarachnoid injection of loc al anesthetics occurred in 165 (2.1%) cases. The two groups were simil ar with regard to age, sex, and ASA physical status. We found that rep eated dural punctures significantly increased the incidence of PDPH. W e conclude that increased risk of PDPH is a disadvantage of performing a second subarachnoid injection of local anesthetics after a failed s pinal anesthetic. Moreover, this result suggests that leakage of CSF t hrough the dural tear is the most plausible cause of PDPH.