Anesthesiology
-
The effects of epidural needle design, angle, and bevel orientation on cerebrospinal fluid leak after puncture have not been reported. The impact of these factors on leak rate was examined using a dural sac model. Dural trauma was examined using scanning electron microscopy. ⋯ Cerebrospinal fluid leak after puncture was influenced most by epidural needle gauge. Leak rate was significantly less for the 20-gauge Tuohy needle.
-
The mechanisms responsible for initiation of persistent neuropathic pain after peripheral nerve injury are unclear. One hypothesis is that injury discharge and early ectopic discharges in injured nerves produce activity-dependent irreversible changes in the central nervous system. The aim of this study was to determine whether blockade of peripheral discharge by blocking nerve conduction before and 1 week after nerve injury could prevent the development and persistence of neuropathic pain-like behavior in the spared nerve injury model. ⋯ Peripheral long-term nerve blockade has no detectable effect on the development of allodynia or hyperalgesia in the spared nerve injury model. It is unlikely that injury discharge at the time of nerve damage or the early onset of ectopic discharges arising from the injury site contributes significantly to the persistence of stimulus-evoked neuropathic pain in this model.