[Case of spinal epidural abscess after continuous epidural block to manage the pain of herpes zoster].

A woman in her 90's received continuous epidural block for the pain of herpes zoster. Four days after epidural catheterization, she was found with cellutitis. Fourteen days after epidural catheterization, spinal epidural abscess was pointed out on MRI. Since there were no neurological symptoms, we performed conservative medical management with antibiotics. She recovered without sequela When the symptoms of cellutitis appeared after epidural block (even if there are neither neurological symptoms nor infectious signs), there is a possibility of progressing into spinal epidural abscess.

Gabapentin augments the antihyperalgesic effects of diclofenac sodium through spinal action in a rat postoperative pain model.

BACKGROUND: Gabapentin and nonsteroidal antiinflammatory drugs (NSAIDs) attenuate postoperative pain and neuropathic pain in humans. The combination of gabapentin and NSAIDs is effective for postoperative pain and enhances functional recovery after surgery. Intrathecal administration of gabapentin or NSAIDs inhibits hyperalgesia in a rat postoperative pain model. However, there is no information on the effects of intrathecal administration of a combination of gabapentin and NSAIDs. We therefore investigated the effects of intrathecal administration of gabapentin and NSAIDs in a rat model of postoperative pain. METHODS: Rats were prepared for intrathecal catheters under halothane anesthesia. Two days after catheterization, gabapentin (4, 40, or 400 µg per 20 µL of saline), diclofenac sodium, a nonselective cyclooxygenase inhibitor (2, 20, or 200 µg per 20 µL of 6% glucose), 20 µL saline, 20 µL 6% glucose, and a combination of gabapentin and diclofenac (40 µg gabapentin + 20 µg diclofenac and 4 µg gabapentin + 2 µg diclofenac per 20 µL 6% glucose) were injected intrathecally. We performed a hindpaw incision 30 minutes after injection. Each group consisted of 6 rats. The mechanical threshold was measured to evaluate secondary hyperalgesia using von Frey filaments before intrathecal catheterization and at 2 hours, and 1, 3, 5, and 7 days after paw incision. RESULTS: Gabapentin 400 µg attenuated mechanical hyperalgesia for 7 days compared with the control group. Diclofenac 200 µg inhibited hyperalgesia for 5 days compared with the control group. The 40 µg gabapentin + 20 µg diclofenac group had a significantly reduced secondary hyperalgesic response in 2 hours and 1 day compared with 40 µg gabapentin and 20 µg diclofenac, respectively. The 4 µg gabapentin + 2 µg diclofenac group had a significantly reduced secondary hyperalgesic response in 2 hours and 1 day compared with 2 µg diclofenac. The withdrawal threshold on the contralateral paw did not change compared with the preincision threshold. CONCLUSION: Intrathecal administration of gabapentin and diclofenac in combination reduced secondary hyperalgesia at doses having no antihyperalgesic effects when given individually. Our results suggest that gabapentin and diclofenac have an important role in postoperative pain reduction at the spinal level, and that gabapentin augments the antihyperalgesic effects of diclofenac through action in the spinal cord.