Comparison between Epidural Analgesia and Combined Spinal-Epidural Analgesia for Labor and Delivery / 대한마취과학회지

BACKGROUND: This study was designed to compare analgesic efficacy and side effects of intrathecal morphine and fentanyl with epidural bupivacaine. METHODS: Twenty nine healthy women, ASA physical status 1 or 2 with an uncomplicated pregnancy and single fetus in vertex position were given lumbar epidural or combined spinal-epidural analgesia. In the epidural analgesia group (n = 18), 0.25% bupivacaine 8 - 10 ml and fentanyl 50 - 75ng was injected into the epidural space. In the CSE group (n = 11), analgesia performed dural puncture with a 27 gauge spinal needle and fentanyl 15ng and morphine 0.2 mg in 2 ml normal saline solution was injected. In both groups, whenever the patient requests further analgesia, we injected 0.125% bupivacaine 10 ml and fentanyl 50 - 75ng into the epidural space. RESULTS: There was no significant difference between the two groups in duration of analgesia, the second stage of labor and pushing. The CSE group offers rapid onset time. The total dose of bupivacaine and fentanyl administered during analgesia was significantly more in the epidural group than the CSE group. After intrathecal fentanyl 15ng and morphine 0.2 mg, the duration of analgesia was 162 +/- 122 min. After the first 0.25% bupivacaine 10 ml and fentanyl 50 - 75ng, it was 92.5 +/- 5 min in the epidural group and 190 +/- 101 min in the CSE group (P < 0.05). CONCLUSIONS: Compared with epidural analgesia, Intrathecal fentanyl 15ng and morphine 0.2 mg as part of CSE analgesia provide rapid onset time and prolonged analgesia, and a lower total dose of local anesthetics for labor and delivery. However women who received CSE analgesia were more likely to itch (64%) than solely epidural analgesia.

Effects of Capsaicin on the Primary Sensory Neurons in Rat / 대한마취과학회지

BACKGREOUND: Capsaicin acts specifically on a subset of primary sensory neurons involved in nociception. In addition to its excitatory actions, capsaicin can have subsequent antinociception and anti-inflammatory effects due to pharmacological, functional desensitization and axonal degeneration. Because capsaicin has selective actions on unmyelinated C and thinly myelinated Adelta primary sensory neurons, it can be speculated that intrathecally adminstered capsaicin results prolonged analgesia without adverse effects related to the destruction of the nonnociceptive nerve fibers. METHODS: We performed experiments to investigate the effects of capsaicin on electrophysiological responses of acutely dissociated rat dorsal root ganglion neurons and pain-like behaviors, such as tail flick responses to hot water (53 degrees), formalin-induced hyperalgesic responses and allodynic responses induced by peripheral nerve injury. RESULTS: Capsaicin affects preferentially small- to medium-diameter rat dorsal root ganglion neurons. In capsaicin responsive cells, superfusion with capsaicin evoked membrane potential depolarization and large inward currents. Cellular excitablity was continuously suppressed even after 3 min wash-out. Intrathecally administered capsaicin had no effect on tail withdrawal latencies, but flinching responses induced by subcutaneous formalin and allodynic responses induced by peripheral nerve injury were suppressed by capsaicin. CONCLUSIONS: The results suggest that capsaicin which acts on primary sensory neurons carrying nociceptive information is effective in managing pain induced in a pathological condition, such as inflammatory and neuropathic pain. The data may also be applicable for seeking novel pharmacological strategies for managing intractable pain, i.e. chemical neurolysis.