Regression of sensory and motor blockade, and analgesia during continuous epidural infusion of ropivacaine and fentanyl in comparison with other local anesthetics.

OBJECTIVE: To compare the regression of sensory and motor blockade, and the analgesia during continuous epidural infusion between ropivacaine and other local anesthetics. DESIGN: Two studies were conducted. Study 1: Eighty patients were scheduled for orthopedic procedures of the lower extremity under lumbar epidural anesthesia. Following the operation, continuous infusion of a randomized solution (0.2% ropivacaine, 0.125% bupivacaine, 0.5% lidocaine, or 0.2% ropivacaine with 2.5 microg/mL fentanyl) was commenced at a rate of 6 mL/h. The regression of sensory and motor blockade were compared among the groups. Study 2: After gynecologic abdominal surgery, 39 patients were randomized to one of the three epidural infusion groups: 0.2% ropivacaine, 0.125% bupivacaine, or 0.2% ropivacaine with 2.5 microg/mL fentanyl at a rate of 6 mL/h with an additional bolus injection of 3 mL, which can be used when patients have pain. Visual analog scale (VAS) was compared among the groups. RESULTS: Study 1: The level of sensory blockade in all the groups appeared to decrease progressively. However, the regression of sensory blockade was significantly prolonged in patients treated with ropivacaine. The addition of fentanyl to ropivacaine augmented this prolonged analgesic effect. Study 2: VAS after the bolus in the ropivacaine and the ropivacaine + fentanyl groups were significantly lower than that in the bupivacaine group. Patients in the ropivacaine + fentanyl group required significantly fewer supplemental bolus injections. CONCLUSIONS: Continuous epidural infusion of ropivacaine may induce a slower regression of sensory blockade compared with bupivacaine and lidocaine. The addition of fentanyl to ropivacaine can enhance this prolonged analgesic effect with little effect on motor blockade. Epidural infusion of ropivacaine with fentanyl provides effective pain relief, possibly because of the maintenance of sensory blockade by ropivacaine and fentanyl.

Effectiveness of prostaglandin E1 for the treatment of patients with neuropathic pain following herpes zoster.

OBJECTIVE: Postherpetic neuralgia (PHN) is one of the most painful neuropathic conditions, the mechanism of which remains unclear. There is no universally accepted treatment. The pain in PHN is often relieved by bathing, heating, or sympathetic blockade, suggesting a circulation-dependent property of the pain. Therefore, we examined the effectiveness of prostaglandin E(1) (PGE(1)), which has an analgesic effect via improvement of peripheral blood circulation, for patients with PHN. DESIGN: A total of 27 patients with PHN underwent intravenous administration of 60 microg of PGE(1) dissolved in 100 mL of physiological saline and 5 mL of 8.4% sodium bicarbonate solution at an infusion rate of 0.02 microg/kg/min. Oral administration of PGE(1), limaprost alfadex, was followed at doses of 30 microg/day for 2 weeks. Pain at rest and tactile allodynia before and after the treatment was evaluated with visual analog scale (VAS). RESULTS: Intravenous PGE(1) significantly decreased VAS in rest pain and tactile allodynia without severe adverse effects. The analgesic effect of PGE(1) continued during the 2 weeks of oral administration of PGE(1). Oral PGE(1) caused nausea in seven cases, diarrhea in three, and abdominal distention in one subject. All subjects, except for two cases of nausea, continued the treatment until the end of the study, although some required a decrease in the dose to 15 microg/day. During the 2-week oral administration, the VAS did not change remarkably in the three patients whose VAS were not decreased by at least 80% during the initial infusion. CONCLUSIONS: The results of the present study indicate that oral PGE(1) following the intravenous administration produces prompt and continuous analgesia in patients with PHN. Moreover, the intravenous treatment using PGE(1) appears useful for predicting the analgesic effect of PGE(1) in the patients.

Sumatriptan alleviates pain in patients with trigeminal neuralgia.

OBJECTIVES: Arterial compression of the trigeminal root may lead to trigeminal neuralgia. 5-HT1B/1D receptor agonists may inhibit vasodilation and inflammation near the irritated trigeminal root. A recent study showed attenuation of mechanical allodynia by a 5-HT1A receptor agonist in a rat model of trigeminal neuralgia. The present study examined the effectiveness of a 5-HT1A/1B/1D receptor agonist, sumatriptan, on pain relief in patients with trigeminal neuralgia. METHODS: The study was conducted in 15 patients with idiopathic trigeminal neuralgia. The patients had been suffering from painful paroxysms for at least 1 month. Each patient was injected with 1 mL of saline subcutaneously (placebo), followed 15 minutes later with subcutaneous sumatriptan (3 mg in 1 mL saline). This was followed the next day by oral sumatriptan (50 mg twice daily) for 1 week. RESULTS: The visual analog scale did not change after saline, but significantly decreased after subcutaneous sumatriptan. Both 1 week after oral sumatriptan and 1 week after discontinuation of the drug, visual analog scale scores resulted in a significant decrease from the baseline. Adverse events after subcutaneous sumatriptan occurred in 4 patients: fatigue in 4 and nausea in 2. Side effects from the oral medication appeared in 4 patients: fatigue in 2, nausea in 1 and chest discomfort in 1. These side effects subsided soon after discontinuation of sumatriptan. CONCLUSIONS: Our results indicate that subcutaneous injection followed by oral administration of sumatriptan produces prompt and continuous analgesia in patients with trigeminal neuralgia.

[Effectiveness of ropivacaine and fentanyl for postoperative epidural analgesia following thoracic surgery].

BACKGROUND: Epidural ropivacaine is now a common drug used for postoperative analgesia. However, little information is available concerning regression of sensory blockade and analgesia following prolonged epidural infusion of ropivacaine. We investigated the efficacy of ropivacaine and fentanyl for postoperative analgesia after thoracic surgery. METHODS: Thirty patients undergoing thoracic surgery were enrolled. After surgery with general and thoracic epidural anesthesia, continuous epidural infusion of 0.2% ropivacaine+fentanyl (1.67 microg x ml(-1)) was started at a rate of 6 ml x h(-1) for patients whose height was more than 155 cm and 4 ml x h(-1) for those below 155 cm with possibility of an additional bolus injection of 3 ml at least every 60 min. RESULTS: An additional epidural injection of 3 ml produced a decrease in VAS without significant changes of vital signs. The greatest VAS was 10+/-25 mm in the incision site and 36+/-38 mm in the ipsilateral shoulder. Sensory blockade was sustained until the morning after the day of surgery. Also blood pressure and heart rate were stable throughout the observation period. There were no adverse effects except for slight nausea in three patients. CONCLUSIONS: A bolus of 3 ml with continuous 4-6 ml x h(-1) epidural injection of ropivacaine plus a small dose of fentanyl would decrease postoperative pain with stable vital signs in patients after thoracic surgery.