We describe a new method for radio-frequency mandibular nerve rhizotomy under CT fluoroscopy. A patient with cancer had severe intractable and drug-resistant pain in his left mandibular region. ...Because he had an anatomic deformity due to cancer invasion and radiation therapy, we planned a mandibular nerve rhizotomy under CT fluoroscopic imaging. The needle was advanced to the mandibular nerve just caudal to the foramen ovale under real-time CT fluoroscopy, avoiding the cancer region. Pain scores of the patient were reduced after the nerve rhizotomy, without any complications.
We have applied compressive stress perpendicular to YBCO coated tapes, and measured the degradation of critical currents. When the tape was pushed from the silver surface of the tape, the performance ...of the tape hardly decreases. On the other hand, compressing from the hastelloy face, degradation of the tape occurred. We observed the damage of the tapes by a magneto-optical imaging technique. The observed results were consistent with the degradation data. From those results, we think that it is better not to compress strongly from the hastelloy side.
The purpose of this study was to evaluate the effect of ephedrine and phenylephrine on propofol concentrations and bispectral index during propofol anesthesia.
General anaesthesia was induced with ...propofol and was maintained with propofol (4 mg kg-1 h-1) and fentanyl. Vecuronium was used to facilitate the artificial ventilation of the lungs. Patients with systolic blood pressure > 90 mmHg were defined as the control group (n = 16). Patients who had to be treated for larger decreases in arterial blood pressure (systolic blood pressure 60, whereas no patient in the control or phenylephrine groups had bispectral index >60. There were no significant differences in propofol concentrations or cardiac output relative to baseline at 3 or 10 min after the administration of ephedrine or phenylephrine.
Ephedrine increases bispectral index values without decreasing propofol concentrations during general anesthesia.
Adrenomedullin is a potent vasodilatory peptide. The mechanisms of adrenomedullin-induced responses are via guanine nucleotide guanosine 5'-triphosphate-binding protein (G-protein)-coupled receptor ...activation and are similar to those of calcitonin gene-related peptide (CGRP). Previously, we reported that sevoflurane and isoflurane inhibit CGRP-induced haemodynamic responses. The effects of volatile anaesthetics on adrenomedullin-induced haemodynamic responses, however, are unclear. We hypothesized that the volatile anaesthetic isoflurane inhibits adrenomedullin-induced haemodynamic responses. We studied the effects of isoflurane on adrenomedullin-induced haemodynamic responses in pithed rats, which enables us to evaluate the direct cardiovascular effects of drugs without interference from centrally mediated circulatory reflexes.
Male Wistar rats were pithed by inserting a stainless-steel rod into the spinal cord. Following median sternotomy, a flow probe was placed around the ascending aorta to measure aortic blood flow. Mean arterial pressure and cardiac output were maintained at approximately 100 mmHg and 50 mL min-1, respectively, with continuous infusion of norepinephrine. After 30 min inhalation of isoflurane (1%, or 2%) in oxygen, or only oxygen, adrenomedullin (1, 3, 10 or 30 microg kg-1) was administered intravenously.
Adrenomedullin administration induced a transient increase followed by a persistent decrease in mean arterial pressure and cardiac output. Isoflurane (2%) significantly inhibited the initial increase in mean arterial pressure and the later decrease in mean arterial pressure and systemic vascular resistance.
Isoflurane inhibits adrenomedullin-induced vasodilation and positive inotropic effect in pithed rats. Isoflurane might inhibit the adrenomedullin receptor-mediated response, which is a common pathway for both actions.
Antidepressants are often used to treat neuropathic pain. In the present study, we determined the antiallodynic effects of selective monoamine reuptake inhibitors in the spinal cord in a rat model of ...neuropathic pain. Mechanical allodynia was produced by tight ligation of the left L5 and L6 spinal nerves and determined by applying von Frey filaments to the left hindpaw. A serotonin noradrenaline reuptake inhibitor, milnacipran, a selective serotonin reuptake inhibitor, paroxetine, or a selective noradrenaline reuptake inhibitor, maprotiline, was administered intrathecally via a chronically implanted catheter. Milnacipran produced dose-dependent antiallodynic effects at doses between 3 microg and 100 microg. The effect lasted for 7 h after injection of 100 microg (P < 0.05). The antiallodynic effect of 30 microg of milnacipran was attenuated by intrathecal coadministration of 30 microg of yohimbine, an alpha(2)-adrenoceptor antagonist, 30 microg of methysergide, a serotonin receptor antagonist, or 30 microg of atropine, a muscarinic receptor antagonist (P < 0.01, respectively). Intraperitoneal administration of milnacipran had no antiallodynic effects at doses of 3 to 30 mg/kg. Antiallodynic effects were not produced by intrathecal administration of paroxetine (10 to 100 microg) or maprotiline (10 to 100 microg). These findings suggest that simultaneous inhibition of serotonin and noradrenaline reuptake in the spinal cord is essential to mediate antiallodynic effects. Milnacipran might be effective for suppression of neuropathic pain.
Systemic ketamine suppresses several types of chronic pain. Although ketamine is used as a general anesthetic agent, the analgesic effect of systemic ketamine for early-stage postoperative pain is ...not clear. We investigated the efficacy and mechanism of systemic ketamine in a rat model of postoperative pain.
An incision was made in the plantar aspect of the left hind paw in male Wistar rats. Mechanical hypersensitivity was measured using calibrated von Frey filaments. The anti-hypersensitivity effect of systemic or intrathecal administration of ketamine was determined every hour after making the incision. We examined the effects of intrathecal pretreatment with yohimbine, an alpha2-adrenoceptor antagonist, and methysergide, a serotonergic receptor antagonist, on the anti-hypersensitivity effect of ketamine. We also examined the effect of systemic ketamine on the c-fos immunoreactivity in the spinal cord.
Systemic administration of ketamine at doses from 3 to 30 mg.kg(-1) produced anti-hypersensitivity effects in a dose-dependent manner. Intrathecal administration of ketamine had no effect. There was no significant difference between effects of pre- and post-incisional administration. Intrathecal pretreatment with yohimbine (10 microg) or methysergide (15 microg) completely reversed the anti-hypersensitivity effects of systemic ketamine. Systemic ketamine reduced fos expression in laminae I-II in the dorsal horn of the lumbar spinal cord ipsilateral to the paw incision.
The results suggest that systemic administration of ketamine perioperatively suppresses early-stage postoperative pain via monoaminergic descending inhibitory pathways.
The present study was designed to evaluate the efficacy of a cyclooxygenase (COX)-2 inhibitor, etodolac, on postoperative pain after fast-track cardiac surgery, and to examine the changes in plasma ...etodolac concentration after oral administration.
Thirty patients scheduled for elective coronary artery bypass grafting (CABG) surgery were randomly assigned preoperatively in a double-blind fashion to receive either vehicle ( n = 15) or etodolac 400 mg ( n = 15) via a gastric tube at the end of the surgery. Standardized fast-track cardiac anesthesia was used. In both groups, postoperative pain was treated with buprenorphine suppository. Visual analogue pain scores (VASs) were recorded immediately after extubation and at 24 h after surgery. Plasma etodolac concentration was measured at 1, 2, and 6 h after administration ( n = 8).
No difference was detected in time to extubation between the etodolac group (209 +/- 85 min, mean +/- SD) and the vehicle group (207 +/- 98 min). VASs were significantly lower in the etodolac (2.3 +/- 2.1) vs the vehicle group (5.8 +/- 2.0) immediately after extubation ( P = 0.009), but no difference was detected in pain scores at 24 h after surgery, or in the amount of buprenorphine administered in the intensive care unit (ICU), or in the incidence of side effects. Plasma etodolac concentration was within the pharmaceutically recommended range at 1 h, 2 h, and 6 h after administration.
The oral use of etodolac with rectal buprenorphine reduces pain scores immediately after cardiac surgery without an increase in side effects.
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