The Antiallodynic Effect and the Change of the alpha2 Adrenergic Receptor Subtype mRNA Expression by Morphine Administration in a Spinal Nerve Ligation Rat Model

BACKGROUND: The neuropathic pain arising from nerve injury is difficult to treat and the therapeutic effects of opioid drugs remain debatable. Agonists acting at the alpha2 adrenergic and opioid receptors have analgesic properties and they act synergistically when co-administered in the spinal cord. The lack of subtype-selective pharmacological agents has previously impeded the synergistic effects that are mediated by the adrenergic receptor subtypes. METHODS: We created neuropathic pain model by ligating the L5 spinal nerve in Sprague-Dawley rats (n = 18). We divided the rats into three groups (n = 6 for each group), and we administered intraperitoneal morphine (1 mg/kg, 3 mg/kg, 5 mg/kg) and then we measured the mechanical allodynia with using von-Frey filaments for 8 hours. We then injected morphine (5 mg/kg) intraperitoneally, twice a day for 2 weeks. We measured the tactile and cold allodynia in the morphine group (n = 9) and the saline group (n = 9). After 2 weeks, we decapitated the rats and harvested the spinal cords at the level of lumbar enlargement. We compared the alpha2 subtype mRNA expression with that of control group (n = 6) by performing real time polymerase chain reaction (RTPCR). RESULTS: Intraperitoneal morphine reduced the neuropathic pain behavior in the dose-dependent manner. Chronic morphine administration showed an antiallodynic effect on the neuropathic pain rat model. The rats did not display tolerance or hyperalgesia. The expression of the mRNAs of the alpha2A, alpha2B, alpha2C subtypes decreased, and morphine attenuated this effect. But we could not get statistically proven results. CONCLUSIONS: Systemic administration of morphine can attenuate allodynia during both the short-term and long-term time course. Morphine has an influence on the expression of alpha2 receptor subtype mRNA. Yet we need more research to determine the precise effect of morphine on the alpha2 subtype gene expression.

Relationship between carotid intima-media thickness and hemodynamic changes during anesthetic induction / 대한마취과학회지

BACKGROUND: The carotid intima-media thickness (IMT) have been known to be related to the degree of atherosclerosis and cardiovascular risk factors. The aim of this study was to elucidate the relationship of IMT and the hemodynamic changes during anesthetic induction. METHODS: Two hundred fourteen patients scheduled for general anesthesia were studied. The blood pressures and heart rates during anesthetic induction and endotracheal intubation were measured. IMT was measured at right common carotid artery using M-mode ultrasonography after anesthesia, RESULTS: Mean IMT of the patients was 0.611 +/- 0.146 (0.34-0.96) mm. IMT was significantly related with age, systolic blood pressure, the changes of blood pressure after induction, and the changes of blood pressure after intubation. IMT was not related for basal heart rate and the changes of heart rate during anesthetic induction and intubation. CONCLUSIONS: IMT is related with the magnitude of blood pressure decreasing during anesthetic induction and increasing during intubation. The further study is needed to evaluate the relationship of IMT and hemodynamic changes during other anesthetic practice.

Intraoperative awareness during sevoflurane-remifentanil anesthesia for minimal invasive mitral valvuloplasty: A case report / 대한마취과학회지

We report a case of unintentional intraoperative awareness during sevoflurane-remifentanil anesthesia in a 26 years old woman undergoing elective minimal invasive mitral valvuloplasty. Cardioprotective effects of sevoflurane were clinically most apparent when administered throughout the surgical procedure. Also use of sevoflurane during cardiopulmonary bypass decreases incidence of awareness. Although awareness during cardiac anesthesia has been previously described with sevoflurane, the implication of this case is that unexpected awareness can occur in patients with sevoflurane during cardiopulmonary bypass on cardiac surgery. Therefore, more attention is needed to use sevoflurane during cardiopulmonary bypass.