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Purpose@#The effects of dexmedetomidine on locomotor function and thermal hyperalgesia in sciatic nerve crush injury (SNCI) were investigated using rats. @*Methods@#After exposing the right sciatic nerve, the sciatic nerve was crushed for 1 minute by a surgical clip. One day after nerve injury, dexmedetomidine (5, 25, and 50 µg/kg) was directly applied to the injured sciatic nerve once a day for 14 days. Walking track analysis was used to assess locomotor function and plantar test was conducted to assess thermal pain sensitivity. Immunohistochemistry was performed to determine the expression of c-Fos in the ventrolateral periaqueductal gray (vlPAG) and paraventricular nucleus (PVN). Western blot was used to evaluate the expression level of nerve growth factor (NGF) and myelin basic protein (MBP) in the sciatic nerve. @*Results@#SNCI resulted in deterioration of locomotor function and increased thermal pain sensitivity. The level of c-Fos expression in the PVN and vlPAG was increased and the level of NGF and MBP expression in the sciatic nerve was enhanced by SNCI. Dexmedetomidine treatment improved locomotor function and upregulated expression of NGF and MBP in the sciatic nerve of SNCI. Dexmedetomidine treatment alleviated thermal hyperalgesia and downregulated expression of c-Fos in the vlPAG and PVN after SNCI. @*Conclusions@#Dexmedetomidine may be used as a potential new treatment drug for recovery of locomotion and control of pain in peripheral nerve injury.
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BACKGROUND: A rapid increase in desflurane concentration has been demonstrated to induce transient sympathetic hyperactivity and lead to increases in blood pressure and heart rate (HR). Additionally, the use of dexmedetomidine as an anesthetic adjunct has been reported to attenuate intraoperative sympathetic responses. We examined the hemodynamic effects of dexmedetomidine infusion before anesthetic induction on desflurane-induced cardiovascular changes. METHODS: Patients were randomly divided into three groups. They received either normal saline (NS) (group 1, only NS) or dexmedetomidine solution diluted in 50 ml NS (group 2, 0.5 µg/kg; group 3, 1.0 µg/kg) for 10 minutes with a syringe pump before anesthetic induction. Desflurane was administered at a vaporizer dial setting of 8% for 5 minutes by manual ventilation. RESULTS: In group 1, the HR significantly increased above the baseline during the entire 5 minutes after desflurane inhalation and the mean blood pressure (MBP) significantly increased above the baseline at 1, 2, and 3 minutes after desflurane inhalation. However, in groups 2 and 3, the increases in HR and MBP induced by desflurane inhalation were significantly suppressed. The HR and MBP in group 2 remained closer to the baseline than in group 3. CONCLUSIONS: A loading infusion of dexmedetomidine for 10 minutes before induction of general anesthesia effectively attenuates the transient cardiovascular stimulation induced by desflurane inhalation, without significant hemodynamic side effects. The HR and MBP remained closer to the baseline after administration of 0.5 µg/kg dexmedetomidine than after administration of a dose of 1.0 µg/kg.
Assuntos
Humanos , Anestesia Geral , Pressão Sanguínea , Dexmedetomidina , Frequência Cardíaca , Hemodinâmica , Inalação , Nebulizadores e Vaporizadores , Seringas , VentilaçãoRESUMO
Acute coronary artery obstruction is a rare but fatal complication of surgical aortic valve replacement (AVR). Sudden coronary spasm, embolization of calcium plaque, and surgical factors can induce acute coronary syndrome after AVR. Here, we report a case of left main coronary ostial obstruction that occurred immediately after weaning from cardiopulmonary bypass. This case highlights the importance of coronary ostial flow patency and assessment of regional wall motion abnormalities with intraoperative transesophageal echocardiography in AVR.
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Síndrome Coronariana Aguda , Valva Aórtica , Cálcio , Ponte Cardiopulmonar , Vasos Coronários , Ecocardiografia , Ecocardiografia Transesofagiana , Espasmo , DesmameRESUMO
Acute coronary artery obstruction is a rare but fatal complication of surgical aortic valve replacement (AVR). Sudden coronary spasm, embolization of calcium plaque, and surgical factors can induce acute coronary syndrome after AVR. Here, we report a case of left main coronary ostial obstruction that occurred immediately after weaning from cardiopulmonary bypass. This case highlights the importance of coronary ostial flow patency and assessment of regional wall motion abnormalities with intraoperative transesophageal echocardiography in AVR.
Assuntos
Síndrome Coronariana Aguda , Valva Aórtica , Cálcio , Ponte Cardiopulmonar , Vasos Coronários , Ecocardiografia , Ecocardiografia Transesofagiana , Espasmo , DesmameRESUMO
A 28-year-old male patient with occipito-atlanto-axial instability underwent a cervical fusion with posterior technique. Post-operatively, the endotracheal tube (ETT) was removed, and the patient was transferred to the intensive care unit. After transfer, an upper airway obstruction developed and reintubations with a laryngoscope were attempted but failed. We inserted a #4 proseal laryngeal mask airway (LMA) and passed a 5.0 mm ETT through the LMA with the aid of a fiberoptic bronchoscope. We passed a tube exchanger through the 5.0 mm ETT and exchanged it with a 7.5 mm ETT. This method may be a useful alternative for difficult tracheal intubations.