Effects of topical application of clonidine cream on pain behaviors and spinal Fos protein expression in rat models of neuropathic pain, postoperative pain, and inflammatory pain.

BACKGROUND: Clonidine can effectively reduce pain and/or hypersensitivity. However, the antihypersensitivity effects of clonidine topically applied in cream (CC) have not been investigated. The authors evaluated effects of topical application of CC on pain behaviors and spinal Fos-like immunoreactivity in rats with hypersensitivity. METHODS: Clonidine (30, 100, and 300 microg/g) was prepared in a cream base. In rat models of neuropathic pain, inflammatory pain, and postoperative pain, the authors evaluated effects of CC (0.1 g), topically applied onto the plantar surface of the injured or uninjured paw, on thermal hyperalgesia and mechanical allodynia to von Frey filaments. The authors also evaluated effects of CC on lumbar spinal Fos-like immunoreactivity. RESULTS: In neuropathic rats, CC applied onto the injured paw reduced thermal hyperalgesia and mechanical allodynia dose dependently, whereas CC applied onto the uninjured paw had no effect. The antihypersensitivity effects of CC were antagonized by intraperitoneal yohimbine (10 mg/kg). Further, CC reduced Fos-like immunoreactivity in neuropathic rats. In contrast, CC in a single dose had no effects on hyperalgesia, allodynia, or Fos-like immunoreactivity in rats with inflammatory or postoperative pain. In rats with postoperative pain, CC repeatedly applied for 6 days reduced thermal hyperalgesia, but not mechanical allodynia, in the postoperative days, whereas it had no effects on hyperalgesia or allodynia in those with inflammatory pain. CONCLUSIONS: Topical CC in concentrations examined significantly reduced hypersensitivity and lumbar spinal Fos-like immunoreactivity in rats with neuropathic pain, probably through activation of peripherally located alpha2 adrenoceptors. However, CC was only partially effective and totally ineffective in rats with postoperative pain and inflammatory pain, respectively.

[Sexual differences in effects and side effects of epidural morphine for VATS (video-associated thoracic surgery)].

BACKGROUND: VATS (video-associated thoracic surgery) is mainly undertaken under general anesthesia only. Considering with patient's respiratory stability and postoperative pain relief, epidural anesthesia has advantages over general anesthesia. According to our clinical experience, side effects of epidural morphine, especially nausea and vomiting, often torture patients, especially woman. METHODS: Epidural catheter was inserted before general anesthesia. Morphine 0-3mg was administered at the beginning of the operation and 0-4 mg was injected within 30hr after the operation. Effects and side effects of epidural morphine among 98 patients being operated by VATS were investigated backward with special attention to gender differences. The adverse effects noticed were thirst feeling, itching, nausea, vomiting and urinary retention. The use of rescue analgesics was also analyzed in each patient. RESULTS: Among 68 men and 30 women, dosage of epidural morphine was not significantly different by gender. As for the side effects, the significant gender difference was observed only in nausea and vomiting, showing 46.7% in female and 16.2% in male (P= 0.07). CONCLUSIONS: Statistically significant gender differences of effectiveness and side effects of epidural morphine in VATS were observed only in nausea and vomiting.

[The effects of hyperventilation upon spinal dorsal horn neuronal single-unit activities under nitrous oxide anesthesia].

BACKGROUND: The purpose of this study is to investigate the effects of hyperventilation upon spinal dorsal horn neuronal single-unit activities under nitrous oxide anesthesia. METHODS: Eight decerebrated spinal cats with laminectomy were maintained with oxygen and pancuronium bromide. Following the control period of normocapnia, 50% nitrous oxide was administered for 30 minutes after a hypocapnia period of 20-25 mmHg for 20 minutes. The recoveries of activities followed with normocapnia and pure oxygen administration. The changes of spontaneous and evoked activities by the pinching were investigated every 5 minutes after control study. RESULTS: Inhalation of 50% nitrous oxide suppressed the WDR neuronal activities and with hyperventilation the suppressions significantly increased. CONCLUSIONS: These results were compatible with clinical reports on the effectiveness of hyperventilation as a maintenance method under N2O anesthesia.

[Difficult airway in a child with multiple juvenile xanthogranulomas].

Juvenile xanthogranuloma (JXG) is a benign and self-healing histiocytosis on the skin. A 4-year-old boy with multiple JXG was scheduled for plastic surgery to correct the scar contraction of the neck. The patient was expected to have difficult airway caused by small mouth, limitation of neck movement and numerous nodular lesions located at the face. Initially he underwent resection of the neck scar under local anesthesia with added inhalation anesthesia via mask, and the restricted neck recurvation was improved. One week later, he underwent skin grafting under general anesthesia. We used a spiral tube of 3 mm diameter inserted to the nostril for manual ventilation, and bronchofiberscope-aided tracheal intubation was successfully performed through the laryngeal mask airway under general anesthesia without any problems.

[A case of latex anaphylactoid reaction starting with respiratory symptoms].

We report a case of latex anaphylactoid reaction in a 39-year-old man with aortitis. He was scheduled to undergo stent-graft implantation. When the operation progressed into his abdomen, respiratory symptoms, wheezing and high airway pressure, occurred. However, he did not show any dermal symptoms. Thirty-five minutes after the start of respiratory symptoms, his face suddenly showed flush, and intravenous epinephrine worked successfully against anaphylactoid reactions. There are anaphylactoid reactions which occurred with respiratory symptoms, and we should be aware of these cases.

[Perioperative management for carotid endoarterectomy with induced mild hypothermia: a case report].

We report perioperative management for carotid endoarterectomy with induced mild hypothermia in a patient with severe stenosis of the bilateral carotid arteries. The patient was a 47 year-old male with familial hyperlipidemia and history of coronary artery bypass surgery. Angiography revealed severe stenotic lesions of the right internal carotid artery (ICA) and total occlusion of the left ICA. Endoarterectomy for the right ICA was planned. Anesthesia was induced and maintained with fentanyl, midazolam, pancuronium and sevoflurane. Electroencephalogram and near-infrared cerebral oxymetry were employed for monitoring intraoperatively. Temporary shunting was used during clamping of the right carotid artery because collateral blood flow could not be expected due to total occlusion of the left ICA. Furthermore, mild hypothermia down to 34 degree C was induced for brain protection with the use of a cooling blanket. After the surgery, the patient was transferred to ICU under deep anesthesia and controlled ventilation. Anesthesia was lightened gradually after rewarming to prevent postoperative shivering. The patient left ICU on the second postoperative day without any neurological deficits.

Suppressive effect of spinal dorsal-horn neuronal activity by local spinal-cord cooling is reversed by naloxone in cats.

PURPOSE: The purpose of this study was to assess the effect of local spinal cord cooling on spinal dorsal-horn neuronal activity, with special emphasis on the role of endogenous opioid. METHODS: Decerebrate, spinal-cord-transected cats ( n= 30) were subjected to local spinal-cord irrigation, using 0.9 N saline solution (15 degrees C; n= 15, and 35 degrees C; n= 15) for 90 min. The extracellular, single-cell activity of spinal dorsal-horn neurons responding to noxious stimulation was recorded. Sixty-one minutes after induction of local spinal-cord irrigation, naloxone (0.1 mg.kg(-1)) was administered intravenously. Local spinal-cord blood flow was measured using the hydrogen clearance technique. RESULTS: Local spinal cord cooling produced significant suppression of both spontaneous and evoked activity (33.1 +/- 7.7% and 31.4 +/- 5.5%, respectively; mean +/- SE). Naloxone reversed this suppression immediately. Local spinal-cord blood flow was significantly reduced during spinal-cord cooling, but naloxone did not change local spinal-cord blood flow. CONCLUSION: The results demonstrate that endogenous opioids may play an important role in dorsal-horn neuronal suppression induced by local spinal-cord cooling.