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Objective To evaluate the efficacy of ultrasound for placement of laryngeal mask airway (LMA) in comparison with fiberoptic bronchoscope in adult patients.Methods Fifty-eight ASA physical status Ⅰ or Ⅱ patients,aged 18-57 yr,weighing 50-70 kg,with body mass index 20-30 kg/m2,scheduled for gynecological operation under general anesthesia,underwent standard general anesthetic technique with 4 # LMA-ClassicTM.After clinical assessment of correct placement of LMA,the position of the LMA was confirmed by transverse neck ultrasound,and reconfirmed using fiberoptic bronchoscopy.The peak airway pressure and oropharyngeal leak pressure were recorded.Results When the outcome of clinical assessment of correct placement of LMA was considered as satisfactory,the rate of ideal anatomic placement assessed by ultrasound evaluation was 69 %,and the rate of ideal anatomic placement assessed by fiberoptic bronchoscopy was 59 %,and it showed that there was no significant difference in detecting the ideal placement of the LMA (P ＞ 0.05).The oropharyngeal leak pressure was significantly higher when ultrasound was used for confirmation of the correct placement of LMA than that when fiberoptic bronchoscope was used (P ＜ 0.05).Conclusion Ultrasound provides better efficacy for placement of LMA in indicating sealing of LMA than fiberoptic bronchoscope and is helpful in improving ventilation conditions in adult patients.
RESUMO
Objective To investigate the effects of surgical trauma on synaptic structure in hippocampal CA3 area in aged rats.Methods Fifty-six healthy SD rats aged 18 months were randomly divided into 3 groups: control group (group C, n = 8) , anesthesia group (group A, n = 24) , and operation group (group O, n - 24) . Anesthesia was performed with intraperitoneal ketamine 40 mg/kg but no operation was carried out in group A. Anesthesia was also performed with intraperitoneal ketamine 40 mg/kg, and splenectomy was performed after loss of righting reflex in group O. Eight animals from group A and O selected on 1, 3, and 7 d after anesthesia or operation respectively underwent Morris water maze test for assessment of the cognitive function. The animals were . then decapitated. Hippocampal CA3 area was isolated for examination with electron microscope and the synaptic structure in the polymorphic layer of hippocampal CA3 area was measured. Results Compared to group C and A, the times of passing through the original platform and number of synapses were significantly reduced, the width of synaptic cleft was significantly increased, the thickness of the postsynaptic density was significantly decreased, the length of the active zones was significantly shortened, and the curvature of the synaptic interface and percentage of perforated synapses were significantly decreased at T_(1,2), ( P < 0.05 or 0.01) , but no significant change was found in the indices mentioned above at T_3 in group O(P > 0.05). Compared to group C, the latency and swimming distance were significantly prolonged at T_1 in group A and at T_(1,2) in group O ( P < 0.01) . Compared to group A, the latency at T_(1,2) and the swimming distance at T_2 were significantly prolonged in group O ( P < 0.05) . Conclusion Surgical trauma can induce early postoperative cognitive impairment through changing synaptic structure in hippocampal CA3 area in aged rats.