求翻译：硬膜外阻滞麻醉的失败率和阻滞不全发生率较高,有文献报道高达20%[5,6]。当硬膜外阻滞应用于下腹部手术时,由于手术操作游离、牵拉组织器官,易引起患者内脏牵拉性疼痛,表现为精神紧张, 焦虑，患者常诉胸口闷痛难受、恶心、牵拉痛,甚至呕吐、鼓肠、心率减慢等，降低对手术的满意度，甚至产生一些意外。临床上，常常给予一些辅助麻醉药物，如杜氟合剂，芬太尼，力月西等等。根据瑞芬太尼的药理特点，和MAC内涵的延伸，已有报道将瑞芬太尼泵注用于术中MAC，显示出其一定的优势。是什么意思？

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Hard film, the failure rate and clogged clogged anesthesia is not the whole with higher incidence in some literature, up to 20 per cent reported [5, 6] . When the hard coating, applied to the workmen, because the procedure when abdominal surgery operating free radicals, pulling tissues stretched off

Failure rates of epidural block anesthesia and block incomplete high incidence, literature reports up to 20%[5,6]. When the epidural anesthesia applied to the lower abdomen surgery, due to surgical operation free, pulling tissues and organs, caused patients with visceral pain, stress, anxiety, patie