The Compared Study of Importance of Concentration and Volume of Analgesic Solution on Patient - controlled Epidural Analgesia <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

何　农 硕士研究生 Nong He
徐秀征 Xiuzheng Xu 北京首钢总医院麻醉科，北京 100041
Department of Anesthesiology , Shougang General hospital , Beijing 100041
薛富善 教授 Fushan Xue
李　平 Ping Li
孙海燕 Haiyan Sun
中国协和医科大学中国医学科学院整形外科医院麻醉科，北京100041
Department of Anesthesiology ,Plastic Surgery Hospital , Beijing Union Medical College and Chinese Academy of Medical Science , Beijing 100041

ABSTRACT

Objective：To observe importance of concentration and volume of analgesic solution on patient-controlled epidural analgesia(PCEA).
Methods：This study was designed to compare analgesic and other effects of two kinds of analgesic solution, whose concentration and volume were not same, but whose total doses were same in 60 patients undergoing elective cesarean section. VAS, sedation, nausea, vomiting, itching, respiratory rate, times of PCEA and level of analgesia of patients were measured and recorded at same time-points 48 hours after operation.
Results：The analgesic effect of high volume-low concentration analgesic solution was significantly better than low volume-high concentration analgesic solution.
Conclusions：The volume of analgesic solution was more important than concentration for the analgesic effect of PCEA in postoperative patients undergoing elective cesarean section.
Key Words：Cesarean section; Patient-controlled epidural analgesia; Analgesic solution; Concentration; Volume; analgesic effect

    无论是硬膜外间隙阻 麻醉药还是外间隙镇痛，药物浓度和容积的问题一直是众多学者争论的焦点^[1,2]。本研究在单位时间内输注两种浓度和容积不同但总剂量相同的镇痛液进行病人自控硬膜外镇痛(patient controlled epidural analgesia, PCEA), 通过比较PCEA的镇痛效果及相关影响，初步探索两种因素在PCEA中的重要性，旨在为临床有效应用PCEA提供资料。

材料和方法<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

一般资料
　　选择ASA I～II 级，择期实施新式子宫下段剖宫产术（耻骨联合上3cm横切口）的孕妇60名，体重63～85kg，身高153～169cm，年龄26～35岁。将患者随机分成A、B两组，每组30名。

麻醉方法
　　手术前一天，麻醉医师在病房指导病人VAS 表的使用以及手术后镇痛泵的操作方法。手术前30min肌内注射阿托品0.5mg。进入手术室后测量血压、心率、呼吸频率、SpO₂和ECG，并插入导尿管。建立静脉通路后，病人左侧卧位，在L_2～3椎间隙采用Touhy硬膜外间隙穿刺针进行穿刺，用负压法和阻力消失法证实穿刺针已进入硬膜外间隙后，向头侧置入硬膜外导管3cm。用胶布固定硬膜外导管后，病人取平卧位。注入2%利多卡因3ml的实验剂量，观察8min，如无全脊椎麻醉等不良现象，并且有初步的麻醉平面后，再次注入2%利多卡因8ml。10min后测定麻醉平面，可以满足手术需要后开始手术。手术中每40min追加首次局部麻醉药剂量的一半。
手术后镇痛方法
　　手术结束后在硬膜外间隙注射0.5%布比卡因5ml和吗啡1mg，然后连接镇痛泵（韩国，奥美）。A组病人的镇痛液为0.125%布比卡因、0.002%吗啡和0.005%氟哌利多的混合液；背景输注速度为2ml/h，单次给药剂量为3.5ml/次，间隔时间为40min。B组病人的镇痛液为0.0625%布比卡因、0.0025%吗啡和0.0025%氟哌利多的混合液；背景输注速度为4ml/h，单次给药剂量为7ml/次，间隔时间为40min。手术后4h、8h、12h、24h和48h时记录视觉模糊评分法（VAS）、镇静程度、恶心、呕吐、瘙痒、呼吸频率、SpO₂、PECA次数、镇静平面。患者镇静程度的评估采用以下标准：1=清醒 / 焦虑；2=清醒 / 平静；3=清醒 / 嗜睡；4=睡眠 / 易唤醒；5=睡眠 / 难唤醒；6=睡眠 / 不能唤醒，在手术后48h时停止使用镇痛泵。

　　本实验结果表明，在实施子宫下段剖宫产患者手术后采用PCEA进行手术后镇痛治疗时，使用大量低浓度的镇痛液可能更具有优势。<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

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