Salomäki T E, Laitinen J O, Vainionpää V, Nuutinen L S
Department of Anaesthesiology, University of Oulu, Finland.
Reg Anesth. 1995 Sep-Oct;20(5):435-43.
Although local anesthesia has been demonstrated to potentiate spinal morphine analgesia in animal studies, results comparing epidural local anesthesia/opioid mixtures with opioid alone are contradictory in clinical studies. The hypothesis was that, although the concentration of bupivacaine (0.1%) was low to minimize its adverse effects, if the infusion rate of a fentanyl/bupivacaine solution was closely adjusted according to need, the presence bupivacaine would reduce the requirement for epidural fentanyl.
Forty patients were randomly assigned to receive either fentanyl (10 micrograms/mL) or a fentanyl/bupivacaine (0.1%) mixture epidurally corresponding to the dermatome of the surgical incision in a double-blind fashion for the first 18 hours after major abdominal surgery. The infusion was titrated for each patient to the rate required for pain relief during forced inspiration (pain score < or = 2, maximum 10). Pain scores, the fentanyl doses required, plasma concentrations of fentanyl at 18 hours, and the incidence and severity of adverse effects were recorded.
Patients reported similar median pain scores and were equally satisfied with pain relief in both groups. The mean required post-operative fentanyl infusion rate (57.7 +/- 19.5 micrograms/h) and the plasma concentrations (0.84 +/- 0.36 ng/mL) in the fentanyl group were comparable to the infusion rate (54.4 +/- 19.2 micrograms/h) and the plasma concentrations (0.86 +/- 0.36 ng/mL) in the fentanyl/bupivacaine group. Respiratory and cardiovascular functions were preserved, and the incidence of nausea, pruritus, and periods of drowsiness or sleep were similar in both groups.
In low concentrations (0.1%), bupivacaine did not reduce the titrated dose of epidural fentanyl required for adequate pain relief during forced inspiration after major abdominal surgery. The incidence and severity of adverse effects were also comparable whether or not low-dose bupivacaine infusion was used.
尽管在动物研究中已证实局部麻醉可增强脊髓吗啡镇痛效果，但在临床研究中，比较硬膜外局部麻醉/阿片类药物混合物与单纯阿片类药物的结果相互矛盾。假设是，尽管布比卡因（0.1%）的浓度较低以尽量减少其不良反应，但如果根据需要密切调整芬太尼/布比卡因溶液的输注速率，布比卡因的存在会降低硬膜外芬太尼的需求量。
40例患者在腹部大手术后的前18小时被随机分配，以双盲方式硬膜外给予芬太尼（10微克/毫升）或芬太尼/布比卡因（0.1%）混合物，对应手术切口的皮节。针对每位患者，将输注速率滴定至强迫吸气时缓解疼痛所需的速率（疼痛评分≤2，最高10分）。记录疼痛评分、所需芬太尼剂量、18小时时芬太尼的血浆浓度以及不良反应的发生率和严重程度。
两组患者报告的中位疼痛评分相似，对疼痛缓解的满意度相同。芬太尼组术后所需芬太尼的平均输注速率（57.7±19.5微克/小时）和血浆浓度（0.84±0.36纳克/毫升）与芬太尼/布比卡因组的输注速率（54.4±19.2微克/小时）和血浆浓度（0.86±0.36纳克/毫升）相当。呼吸和心血管功能得以维持，两组恶心、瘙痒以及嗜睡或睡眠期的发生率相似。
低浓度（0.1%）的布比卡因并未降低腹部大手术后强迫吸气时充分缓解疼痛所需的硬膜外芬太尼滴定剂量。无论是否使用低剂量布比卡因输注，不良反应的发生率和严重程度也相当。
