目的：硬膜外低濃度局部麻醉劑結合鴉片類藥物廣泛被使用於自然生產的止痛上。然而硬膜外低濃度局部麻醉劑是否可以降低交感神經阻斷，目前仍不清楚。方法：本研究選取40 位自然生產的初產婦，將這些病人隨機平分為A、B 兩組。A 組的產婦給予15 ml 含有50μg 吩坦尼的0.07% 羅派卡因；B 組中的產婦則給予15 ml 0.25% 羅派卡因。接著經由硬膜外導管每小時給予12 ml 含有2 μg/ml 吩坦尼的0.07% 羅派卡因。在硬膜外給藥前以及給藥三十分鐘後，我們使用皮膚溫度探頭與雷射都卜勒血流計測量了兩組產婦手、腳的皮膚溫度與血流。結果：B 組產婦腳的皮膚溫度在硬膜外止痛三十分鐘後與A 組產婦比較起來明顯上升（A 組：+0.5 ± 1.3 °C；B 組：+3.5 ± 2.4 °C；p < 0.001）。B 組產婦腳的皮膚血流在止痛後也明顯增加（A 組：+9 ± 62%；B 組：+195 ± 318%；p = 0.01）。相對的，B 組產婦手的皮膚溫度與血流是下降的，而A 組產婦手的皮膚溫度與血流則略有上升（p 值分別為0.01 與0.09）。結論：我們的研究顯示15 ml 硬膜外0.07% 羅派卡因加上50μg 吩坦尼使用於自然生產，可以減少交感神經阻斷，並在生產初期提供良好的止痛作用。

Objective: Epidural low concentration local anesthetics combined with opioids are widely used in labor analgesia. However, whether epidural low concentration local anesthetics decrease the degree of sympathetic block is not clear. Methods: Forty nulliparous parturients admitted for spontaneous vaginal delivery were enrolled and randomly assigned into group A and B. Epidural labor analgesia was initiated with 15 ml 0.07 % ropivacaine with 50 μg fentanyl for group A parturients and 15 ml of 0.25 % ropivacaine for group B parturients followed by a 12 ml/hr infusion of 0.07% ropivacaine plus 2 μg/ml fentanyl. Skin temperature and skin blood flow of the hand and foot were measured before and 30 minutes after the beginning of epidural analgesia by the temperature probe and laser-Doppler flowmetry. Results: Skin temperature of the foot increased more in group B parturients 30 min after epidural analgesia than group A parturients (Group A: +0.5 ± 1.3 °C; Group B: +3.5 2.4 °C; p < 0.001). Skin blood flow of the foot also significantly increased in group B parturients (Group A: +9 ± 62%; Group B: +195 ± 318%; p = 0.01). On the contrary, skin temperature and blood flow of the hand slightly decreased in group B parturients but slightly increased in group A parturients (p = 0.01 and 0.09, respectively). Conclusions: Epidural 15 ml 0.07% ropivacaine plus 50μg fentanyl for labor analgesia produced less sympathetic block and also provided good quality of analgesia at the beginning of labor.