Rantanen M, Yppärilä-Wolters H, van Gils M, Yli-Hankala A, Huiku M, Kymäläinen M, Korhonen I
Department of Anaesthesia, Tampere University Hospital, PO Box 2000, FIN-33521 Tampere, Finland.
Br J Anaesth. 2007 Oct;99(4):509-13. doi: 10.1093/bja/aem200. Epub 2007 Jul 27.
To study adequate antinociception during general anaesthesia, tetanic stimulus of 5-10 s duration has been used previously as a standardized nociceptive stimulus. However, such stimuli have been found to correlate poorly with intraoperative nociception. We hypothesized that an electrical tetanic stimulus of the ulnar nerve, lasting 30 s, would provide a reliable experimental pain model.
Thirty-three patients, undergoing open abdominal surgery, were studied. Propofol and remifentanil were used for anaesthesia. Patients were randomized to receive remifentanil at three target-controlled infusion levels (1, 3, or 5 ng ml(-1)) during short (5 s, Tet5) and a long-lasting (30 s, Tet30) tetanic (50 mA, 50 Hz) stimulus and skin incision. RR intervals (RRI) were obtained from the ECG and the mean RRI before each stimulus (Tet5, Tet30, incision) was compared with that after the stimulus.
At remifentanil level 1 ng ml(-1), the RRI responses to tetanic stimuli and skin incision were prominent but with higher concentrations (3 and 5 mg ml(-1)), responses were very small. Tet30 (r(2)=0.780) was the best predictor of the RRI response to skin incision when compared with Tet5 (r(2)=0.611), remifentanil level (r(2)=0.340), or propofol level (r(2)=0.036).
Long-lasting tetanic stimulus of ulnar nerve may provide a better experimental pain model for surgical pain during general anaesthesia than shorter stimuli, which have been applied in earlier studies.
为研究全身麻醉期间的充分镇痛效果，以往曾使用持续5 - 10秒的强直刺激作为标准化伤害性刺激。然而，已发现此类刺激与术中伤害感受的相关性较差。我们推测，持续30秒的尺神经电强直刺激将提供一个可靠的实验性疼痛模型。
对33例接受开腹手术的患者进行研究。采用丙泊酚和瑞芬太尼进行麻醉。患者被随机分为三组，在短时间（5秒，Tet5）和长时间（30秒，Tet30）的强直（50毫安，50赫兹）刺激及皮肤切开期间，分别接受三种靶控输注水平（1、3或5纳克/毫升）的瑞芬太尼。从心电图获取RR间期（RRI），并将每次刺激（Tet5、Tet30、切开）前的平均RRI与刺激后的平均RRI进行比较。
在瑞芬太尼水平为1纳克/毫升时，对强直刺激和皮肤切开的RRI反应显著，但在较高浓度（3和5微克/毫升）时，反应非常小。与Tet5（r² = 0.611）、瑞芬太尼水平（r² = 0.340）或丙泊酚水平（r² = 0.036）相比，Tet30（r² = 0.780）是对皮肤切开RRI反应的最佳预测指标。
与早期研究中应用的较短刺激相比，尺神经的长时间强直刺激可能为全身麻醉期间的手术疼痛提供更好的实验性疼痛模型。
