Wennervirta J, Hynynen M, Koivusalo A-M, Uutela K, Huiku M, Vakkuri A
Department of Anesthesiology and Intensive Care Medicine, Helsinki University Hospital, Helsinki, Finland.
Acta Anaesthesiol Scand. 2008 Sep;52(8):1038-45. doi: 10.1111/j.1399-6576.2008.01687.x.
No validated monitoring method is available for evaluating the nociception/antinociception balance. We assessed the surgical stress index (SSI), computed from finger photoplethysmographic waveform amplitudes and pulse-to-pulse intervals, in patients undergoing shoulder surgery under general anesthesia (GA) and interscalene plexus block and in patients with GA only.
In this prospective, randomized study in 26 patients, increased blood pressure (BP) or heart rate, movement, and coughing were considered to be signs of intraoperative nociception and were treated with alfentanil. GA was maintained with desflurane aiming at a State Entropy level of 50. Photoplethysmographic waveforms were collected from the contra-lateral arm to the surgery and SSI values from 0 (no surgical stress) to 100 (maximal surgical stress) were calculated off-line.
Two minutes after skin incision, SSI had not increased in the plexus group and was lower in the plexus group (38 +/- 13) compared with the controls (58 +/- 13, P<0.005). Among the controls, 1 min before alfentanil administration, the SSI value was higher than during periods of adequate antinociception, 59 +/- 11 vs. 39 +/- 12 (P<0.01). The total cumulative need for alfentanil was higher in controls (2.7 +/- 1.2 mg) compared with the plexus group (1.6 +/- 0.5 mg; P=0.008). Tetanic stimulation to the ulnar region of the hand increased SSI significantly only among the patients with plexus block not covering the site of the stimulation.
SSI values were lower in patients with plexus block covering the sites of nociceptive stimuli. In detecting nociceptive stimuli, SSI had better performance than heart rate, BP, or response entropy.
目前尚无经过验证的监测方法可用于评估伤害感受/抗伤害感受平衡。我们评估了手术应激指数（SSI），该指数由手指光电容积脉搏波幅度和逐搏间期计算得出，研究对象为接受全身麻醉（GA）联合肌间沟神经丛阻滞的肩部手术患者以及仅接受GA的患者。
在这项针对26例患者的前瞻性随机研究中，血压（BP）或心率升高、运动及咳嗽被视为术中伤害感受的体征，并使用阿芬太尼进行处理。使用地氟烷维持GA，目标状态熵水平为50。从手术对侧手臂采集光电容积脉搏波，并离线计算SSI值，范围为0（无手术应激）至100（最大手术应激）。
皮肤切开后两分钟，神经丛阻滞组的SSI未升高，且神经丛阻滞组（38±13）的SSI低于对照组（58±13，P<0.005）。在对照组中，给予阿芬太尼前1分钟，SSI值高于抗伤害感受充分时，分别为59±11和39±12（P<0.01）。对照组阿芬太尼的总累积需求量（2.7±1.2 mg）高于神经丛阻滞组（1.6±0.
