Huiku M, Uutela K, van Gils M, Korhonen I, Kymäläinen M, Meriläinen P, Paloheimo M, Rantanen M, Takala P, Viertiö-Oja H, Yli-Hankala A
Clinical Research, GE Healthcare Finland Oy, PO Box 900, FI-00031 GE, Helsinki, Finland.
Br J Anaesth. 2007 Apr;98(4):447-55. doi: 10.1093/bja/aem004. Epub 2007 Feb 28.
Inadequate analgesia during general anaesthesia may present as undesirable haemodynamic responses. No objective measures of the adequacy of analgesia exist. We aimed at developing a simple numerical measure of the level of surgical stress in an anaesthetized patient.
Sixty and 12 female patients were included in the development and validation data sets, respectively. All patients had elective surgery with propofol-remifentanil target controlled anaesthesia. Finger photoplethysmography and electrocardiography waveforms were recorded throughout anaesthesia and various waveform parameters were extracted off-line. Total surgical stress (TSS) for a patient was estimated based on stimulus intensity and remifentanil concentration. The surgical stress index (SSI) was developed to correlate with the TSS estimate in the development data set. The performance of SSI was validated within the validation data set during and before surgery, especially at skin incision and during changes of the predicted remifentanil effect-site concentration.
SSI was computed as a combination of normalized heart beat interval (HBI(norm)) and plethysmographic pulse wave amplitude (PPGA(norm)): SSI = 100-(0.7PPGA(norm)+0.3HBI(norm)). SSI increased at skin incision and stayed higher during surgery than before surgery; SSI responded to remifentanil concentration changes and was higher at the lower concentrations of remifentanil.
SSI reacts to surgical nociceptive stimuli and analgesic drug concentration changes during propofol-remifentanil anaesthesia. Further validation studies of SSI are needed to elucidate its usefulness during other anaesthetic and surgical conditions.
全身麻醉期间镇痛不足可能表现为不良的血流动力学反应。目前尚无评估镇痛充分性的客观指标。我们旨在开发一种简单的数值指标来衡量麻醉患者的手术应激水平。
分别有60例和12例女性患者纳入开发数据集和验证数据集。所有患者均接受丙泊酚-瑞芬太尼靶控麻醉下的择期手术。在整个麻醉过程中记录手指光电容积描记图和心电图波形，并离线提取各种波形参数。根据刺激强度和瑞芬太尼浓度估算患者的总手术应激（TSS）。在开发数据集中建立手术应激指数（SSI）以使其与TSS估算值相关。在验证数据集中，于手术期间及手术前对SSI的性能进行验证，尤其在皮肤切开时以及预测的瑞芬太尼效应室浓度变化期间。
SSI通过归一化心跳间期（HBI(norm)）和光电容积脉搏波振幅（PPGA(norm)）计算得出：SSI = 100 - (0.7 * PPGA(norm) + 0.3 * HBI(norm))。SSI在皮肤切开时升高，且在手术期间高于手术前；SSI对瑞芬太尼浓度变化有反应，在瑞芬太尼浓度较低时更高。
在丙泊酚-瑞芬太尼麻醉期间，SSI对手术伤害性刺激和镇痛药物浓度变化有反应。需要对SSI进行进一步的验证研究，以阐明其在其他麻醉和手术情况下的实用性。
