Bruins Arnoud A, Kistemaker Kay R J, Boom Annemieke, Klaessens John H G M, Verdaasdonk Rudolf M, Boer Christa
Department of Anesthesiology, Institute for Cardiovascular Research, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
Spaarne Gasthuis, Spaarnepoort 1, 2134 TM, Hoofddorp, The Netherlands.
J Clin Monit Comput. 2018 Apr;32(2):335-341. doi: 10.1007/s10877-017-0026-y. Epub 2017 May 15.
Due to the high rates of epidural failure (3-32%), novel techniques are required to objectively assess the successfulness of an epidural block. In this study we therefore investigated whether thermographic temperature measurements have a higher predictive value for a successful epidural block when compared to the cold sensation test as gold standard. Epidural anesthesia was induced in 61 patients undergoing elective abdominal, thoracic or orthopedic surgery. A thermographic picture was recorded at 5, 10 and 15 min following epidural anesthesia induction. After 15 min a cold sensation test was performed. Epidural anesthesia is associated with a decrease in skin temperature. Thermography predicts a successful epidural block with a sensitivity of 54% and a PPV of 92% and a specificity of 67% and a NPV of 17%. The cold sensation test shows a higher sensitivity and PPV than thermography (97 and 93%), but a lower specificity and NPV than thermography (25 and 50%). Thermographic temperature measurements can be used as an additional and objective method for the assessment of the effectiveness of an epidural block next to the cold sensation test, but have a low sensitivity and negative predictive value. The local decrease in temperature as observed in our study during epidural anesthesia is mainly attributed to a core-to-peripheral redistribution of body heat and vasodilation.
由于硬膜外阻滞失败率较高（3%-32%），因此需要新的技术来客观评估硬膜外阻滞的成功率。在本研究中，我们调查了与作为金标准的冷觉测试相比，热成像温度测量对成功的硬膜外阻滞是否具有更高的预测价值。对61例接受择期腹部、胸部或骨科手术的患者实施硬膜外麻醉。在硬膜外麻醉诱导后5、10和15分钟记录热成像图片。15分钟后进行冷觉测试。硬膜外麻醉与皮肤温度降低有关。热成像预测成功硬膜外阻滞的敏感性为54%，阳性预测值为92%，特异性为67%，阴性预测值为17%。冷觉测试显示出比热成像更高的敏感性和阳性预测值（分别为97%和93%），但特异性和阴性预测值低于热成像（分别为25%和50%）。除冷觉测试外，热成像温度测量可作为评估硬膜外阻滞效果的一种额外的客观方法，但敏感性和阴性预测值较低。我们的研究中观察到的硬膜外麻醉期间局部温度降低主要归因于体热从核心到外周的重新分布和血管舒张。
