Buono Romualdo Del, Pascarella Giuseppe, Costa Fabio, Agrò Felice Eugenio
Department of Anaesthesia, Intensive Care and Pain Management, Humanitas Mater Domini, Via Gerenzano 2, 21053 Castellanza (VA), Italy.
Department of Anaesthesia, Intensive Care and Pain Management, Università Campus Bio-Medico di Roma, via Álvaro del Portillo 21, 00128 Rome, Italy.
Saudi J Anaesth. 2020 Oct-Dec;14(4):442-445. doi: 10.4103/sja.SJA_171_20. Epub 2020 Sep 24.
In literature, there is plenty of material regarding regional anesthesia techniques and block safety, but lacks about block success prevision. The perfusion index (PI) is an oximetry reliability indicator, available on many monitors as non-invasive parameter, indicating the ratio of arterial blood flow (pulsatile flow) to venous, capillary, and tissue blood flow (non-pulsatile blood flow). We hypothesized that that analysis of PI variations after performing regional anesthesia could have a role in predicting a successful nerve block.
Twenty-four consecutive patients regularly scheduled for limb surgery in regional anesthesia were included in our observation. PI measurements were recorded before regional anesthesia, and 1, 2, 3, 5, and 10 min after needle withdrawal. Along with PI, also sensation to cold (ice test), tactile sensation, and motor function were recorded before regional anesthesia, and 1, 2, 3, 5, and 10 min after needle withdrawal on the limb where the block were performed.
Ten sciatic nerve blocks, 6 spinal anesthesia, 8 brachial plexus block were performed and resulted successful. In all cases, PI values tripled at 5 min after the block execution and increased linearly, reaching at 10 min an average PI value 3.8 times higher for the interscalene group, 4 times for the spinal group, and 8 for the sciatic group.
A tripled PI within 5 min from performing regional anesthesia showed to be a reliable indicator of nerve block success, but a bigger trial involving more patients and different anesthetic concentrations may be necessary to confirm this assumption.
在文献中，有大量关于区域麻醉技术和阻滞安全性的资料，但缺乏关于阻滞成功预测的内容。灌注指数（PI）是一种血氧饱和度测定的可靠性指标，在许多监护仪上作为无创参数可用，它表示动脉血流（搏动性血流）与静脉、毛细血管和组织血流（非搏动性血流）的比值。我们推测，分析区域麻醉后PI的变化可能有助于预测神经阻滞是否成功。
我们观察了连续24例计划在区域麻醉下进行肢体手术的患者。在区域麻醉前、拔针后1、2、3、5和10分钟记录PI测量值。除PI外，还在区域麻醉前以及在进行阻滞的肢体上拔针后1、2、3、5和10分钟记录冷觉（冰试验）、触觉和运动功能。
共进行了10例坐骨神经阻滞、6例脊髓麻醉、8例臂丛神经阻滞，均获成功。在所有病例中，阻滞实施后5分钟时PI值增至三倍，并呈线性增加，在10分钟时，肌间沟组平均PI值高出3.8倍，脊髓组高出4倍，坐骨神经组高出8倍。
区域麻醉后5分钟内PI值增至三倍是神经阻滞成功的可靠指标，但可能需要一项纳入更多患者和不同麻醉浓度的更大规模试验来证实这一假设。
