Tugcugil E, Besir A
Department of Anesthesiology and Reanimation, Medical Faculty of Karadeniz Teknik University, Trabzon, Turkey.
Niger J Clin Pract. 2021 Jan;24(1):115-120. doi: 10.4103/njcp.njcp_79_20.
The use of paravertebral block (PVB) for postoperative analgesia in the thoracic surgery has increased in recent years. However, the traditional methods used to evaluate the success and adequacy of the block are time-consuming, subjective and depend on the patient's compliance. Therefore, the search still continues to find a method to objectively evaluate the success and adequacy of the paravertebral block.
The aim of this study was to investigate whether the Perfusion Index (PI) measured by pulse oximetry technology was an early and quantitative marker for the success of PVB. We also aimed to compare the PI and pinprick method.
The study included a total of 38 patients undergoing elective thoracotomy surgery within the age group of 18-65 years, with class I-II American Society of Anesthesiologists' (ASA) physical status classification. Thoracic PVB was performed for all patients using 20 mL of 5% bupivacaine under ultrasound guidance. After the block was performed, PI measurements were made from the finger and earlobe of the block side for 30 minutes at one-minute intervals. The spread of the block to the anterior chest wall T3-T8 dermatomes was recorded by pinprick sensory test before the block application and fifth, 10, 15, 20, and 30 minutes following the block application.
The PI value measured from the finger on the block side increased 1.5 times compared to the baseline value 12 minutes after the block application (p < 0.05). The sensitivity and specificity of PI in determining the success of PVB at 12th minute were 67% and 85%, respectively. Positive predictive value [PPV] was 93% and negative predictive value [NPV] was 75%. The accepted cut-off PI value was found to be 0.84 for a successful PVB. A weak positive correlation was observed between PI and pinprick test (rs = 0.35, P < 0.05).
The present study has shown that PI is an objective, fast, practical and non-invasive method, when compare with pinprick method, that can be used to evaluate PVB success.
近年来，椎旁阻滞（PVB）在胸外科手术术后镇痛中的应用有所增加。然而，用于评估阻滞成功与否及充分性的传统方法耗时、主观且依赖患者的配合。因此，仍在继续寻找一种客观评估椎旁阻滞成功与否及充分性的方法。
本研究旨在探讨通过脉搏血氧饱和度技术测量的灌注指数（PI）是否是椎旁阻滞成功的早期定量指标。我们还旨在比较PI与针刺法。
本研究共纳入38例年龄在18 - 65岁之间、美国麻醉医师协会（ASA）身体状况分级为I - II级的择期开胸手术患者。在超声引导下，为所有患者实施20 mL 5%布比卡因的胸椎旁阻滞。阻滞实施后，在1分钟间隔内，对阻滞侧手指和耳垂进行30分钟的PI测量。在阻滞应用前以及应用后第5、10、15、20和30分钟，通过针刺感觉测试记录阻滞向前胸壁T3 - T8皮节的扩散情况。
阻滞应用12分钟后，阻滞侧手指测量的PI值较基线值增加了1.5倍（p < 0.05）。PI在第12分钟确定PVB成功的敏感性和特异性分别为67%和85%。阳性预测值[PPV]为93%，阴性预测值[NPV]为75%。成功的PVB的可接受PI临界值为0.84。PI与针刺测试之间观察到弱正相关（rs = 0.35，P < 0.05）。
本研究表明，与针刺法相比，PI是一种客观、快速、实用且无创的方法，可用于评估PVB的成功与否。
