Department of Anesthesia, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA.
Br J Anaesth. 2013 Apr;110(4):600-6. doi: 10.1093/bja/aes423. Epub 2012 Nov 27.
The aim of this study was to determine whether experimental pain tests (EPTs) using heat, pressure, and i.v. cannulation before induction of labour reliably predict epidural analgesic use and pain intensity during labour.
Fifty healthy women with singleton, term pregnancies admitted for scheduled induction of labour comprised the study population for this prospective case-controlled study. Heat and pressure threshold, tolerance, and suprathreshold VAS pain ratings were determined using a Medoc thermal sensory analyser and Somedic pressure algometer, respectively, after admission before induction of labour. Verbal pain scores (VPS 0-10) were determined during peripheral 18 G i.v. placement. Response outcomes included time to epidural request, pain at epidural, labour pain [area under the curve (AUC) and worse score], and epidural local anaesthetic use. Bivariate analysis followed by forward-backward multiple regression modelling was performed to determine relationships between EPTs and labour pain response measures.
Heat tolerance was significantly correlated with worst labour pain (r=0.33, P=0.025) and pain with i.v. cannulation was correlated with time to epidural request (r=0.33, P=0.025). Multiple linear regression analysis found that labour pain AUC could be predicted with suprathreshold heat VAS, heat tolerance, and pressure tolerance (R(2)=0.26; P=0.007). There were strong correlations among the various pre-labour QSTs.
Pre-labour EPTs were not very reliable at predicting the labour pain experience. Consistent with postoperative studies, suprathreshold and tolerance tests appear more useful than the threshold for predicting labour pain responses. Pain rating during i.v. cannulation (an easy, rapid, point-of-care test) showed some utility as an EPT.
本研究旨在确定在诱导分娩前进行热、压力和静脉置管的实验性疼痛测试（EPT）是否能可靠地预测分娩时硬膜外镇痛的使用和疼痛强度。
本前瞻性病例对照研究纳入了 50 名健康的单胎足月妊娠妇女，这些妇女因计划分娩而入院。在诱导分娩前入院后，使用 Medoc 热感觉分析仪和 Somedic 压力测痛计分别测定热和压力阈值、耐受度和超阈值 VAS 疼痛评分。在进行外周 18G 静脉置管时，记录口头疼痛评分（VPS 0-10）。反应结果包括硬膜外请求时间、硬膜外疼痛、分娩疼痛[曲线下面积（AUC）和最差评分]和硬膜外局部麻醉药使用。进行了双变量分析，然后进行了向前-向后多元回归建模，以确定 EPT 与分娩疼痛反应测量之间的关系。
热耐受度与最差分娩疼痛显著相关（r=0.33，P=0.025），静脉置管疼痛与硬膜外请求时间相关（r=0.33，P=0.025）。多元线性回归分析发现，劳动疼痛 AUC 可以用超阈值热 VAS、热耐受度和压力耐受度来预测（R(2)=0.26；P=0.007）。各种产前 QST 之间存在很强的相关性。
产前 EPT 并不能非常可靠地预测分娩疼痛体验。与术后研究一致，超阈值和耐受度测试似乎比阈值更能预测分娩疼痛反应。静脉置管时的疼痛评分（一种简单、快速、即时的床边测试）作为 EPT 具有一定的应用价值。
