From the Departments of *Anesthesiology and †Biostatistics, University of Michigan, Ann Arbor, MI.
Reg Anesth Pain Med. 2014 Jan-Feb;39(1):13-7. doi: 10.1097/AAP.0000000000000024.
The use of self-report questionnaires to detect characteristics of altered central pain processing, as seen in centralized pain disorders such as fibromyalgia, allow for the epidemiological studies of pain patients. Here, we assessed the relationship between reporting high levels of pain while taking opioids and the presence of characteristics associated with centralized pain.
We evaluated 582 patients taking opioid medications using validated measures of clinical pain, neuropathic pain symptoms, mood, and functioning. A multivariate linear regression model was used to assess the association between levels of pain while taking opioids and presenting with characteristics consistent with having centralized pain.
We found that 49% of patients taking opioids continued to report severe pain (≥ 7/10). In multivariate analysis, factors associated with having higher levels of pain in opioid users included higher fibromyalgia survey scores (P = 0.001), more neuropathic pain symptoms (P < 0.001), and higher levels of depression (P = 0.002). Although only 3.2% were given a primary diagnosis of fibromyalgia by their physician, 40.8% met American College of Rheumatology survey criteria for fibromyalgia.
Our findings suggest that patients with persistently high pain scores despite opioid therapy are more likely than those with lower levels of pain to present with characteristics associated with having centralized pain. This study cannot determine whether these characteristics were present before (fibromyalgia-like patient) or after the initiation of opioids (opioid-induced hyperalgesia). Regardless, patients with a centralized pain phenotype are thought to be less responsive to opioids and may merit alternative approaches.
使用自报告问卷来检测中枢性疼痛处理改变的特征，这种改变在集中性疼痛障碍中可见，如纤维肌痛，这使得对疼痛患者进行流行病学研究成为可能。在这里，我们评估了在服用阿片类药物时报告高水平疼痛与存在与中枢性疼痛相关的特征之间的关系。
我们使用经过验证的临床疼痛、神经病理性疼痛症状、情绪和功能测量方法评估了 582 名服用阿片类药物的患者。使用多元线性回归模型来评估在服用阿片类药物时疼痛水平与呈现出与中枢性疼痛一致的特征之间的关联。
我们发现，49%服用阿片类药物的患者仍报告严重疼痛（≥7/10）。在多变量分析中，与阿片类药物使用者疼痛水平较高相关的因素包括纤维肌痛调查评分较高（P=0.001）、更多的神经病理性疼痛症状（P<0.001）和更高水平的抑郁（P=0.002）。尽管只有 3.2%的患者被其医生诊断为纤维肌痛，但40.8%的患者符合美国风湿病学会纤维肌痛调查标准。
我们的发现表明，尽管接受阿片类药物治疗，但疼痛评分持续较高的患者比疼痛水平较低的患者更有可能出现与中枢性疼痛相关的特征。这项研究无法确定这些特征是在（类纤维肌痛患者）之前还是在开始使用阿片类药物（阿片类药物诱导的痛觉过敏）之后存在。无论如何，具有中枢性疼痛表型的患者被认为对阿片类药物的反应性较低，可能需要替代方法。
