Can we predict persistent postoperative pain by testing preoperative experimental pain?

Although it is recognized that medical and surgical procedures may lead to persistent postoperative pain, predicting which patients are at risk for developing chronic pain presents an ongoing challenge. Clinical observations indicate that similar invasive procedures associated with consequent peripheral tissue damage can cause a wide range of pain experience. This broad variability is likely a consequence of the diversity in the central pain processing of the peripherally generated noxious stimulation. Therefore, advanced psychophysical measures that dynamically represent central pain modulation mechanisms may be used to determine an individual's susceptibility to developing persistent postoperative pain. This review highlights how, and to what extent, preoperative experimental pain testing can be utilized in predicting persistent postoperative pain.

Conflicting findings emerged regarding the role of traditional experimental pain tests, including pain threshold, supra-threshold magnitude estimation, and tolerance in the prediction of acute postoperative pain. Less efficient endogenous modulation and greater sensitization, as preoperatively assessed by advanced experimental pain tests, were associated with higher persistent postoperative pain scores.

The preoperative identification of individuals who have enhanced pain sensitivity and are at risk for developing persistent postoperative pain is important to providing them with better treatment that is specifically tailored to their altered pain modulation, as represented psychophysically.