Zwaag Jelle, Timmerman Hans, Pickkers Peter, Kox Matthijs
Department of Intensive Care Medicine, Radboud University Medical Center, Nijmegen, the Netherlands.
Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, the Netherlands.
J Pain Res. 2023 Jun 13;16:1979-1991. doi: 10.2147/JPR.S400408. eCollection 2023.
Evidence indicates that healthy individuals who follow a training program comprised hyperventilatory breathing exercises and cold exposure can voluntarily activate their sympathetic nervous system and attenuate their systemic inflammatory response during experimental endotoxemia (intravenous administration of bacterial endotoxin). Furthermore, trained participants reported less endotoxemia-induced flu-like symptoms. However, it remained to be determined whether the effects on symptoms are due to the mitigated inflammatory response or involve direct analgesic effects of (elements of) the training program.
In the present study, we used Nijmegen-Aalborg Screening Quantitative sensory testing (NASQ) to objectively map pain sensitivity using non-invasive stimuli to address this question. First, NASQ parameters were evaluated in 20 healthy volunteers before, during, and after the conduct of the hyperventilatory breathing exercise. Second, NASQ measurements were performed before and after 48 healthy volunteers followed different modalities of the training program: breathing exercise training, cold exposure training, the combination of both, or no training. Lastly, NASQ measurements were performed in these 48 subjects during experimental endotoxemia.
Electrical pain detection thresholds increased during the breathing exercise (p = 0.001) as well as four hours afterwards (p = 0.03). Furthermore, cold exposure training resulted in lower VAS scores during hand immersion in ice water (p < 0.001). Systemic inflammation induced by administration of endotoxin nullified the decreased pain perception during the ice water test in subjects trained in cold exposure.
A hyperventilatory breathing exercise decreases pain perception induced by an electrical stimulus. Furthermore, cold exposure training may decrease pain perception induced by hand immersion in ice water.
有证据表明，健康个体在进行包括过度通气呼吸练习和冷暴露的训练计划后，在实验性内毒素血症（静脉注射细菌内毒素）期间能够自主激活其交感神经系统并减弱全身炎症反应。此外，接受训练的参与者报告内毒素血症引起的类似流感症状较少。然而，对症状的影响是由于炎症反应减轻还是涉及训练计划（的要素）的直接镇痛作用仍有待确定。
在本研究中，我们使用奈梅亨-奥尔堡筛查定量感觉测试（NASQ），通过非侵入性刺激客观地绘制疼痛敏感性，以解决这个问题。首先，在20名健康志愿者进行过度通气呼吸练习之前、期间和之后评估NASQ参数。其次，在48名健康志愿者遵循不同训练计划模式（呼吸练习训练、冷暴露训练、两者结合或不训练）之前和之后进行NASQ测量。最后，在这48名受试者进行实验性内毒素血症期间进行NASQ测量。
呼吸练习期间（p = 0.001）以及之后四小时（p = 0.03），电痛检测阈值升高。此外，冷暴露训练导致手浸入冰水中时的视觉模拟评分（VAS）较低（p < 0.001）。内毒素给药引起的全身炎症消除了冷暴露训练受试者在冰水测试期间疼痛感知的降低。
过度通气呼吸练习可降低电刺激引起的疼痛感知。此外，冷暴露训练可能会降低手浸入冰水中引起的疼痛感知。
