Talke Pekka, Talke Isabel
Department of Anesthesia and Perioperative Medicine, University of California San Francisco, San Francisco, CA, USA.
California Polytechnic State University, San Luis Obispo, CA, USA.
J Pain Res. 2024 Jan 9;17:209-217. doi: 10.2147/JPR.S443058. eCollection 2024.
Tetanic stimuli are used as standardized noxious inputs to investigate nociception. Previous studies have applied tetanic stimuli to various anatomical locations without validating that the resulting physiological responses were independent of the location where tetanic stimuli were applied. Our aim was to investigate the effects of three anatomical tetanic stimulus application sites on physiological variables reflecting autonomic nervous system responses as measured by photoplethysmography (PPG).
Under general anesthesia, a five second, 100 hertz, 70 milliamp tetanic stimulus was applied to the ulnar nerve, medial side of the tibia, and thorax (T5 dermatome) (N=12). The effect of tetanic stimuli on PPG-derived variables (AC, DC, and ACDC) and pulse rate at each stimulus location was determined using repeated-measures analysis of variance (ANOVA) followed by Dunnett's post hoc test. Maximum tetanic stimulus-induced changes in PPG-derived variables and pulse rates were compared among the three stimulus locations using ANOVA.
AC and ACDC values of PPG decreased, and the DC values of PPG increased in response to tetanic stimuli-induced vasoconstriction at each location (<0.001 for all). The maximum changes in the AC, ACDC, and DC values did not differ between locations (=NS). There were no significant changes in pulse rate (=NS).
The results showed that tetanic stimulation at either of these three locations provides the same autonomic nervous system responses, as measured by PPG.
ClinicalTrials.gov; NCT03648853.
强直刺激被用作标准化的有害输入来研究痛觉感受。先前的研究已将强直刺激应用于各种解剖位置，但未验证由此产生的生理反应是否独立于强直刺激的应用位置。我们的目的是研究三个解剖学上的强直刺激应用部位对通过光电容积脉搏波描记法（PPG）测量的反映自主神经系统反应的生理变量的影响。
在全身麻醉下，对尺神经、胫骨内侧和胸部（T5皮节）施加5秒、100赫兹、70毫安的强直刺激（N = 12）。使用重复测量方差分析（ANOVA），然后进行Dunnett事后检验，确定每个刺激部位的强直刺激对PPG衍生变量（AC、DC和ACDC）和脉搏率的影响。使用ANOVA比较三个刺激部位之间强直刺激引起的PPG衍生变量和脉搏率的最大变化。
在每个部位，PPG的AC和ACDC值下降，而PPG的DC值因强直刺激引起的血管收缩而增加（所有P<0.001）。AC、ACDC和DC值的最大变化在各部位之间无差异（P=无显著性差异）。脉搏率无显著变化（P=无显著性差异）。
结果表明，通过PPG测量，在这三个部位中的任何一个部位进行强直刺激都会产生相同的自主神经系统反应。
ClinicalTrials.gov；NCT03648853。
