Currens Joshua B, Moon Richard E, Makowski Matthew S, Natoli Michael J, Leypoldt Jayne, Woolard Jean, Brown David, Azarang Arian, Brown Robert, Schinazi Eric, Ransom Zach, Papadopoulou Virginie, Lance Rachel M
Department of Anesthesiology, Duke Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, North Carolina, United States.
Department of Radiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States.
J Appl Physiol (1985). 2025 Aug 1;139(2):365-375. doi: 10.1152/japplphysiol.00171.2025. Epub 2025 Jun 30.
Ultrasound is currently the optimal imaging modality in the decompression research field for assessing intracorporeal gas. Decompression sickness (DCS) is triggered by excess gas bubble presence in the body; however, the relationship is not well understood. Presently, the decompression physiology field does not have a strong predictive DCS biomarker. In this study, we explore the presence of lymph node decompression bubbles in a porcine model after a provocative hyperbaric exposure. Porcine test subjects ( = 37 subjects) underwent an aggressive decompression profile as part of a larger study, and a subsequent investigation of the left inguinal lymph node was conducted with ultrasound. Ultrasound images were assessed by three trained sonographers for lymph node bubbles. Regional brightness was analyzed after post hoc phantom-calibrated standardization of ultrasound depth and gain settings. Out of the 37 animals that we examined for lymph node bubbles, 17 were diagnosed with severe DCS and 14 identified to have lymph node bubbles. A postmortem dissection was conducted for a few animals, and bubbles could be found streaming from the lymph node corresponding to a severe DCS subject. The brightness assessment of the standardized ultrasound images indicated that DCS cases typically had a decrease in the region intensity after the dive with a potential peak sensitivity of 94.1% and specificity of 55% based on receiver-operating curve analysis. This study is the first noninvasive detection of lymph node decompression bubbles with confirmation of bubbles by postmortem dissection. A positive correlation between lymph node bubbles and DCS severity was found. This is the first ever study to noninvasively detect lymphatic decompression bubbles and examine their correspondence with severe decompression sickness (DCS) outcome. The image brightness analysis found that subjects with severe DCS were likely to have darker lymph node images postdive indicating potential gas presence, after variable ultrasound system settings were unified post hoc. These findings may provide an early framework for a wearable ultrasound device to monitor real-time decompression stress.
超声目前是减压研究领域中评估体内气体的最佳成像方式。减压病（DCS）是由体内过量气泡的存在引发的；然而，两者之间的关系尚未完全明晰。目前，减压生理学领域尚无强大的预测DCS生物标志物。在本研究中，我们在猪模型中进行了激发性高压暴露后，探究腹股沟淋巴结减压气泡的存在情况。作为一项更大规模研究的一部分，猪实验对象（n = 37只）经历了激进的减压过程，随后用超声对左腹股沟淋巴结进行了检查。三名经过培训的超声医师对超声图像进行评估以查找淋巴结气泡。在对超声深度和增益设置进行事后体模校准标准化后，分析区域亮度。在我们检查的37只存在淋巴结气泡的动物中，17只被诊断为重度DCS，14只被确定有淋巴结气泡。对几只动物进行了尸检，在一只对应重度DCS的动物的淋巴结中发现有气泡流出。标准化超声图像的亮度评估表明，根据受试者工作特征曲线分析，DCS病例在潜水后区域强度通常会降低，潜在峰值灵敏度为94.1%，特异性为55%。本研究首次通过尸检确认气泡，对淋巴结减压气泡进行了无创检测。发现淋巴结气泡与DCS严重程度呈正相关。这是首次对淋巴减压气泡进行无创检测并研究其与重度减压病（DCS）结果的对应关系。图像亮度分析发现，在事后统一可变超声系统设置后，重度DCS受试者潜水后淋巴结图像可能较暗，表明可能存在气体。这些发现可能为可穿戴超声设备监测实时减压压力提供早期框架。
