Department of Respiratory Medicine, "G. Papanikolaou Hospital", Thessaloniki, Greece.
Exercise Physiology & Biochemistry Laboratory, Dept. of Sport Sciences at Serres, Aristotle University of Thessaloniki, Greece.
Respir Physiol Neurobiol. 2021 Aug;290:103677. doi: 10.1016/j.resp.2021.103677. Epub 2021 May 3.
The integrative physiological effects of O treatment on patients with pulmonary hypertension (PH) during exercise, have not been fully investigated. We simultaneously evaluated, for the first time, the effect of oxygen supplementation on hemodynamic responses, autonomic modulation, tissue oxygenation, and exercise performance in patients with pulmonary arterial hypertension (PAH)/Chronic Thromboembolic PH(CTEPH).
MATERIAL-METHODS: In this randomized, cross-over, placebo-controlled trial, stable outpatients with PAH/CTEPH underwent maximal cardiopulmonary exercise testing, followed by two submaximal trials, during which they received supplementary oxygen (O) or medical-air. Continuous, non-invasive hemodynamics were monitored via photophlythesmography. Cerebral and quadriceps muscle oxygenation were recorded via near-infrared spectroscopy. Autonomic function was assessed by heart rate variability; root mean square of successive differences (RMSSD) and standard-deviation-Poincare-plot (SD1) were used as indices of parasympathetic output. Baroreceptor sensitivity (BRS) was assessed throughout the protocols.
Nine patients (51.4 ± 9.4 years) were included. With O-supplementation patients exercised for longer (p = 0.01), maintained higher cerebral oxygenated hemoglobin (OHb;p = 0.02) levels, exhibited an amelioration in cortical deoxygenation (HHb;p = 0.02), and had higher average cardiac output (CO) during exercise (p < 0.05), compared to medical air; with no differences in muscle oxygenation. With O-supplementation patients exhibited higher BRS and sample-entropy throughout the protocol (p < 0.05) vs. medical air, and improved the blunted RMSSD, SD1 responses during exercise (p = 0.024).
We show that O administration improves BRS and autonomic function during submaximal exercise in PAH/CTEPH, without significantly affecting muscle oxygenation. The improved autonomic function, along with enhancements in cardiovascular function and cerebral oxygenation, probably contributes to increased exercise tolerance with O-supplementation in PH patients.
关于氧气治疗对运动期间肺动脉高压（PH）患者的综合生理影响，尚未进行充分研究。我们首次同时评估了氧气补充对肺动脉高压（PAH）/慢性血栓栓塞性 PH（CTEPH）患者血流动力学反应、自主神经调节、组织氧合和运动表现的影响。
在这项随机、交叉、安慰剂对照试验中，稳定的 PAH/CTEPH 门诊患者接受了最大心肺运动测试，随后进行了两次亚最大试验，在此期间他们接受了补充氧气（O）或医用空气。通过光容积描记术连续、非侵入性监测连续血流动力学。通过近红外光谱记录脑和股四头肌的氧合。通过心率变异性评估自主神经功能；使用均方根差（RMSSD）和 Poincaré 散点图标准差 1（SD1）作为副交感神经输出的指标。在整个方案中评估了压力感受器敏感性（BRS）。
纳入了 9 名患者（51.4±9.4 岁）。与医用空气相比，给予 O 补充的患者运动时间更长（p=0.01），运动期间保持更高的脑氧合血红蛋白（OHb）水平（p=0.02），大脑皮质去氧血红蛋白（HHb）改善（p=0.02），平均心输出量（CO）更高（p<0.05）；肌肉氧合没有差异。与医用空气相比，给予 O 补充的患者在整个方案中均表现出更高的 BRS 和样本熵（p<0.05），并改善了运动期间 RMSSD、SD1 反应迟钝（p=0.024）。
我们表明，在 PAH/CTEPH 患者的亚最大运动中，给予 O 可改善 BRS 和自主神经功能，而不会显著影响肌肉氧合。自主神经功能的改善，以及心血管功能和脑氧合的增强，可能有助于 PH 患者在 O 补充下提高运动耐力。
