Saxer Stéphanie, Calendo Luigi-Riccardo, Lichtblau Mona, Carta Arcangelo, Müller Julian, Gautschi Fiorenza, Berlier Charlotte, Furian Michael, Schwarz Esther I, Bloch Konrad E, Greutmann Matthias, Ulrich Silvia
Clinic of Pulmonology, University Hospital of Zurich, Switzerland.
Clinic of Pulmonology, University Hospital of Zurich, Switzerland; Zurich University of Applied Sciences, ZHAW, Institute of Physiotherapy, Winterthur, Switzerland.
Int J Cardiol. 2022 Feb 1;348:65-72. doi: 10.1016/j.ijcard.2021.11.066. Epub 2021 Nov 30.
Patients with unrepaired cyanotic congenital heart disease (CHD) suffer from aggravated hypoxemia during exercise. We tested the hypothesis that supplemental oxygen improves exercise performance in these patients.
In this randomized, sham-controlled, single-blind, cross-over trial cyanotic CHD-patients underwent four cycle exercise tests to exhaustion, while breathing either oxygen-enriched (FiO 0.50, oxygen) or ambient air (FiO 0.21, air) using incremental (IET) or constant work-rate (CWRET) exercise test protocols (75% of maximal work rate achieved under FiO 0.21). Pulmonary gas-exchange, electrocardiogram, arterial blood gases, oxygen saturation (SpO), cerebral and quadriceps muscle tissue oxygenation (CTO and QMTO) by near-infrared spectroscopy were measured.
We included seven patients with cyanotic CHD (4 Eisenmenger syndrome, 3 unrepaired cyanotic defects, 4 women) median (quartiles) age 36 (32;50) years, BMI 23 (20;26) kg/m and SpO at rest 87 (83;89) %. When comparing supplemental oxygen with air during exercise, maximal work-rate in IET increased from 76 (58;114) Watts to 83 (67;136) Watts, median difference 9 (0;22) W (p = 0.046) and CWRET-time increased from 412 s (325;490) to 468 s (415;553), median increase 56 (39;126) s (p = 0.018). In both IET and CWRET SpO was significantly higher and ventilatory equivalent for carbon dioxide significantly lower at end-exercise with oxygen compared to air, whereas CTO and QMTO did not significantly differ.
Patients with cyanotic CHD significantly improved their exercise performance, in terms of maximal work-rate and endurance time along with an improved arterial oxygenation and ventilatory efficiency with supplemental oxygen compared to air.
患有未修复的青紫型先天性心脏病（CHD）的患者在运动期间会出现缺氧加重的情况。我们检验了补充氧气可改善这些患者运动表现的假设。
在这项随机、假对照、单盲、交叉试验中，青紫型CHD患者接受了4次运动测试直至力竭，分别使用递增运动测试方案（IET）或恒定工作率运动测试方案（CWRET）（达到FiO₂ 0.21时最大工作率的75%），期间呼吸富氧空气（FiO₂ 0.50，氧气）或环境空气（FiO₂ 0.21，空气）。测量了肺气体交换、心电图、动脉血气、氧饱和度（SpO₂），以及通过近红外光谱测量的脑和股四头肌组织氧合（CTO和QMTO）。
我们纳入了7例青紫型CHD患者（4例艾森曼格综合征、3例未修复的青紫型缺陷，4例女性），年龄中位数（四分位数间距）为36（32；50）岁，体重指数为23（20；26）kg/m²，静息SpO₂为87（83；89）%。在运动期间将补充氧气与空气进行比较时，IET中的最大工作率从76（58；114）瓦增加到83（67；136）瓦，中位数差异为9（0；22）瓦（p = 0.046），CWRET时间从412秒（325；490）增加到468秒（415；553），中位数增加56（39；126）秒（p = 0.018）。在IET和CWRET中，与空气相比，运动结束时使用氧气时SpO₂显著更高，二氧化碳通气当量显著更低，而CTO和QMTO无显著差异。
与空气相比，补充氧气后，青紫型CHD患者在最大工作率和耐力时间方面的运动表现显著改善，同时动脉氧合和通气效率也有所提高。
