Camila Melo Coelho Loureiro, Eloara V M Ferreira, Rudolf K F Oliveira, Andrei Augusto Assis de Campos Cordeiro, Elaine Brito Vieira, Meliane de Oliveira Daud, Ivan Teruaki Ivanaga, Luiz Eduardo Nery, Jaquelina Sonoe Ota-Arakaki, Roberta Pulcheri Ramos
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引用次数: 0
Abstract
Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is mainly caused by mechanical obstruction by thrombi associated with pulmonary vascular remodeling. Bronchial collateral circulation has been studied as a protective mechanism or implicated in the pathogenesis of microvascular disease, also contributing to changes in gas exchange at rest and during exercise. In this study, we sought to characterize the gas exchange abnormalities in patients with CTEPH with particular attention to bronchopulmonary shunt.
Methods: Prospective, cross-sectional study with diagnostic intervention. After undergoing right heart catheterization, subjects performed a 50% maximal workload steady-state exercise at room air and receiving 100% oxygen with a face mask from a Douglas bag. Arterial and mixed venous blood samples were obtained for gas analysis and calculation of shunt.
Results: Data from 14 subjects (7 women, 49 ± 15 years) with CTEPH were analyzed. All participants showed an increased shunt volume/fraction detected by 100% oxygen breathing at rest that decreased during exercise (17.0 ± 3.6% versus 9.8 ± 3.0%; P<0.001). Shunt fraction was negatively correlated with hemodynamic severity at rest, degree of pulmonary vascular obstruction and dilation of the pulmonary artery trunk. A drop in PaO₂ was observed in 71% of patients with RVP > 750 dynes.s.cm5, compared to 14% among those with less severe hemodynamic profile. Multiple linear regression analysis revealed that both PVR and the Qanadli score were independently associated with bronchopulmonary shunt fraction during exercise.
Conclusion: Bronchopulmonary shunt seems to be an adaptive mechanism in CTEPH at rest and during exercise.
背景:慢性血栓栓塞性肺动脉高压(CTEPH)主要由与肺血管重构相关的血栓机械性阻塞引起。支气管侧枝循环作为一种保护机制或参与微血管疾病的发病机制,也有助于休息和运动时气体交换的变化。在这项研究中,我们试图描述CTEPH患者的气体交换异常,特别关注支气管肺分流。方法:前瞻性、横断面研究和诊断干预。在接受右心导管插管后,受试者在室内空气中进行50%最大负荷稳态运动,并在道格拉斯袋面罩下接受100%氧气。取动脉血和混合性静脉血进行气体分析和分流计算。结果:分析了14例CTEPH患者(7例女性,49±15岁)的数据。所有参与者在休息时100%氧气呼吸检测到的分流体积/分数增加,在运动期间下降(17.0±3.6% vs 9.8±3.0%;P 750 dydys)。而在血流动力学不太严重的患者中,这一比例为14%。多元线性回归分析显示PVR和Qanadli评分与运动时支气管肺分流分数独立相关。结论:支气管肺分流可能是静止和运动时CTEPH的一种适应性机制。
期刊介绍:
Respiratory Physiology & Neurobiology (RESPNB) publishes original articles and invited reviews concerning physiology and pathophysiology of respiration in its broadest sense.
Although a special focus is on topics in neurobiology, high quality papers in respiratory molecular and cellular biology are also welcome, as are high-quality papers in traditional areas, such as:
-Mechanics of breathing-
Gas exchange and acid-base balance-
Respiration at rest and exercise-
Respiration in unusual conditions, like high or low pressure or changes of temperature, low ambient oxygen-
Embryonic and adult respiration-
Comparative respiratory physiology.
Papers on clinical aspects, original methods, as well as theoretical papers are also considered as long as they foster the understanding of respiratory physiology and pathophysiology.