Richter M J, Voswinkel R, Tiede H, Seeger W, Schulz R, Ghofrani H A, Reichenberger F
Abteilung für allgemeine Pneumologie, Kerckhoff-Klinik Bad Nauheim, Bad Nauheim, Germany.
Pneumologie. 2013 May;67(5):280-7. doi: 10.1055/s-0033-1343148. Epub 2013 May 15.
The dynamic decrease in inspiratory capacity (IC) during exercise with restriction of tidal volume (VT) is known as dynamic hyperinflation (DH) and is described mostly in patients with COPD differentiating between a "hyperinflator" and a "non-hyperinflator". Recent studies have revealed DH in patients with idiopathic pulmonary arterial hypertension (iPAH), but the influence of the DH on the reduced exercise capacity with exertional dyspnoae is still being debated.
We analysed flow-volume curves during cardiopulmonary exercise testing (CPET) in idiopathic PAH (n = 19), in COPD (n = 17), in idiopathic pulmonary fibrosis (IPF) (n = 19) and a control group (n = 30). We measured IC at rest and during maximal exercise and furthermore ventilation, VT and oxygen uptake (VO2 peak). In iPAH a right heart catheter test and a 6-minute walk test (6MWT) were performed, also the B-type naturetic peptide (BNP) and the NYHA/WHO functional class were determined.
The IC decreased significantly in 11 PAH "hyperinflators" (PAH-H) (Δ IC: - 0.34 ± 0.14 L, p < 0.001) compared to 8 PAH "non-hyperinflators" (PAH-NH) (Δ IC: 0.08 ± 0.2 L). COPD patients exhibited a characteristic hyperinflation pattern with a decrease in IC throughout exercise (Δ IC: - 0.61 ± 0.3 L, p < 0.001), while patients with IPF (Δ IC: 0.03 ± 0.15 L) and the control group responsed to exercise with a non-hyperinflator pattern (Δ IC: 0.1 ± 0.2 L). Both PAH collectives showed a reduced IC/TLC, while VT/IC was elevated with a decreased peak VO2 and max. performance compared to the control group. Correlations of the IC rest/max (L) were shown in PAH-H and PAH-NH with the VO2 peak, max. performance and VT.
The analysis of flow-volume curves during CPET can indentify DH in a subgroup of patients with iPAH. The DH contributes significantly but slightly to the development of exertional limitations and dyspnoe in a subgroup of iPAH. Further studies with a larger sample size will be required to definitively measure the impact of the DH seen in these patients.
运动期间吸气容量（IC）随潮气量（VT）受限而动态下降被称为动态肺过度充气（DH），主要在慢性阻塞性肺疾病（COPD）患者中描述，可区分“肺过度充气者”和“非肺过度充气者”。最近的研究揭示了特发性肺动脉高压（iPAH）患者中存在DH，但DH对运动能力下降伴劳力性呼吸困难的影响仍存在争议。
我们分析了特发性PAH（n = 19）、COPD（n = 17）、特发性肺纤维化（IPF）（n = 19）患者及对照组（n = 30）在心肺运动试验（CPET）期间的流量-容积曲线。我们测量了静息和最大运动时的IC，以及通气、VT和摄氧量（VO2峰值）。在iPAH患者中进行了右心导管检查和6分钟步行试验（6MWT），还测定了B型利钠肽（BNP）和纽约心脏协会/世界卫生组织功能分级。
与8例PAH“非肺过度充气者”（PAH-NH）（ΔIC：0.08±0.2L）相比，11例PAH“肺过度充气者”（PAH-H）的IC显著下降（ΔIC：-0.34±0.14L，p<0.001）。COPD患者表现出典型的肺过度充气模式，运动过程中IC下降（ΔIC：-0.61±0.3L，p<0.001），而IPF患者（ΔIC：0.03±0.15L）和对照组以非肺过度充气模式对运动作出反应（ΔIC：0.1±0.2L）。两个PAH组均显示IC/TLC降低，而与对照组相比，VT/IC升高，VO2峰值和最大运动能力降低。PAH-H和PAH-NH中IC静息/最大值（L）与VO2峰值、最大运动能力和VT之间存在相关性。
CPET期间流量-容积曲线分析可识别iPAH患者亚组中的DH。DH在iPAH患者亚组中对劳力性受限和呼吸困难的发展有显著但轻微的影响。需要进行更大样本量的进一步研究来明确测量这些患者中所见DH的影响。
