Our understanding of the mechanisms of dyspnoea in fibrotic interstitial lung disease (ILD) is incomplete. The aims of this study were two-fold: 1) to determine whether dyspnoea intensity is better predicted by neural respiratory drive (NRD) or neuromechanical uncoupling (NMU) of the respiratory system in fibrotic ILD, and 2) to examine the effect of breathing 60% oxygen on NRD, NMU and dyspnoea ratings. Fourteen patients with fibrotic ILD were included. Visit 1 comprised a familiarisation incremental cycle exercise test, Visit 2 comprised a normoxic incremental cycling test to address Aim 1, and Visits 3 and 4 consisted of constant-load cycling while breathing room air or 60% oxygen to address Aim 2. Diaphragmatic electromyography (EMGdi) was used as a surrogate of NRD. NMU was calculated as the ratio between EMGdi (%max) and tidal volume (%vital capacity). On adjusted analysis, NMU and its constituents were all significantly associated with dyspnoea ratings during incremental cycling, with EMGdi having the strongest correlation. The between-treatment change in dyspnoea ratings during constant load cycling was only correlated with change in exercise endurance time and NMU. Dyspnoea more strongly reflected the level of EMGdi than NMU in fibrotic ILD. However, the improvement in dyspnoea with 60% oxygen was better predicted by improvements in NMU. Neural respiratory drive is a strong independent predictor of dyspnoea in patients with fibrotic ILD http://ow.ly/MXjd30hcabH

中文翻译：

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纤维化间质性肺病劳力性呼吸困难的神经生理机制

我们对纤维化间质性肺病 (ILD) 中呼吸困难的机制的理解是不完整的。本研究的目的有两个：1) 确定是否通过神经呼吸驱动 (NRD) 或呼吸系统的神经机械解耦 (NMU) 来更好地预测纤维化 ILD 中呼吸困难的强度，以及 2) 检查呼吸的影响NRD、NMU 和呼吸困难评级为 60% 氧气。包括 14 名纤维化 ILD 患者。访问 1 包括熟悉增量循环运动测试，访问 2 包括常氧增量循环测试以解决目标 1，访问 3 和 4 包括恒定负荷循环，同时呼吸室内空气或 60% 氧气以解决目标 2。 EMGdi) 被用作 NRD 的替代品。NMU 计算为 EMGdi (%max) 和潮气量 (%肺活量) 之间的比率。在调整后的分析中，NMU 及其成分都与渐进循环期间的呼吸困难等级显着相关，其中 EMGdi 具有最强的相关性。恒定负荷循环期间呼吸困难等级的治疗间变化仅与运动耐力时间和 NMU 的变化相关。在纤维化 ILD 中，呼吸困难比 NMU 更强烈地反映了 EMGdi 的水平。然而，通过 NMU 的改善可以更好地预测 60% 氧气对呼吸困难的改善。神经呼吸驱动是纤维化 ILD 患者呼吸困难的强有力的独立预测因素 http://ow.ly/MXjd30hcabH EMGdi 具有最强的相关性。恒定负荷循环期间呼吸困难等级的治疗间变化仅与运动耐力时间和 NMU 的变化相关。在纤维化 ILD 中，呼吸困难比 NMU 更强烈地反映了 EMGdi 的水平。然而，通过 NMU 的改善可以更好地预测 60% 氧气对呼吸困难的改善。神经呼吸驱动是纤维化 ILD 患者呼吸困难的强有力的独立预测因素 http://ow.ly/MXjd30hcabH EMGdi 具有最强的相关性。恒定负荷循环期间呼吸困难等级的治疗间变化仅与运动耐力时间和 NMU 的变化相关。在纤维化 ILD 中，呼吸困难比 NMU 更强烈地反映了 EMGdi 的水平。然而，通过 NMU 的改善可以更好地预测 60% 氧气对呼吸困难的改善。神经呼吸驱动是纤维化 ILD 患者呼吸困难的强有力的独立预测因素 http://ow.ly/MXjd30hcabH