Gass Ricardo, Merola Pietro, Monteiro Mariane B, Cardoso Dannuey M, Paiva Dulciane N, Teixeira Paulo Jz, Knorst Marli M, Berton Danilo C
Programa de Pós-Graduação em Ciências Pneumológicas, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul (UFRGS), Serviço de Pneumologia Hospital de Clínicas de Porto Alegre, Brazil.
Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA); Porto Alegre, Brazil.
Respir Care. 2017 Oct;62(10):1298-1306. doi: 10.4187/respcare.05556. Epub 2017 Aug 1.
The application of expiratory positive airway pressure (EPAP) in patients with COPD during exercise may reduce dynamic hyperinflation, while, on the other hand, it can increase the resistive work of breathing. Therefore, we evaluated the effects of 2 intensities of EPAP during exercise on tolerance, dynamic hyperinflation, and dyspnea in subjects with moderate to very severe COPD.
We performed a cross-sectional, experimental, 4-visit study. In visit 1, subjects performed symptom-limited cycling incremental cardiopulmonary exercise test (CPET). In visits 2-4, at least 48 h apart, in a randomized order, subjects performed constant CPET without EPAP, EPAP with 5 cm HO (EPAP5), or EPAP with 10 cm HO (EPAP10).
The study included 15 non-hypoxemic subjects ranging from moderate to very severe COPD (mean FEV = 35 ± 11% predicted). Increasing intensities of EPAP during constant CPET tended to cause progressive reduction in exercise tolerance ( = .11). Of note, 10 of 15 subjects demonstrated significantly shorter average exercise duration with EPAP10 compared to the test without EPAP (-151 ± 105 s, = .03 or -41 ± 26%). Minute ventilation increment was constrained by EPAP, secondary to a limited increase in tidal volume ( = .01). Finally, dyspnea sensation and serial measurements of inspiratory capacity during exercise were similar when comparing the three interventions at isotime and at end-constant CPETs.
The application of EPAP5 or EPAP10 during exercise tended to cause a progressive reduction in exercise tolerance in subjects with COPD without improvement in dyspnea or dynamic hyperinflation at equivalent exercise duration.
慢性阻塞性肺疾病（COPD）患者运动期间应用呼气末正压（EPAP）可减少动态肺过度充气，而另一方面，它会增加呼吸的阻力功。因此，我们评估了运动期间两种强度的EPAP对中度至极重度COPD患者的运动耐力、动态肺过度充气和呼吸困难的影响。
我们进行了一项横断面、实验性、4次访视的研究。在第1次访视中，受试者进行症状限制的递增式心肺运动试验（CPET）。在第2 - 4次访视中，间隔至少48小时，受试者按随机顺序进行无EPAP的持续CPET、5 cm H₂O的EPAP（EPAP5）或10 cm H₂O的EPAP（EPAP10）。
该研究纳入了15名非低氧血症患者，COPD程度从中度至极重度（平均FEV₁ = 预计值的35 ± 11%）。在持续CPET期间增加EPAP强度往往会导致运动耐力逐渐降低（P = 0.11）。值得注意的是，15名受试者中有10名显示，与无EPAP的测试相比，EPAP10时的平均运动持续时间显著缩短（-151 ± 105秒，P = 0.03或-41 ± 26%）。分钟通气量增加受到EPAP的限制，这是由于潮气量增加有限所致（P = .01）。最后，在等时间点和持续CPET结束时比较三种干预措施时，运动期间的呼吸困难感觉和吸气容量的系列测量结果相似。
运动期间应用EPAP5或EPAP10往往会导致COPD患者的运动耐力逐渐降低，在相同运动持续时间下，呼吸困难或动态肺过度充气并未改善。
