title: Effects of heated and humidified high flow gases during high-intensity constant-load exercise on severe COPD patients with ventilatory limitation.
abstract: High flow nasal cannula (HFNC) was shown to washout the anatomical dead space, permitting a higher fraction of minute ventilation to participate in gas pulmonary exchanges. Moreover, it is able to guarantee the desired inhaled oxygen fraction (FiO2) even at high level of patient's minute ventilation by minimizing the room air entrainment. The effect of HFNC has never been investigated on stable severe COPD patients in term of endurance capacity with standardised laboratory tests.
  
  
  
  We performed, in a randomized crossover study, two constant load exercise tests at the 75% of maximum workload achieved at a previous incremental exercise test on cycle-ergometer: with (HFNC-test) and without HFNC (Control-test). Both constant load tests were fulfilled at the same inhaled oxygen fraction (isoFiO2).
  
  
  
  The endurance time significantly increased in the HFNC-test compared to the Control-test (the mean difference between the two groups was 109 ± 104 s, p < 0.015). At iso-time, HFNC-test showed a better oxygen saturation (95 ± 3% vs 89 ± 3%, respectively, p < 0.005) either in the subgroup of patients who used supplemental oxygen and in the subgroup who did not. Moreover, a significantly lower dyspnea (median of 5.5 vs 10, respectively, p = 0.002) and leg fatigue score (median of 5 vs 9.5, p = 0.002) was recorded at iso-time during HFNC-test.
  
  
  
  HFNC may improve the exercise performance in severe COPD patients with ventilatory limitation. This effect is associated to an improvement of SaO2 and perceived symptoms at iso-time. In a Pulmonary Rehabilitation program HFNC may allow a given high intensity load to be sustained for a longer time with less symptoms.
authors: Pulmonary Rehabilitation Unit, IRCCS Fondazione S. Maugeri, Via Maugeri 10, Pavia, 27100, Italy.
authors: Serena
authors: S
authors: Cirio
authors: Pulmonary Rehabilitation Unit, IRCCS Fondazione S. Maugeri, Via Maugeri 10, Pavia, 27100, Italy.
authors: Manuela
authors: M
authors: Piran
authors: Pulmonary Rehabilitation Unit, IRCCS Fondazione S. Maugeri, Via Mazzini 129, Lumezzane, Brescia, 25066, Italy.
authors: Michele
authors: M
authors: Vitacca
authors: Pulmonary Rehabilitation Unit, IRCCS Fondazione S. Maugeri, Via Maugeri 10, Pavia, 27100, Italy.
authors: Giancarlo
authors: G
authors: Piaggi
authors: Pulmonary Rehabilitation Unit, IRCCS Fondazione S. Maugeri, Via Maugeri 10, Pavia, 27100, Italy.
authors: Piero
authors: P
authors: Ceriana
authors: Pulmonary Rehabilitation Unit, IRCCS Fondazione S. Maugeri, Via Maugeri 10, Pavia, 27100, Italy.
authors: Matteo
authors: M
authors: Prazzoli
authors: Pulmonary Rehabilitation Unit, IRCCS Fondazione S. Maugeri, Via Mazzini 129, Lumezzane, Brescia, 25066, Italy.
authors: Mara
authors: M
authors: Paneroni
authors: Pulmonary Rehabilitation Unit, IRCCS Fondazione S. Maugeri, Via Maugeri 10, Pavia, 27100, Italy. Electronic address: annalisa.carlucci@fsm.it.
authors: Annalisa
authors: A
authors: Carlucci
mesh_terms: D000368:Aged; D000072601:Cannula; D018592:Cross-Over Studies; D004417:Dyspnea / Q000628:therapy; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D063087:Noninvasive Ventilation / Q000295:instrumentation* / Q000379:methods; D010101:Oxygen Consumption / Q000502:physiology; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D010865:Pilot Projects; D029424:Pulmonary Disease, Chronic Obstructive / Q000628:therapy*; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012129:Respiratory Function Tests; D012131:Respiratory Insufficiency / Q000628:therapy
keywords: Chronic obstructive pulmonary disease; Chronic respiratory failure; Exercise training; High flow nasal cannula; Oxygen therapy