-transparent.png){kind=logo}
Patients with chronic obstructive pulmonary disease (COPD) may develop hypoxemia and pulmonary hypertension when exercising. To investigate whether inhaled nitric oxide (NO), a selective pulmonary vasodilator, modifies the changes induced by exercise in pulmonary hemodynamics and gas exchange in COPD, we studied nine patients (FEV1, = 39 +/- 2% predicted), at rest and at submaximal exercise, during breathing of room air and NO (40 ppm). NO inhalation decreased pulmonary artery pressure (Ppa) both at rest and during exercise (analysis of variance [ANOVA] p < 0.05). However, the effect of NO on PaO2 was different at rest than during exercise. At rest, NO decreased PaO2 from 72 +/- 3 mm Hg to 65 +/- 2 mm Hg, due to an increase in ventilation-perfusion (VA/Q) inequality (dispersion of blood flow distribution from 0.9 +/- 0.1 to 1.1 +/- 0.1). During exercise, PaO2 decreased during breathing of room air (-5 +/- 3 mm Hg), whereas it remained essentially unchanged during inhalation of NO (+2 +/- 3 mm Hg), with both changes being significantly different (p < 0.05). VA/Q relationships improved during exercise during breathing of both room air and NO, as a result of a reduction in the dispersion of ventilation distribution. Moreover, NO administered on exertion contributed to redistribute blood flow from alveolar units with low VA/Q ratios to units with normal ratios (p < 0.05). We conclude that in patients with COPD, the inhalation of NO during exercise moderately reduces pulmonary hypertension, and that in contrast with the effects of such inhalation at rest, it may prevent the exercise-associated decrease of PaO2. This effect is probably explained by a preferential distribution of inhaled NO during exercise to well-ventilated alveolar units with faster time constants and normal VA/Q ratios.
N Roger, and
J A Barberà, and
J Roca, and
I Rovira, and
F P Gómez, and
R Rodriguez-Roisin
February 2000,
Thorax,
N Roger, and
J A Barberà, and
J Roca, and
I Rovira, and
F P Gómez, and
R Rodriguez-Roisin
February 1997,
American journal of respiratory and critical care medicine,
N Roger, and
J A Barberà, and
J Roca, and
I Rovira, and
F P Gómez, and
R Rodriguez-Roisin
December 1996,
Monaldi archives for chest disease = Archivio Monaldi per le malattie del torace,
N Roger, and
J A Barberà, and
J Roca, and
I Rovira, and
F P Gómez, and
R Rodriguez-Roisin
January 1997,
Nihon Kyobu Shikkan Gakkai zasshi,
N Roger, and
J A Barberà, and
J Roca, and
I Rovira, and
F P Gómez, and
R Rodriguez-Roisin
October 1997,
American heart journal,
N Roger, and
J A Barberà, and
J Roca, and
I Rovira, and
F P Gómez, and
R Rodriguez-Roisin
March 1998,
American journal of respiratory and critical care medicine,
N Roger, and
J A Barberà, and
J Roca, and
I Rovira, and
F P Gómez, and
R Rodriguez-Roisin
April 2009,
Annals of thoracic medicine,
N Roger, and
J A Barberà, and
J Roca, and
I Rovira, and
F P Gómez, and
R Rodriguez-Roisin
March 2003,
Current allergy and asthma reports,
N Roger, and
J A Barberà, and
J Roca, and
I Rovira, and
F P Gómez, and
R Rodriguez-Roisin
March 2015,
Journal of thoracic disease,
N Roger, and
J A Barberà, and
J Roca, and
I Rovira, and
F P Gómez, and
R Rodriguez-Roisin
December 2012,
Journal of breath research,
