Hemodynamic effects of inhaled nitric oxide using pulse delivery and continuous delivery systems in pulmonary hypertension.
OBJECTIVE
Inhaled nitric oxide (NO) has been used for pulmonary vasodilation therapy in patients with pulmonary hypertension. Inhaled NO for awake and ambulatory patients, however, is unusual because it requires intubation or a tightly fitting facemask, and a large-scale delivery system for the safe management of toxic nitrogen oxides. We undertook this study to investigate the possibility of using inhaled NO therapy for awake and ambulatory patients with pulmonary hypertension.


METHODS
Patients with pulmonary hypertension underwent cardiac catheterization and hemodynamic variables were measured at the baseline, after inhaled NO using our pulse delivery system, which involved a nasal cannula and a pulse device, and after inhaled NO using a continuous delivery system.


METHODS
We studied seventeen patients with precapillary pulmonary hypertension (4 men and 13 women; age, 41+/-3, ranging from 19 to 61).


RESULTS
Cardiac output was increased significantly by each system. Pulmonary vascular resistance was decreased significantly by each system. There was no significant change in mean pulmonary artery pressure, mean systemic artery pressure, or systemic vascular resistance. The concentrations of NO and nitrogen dioxide (NO2) in the expiratory gas using the pulse delivery system were 0.0 ppm as long as the pulse device was synchronized with the patient's respiratory cycle.


CONCLUSIONS
Inhaled NO using our pulse delivery system changed the hemodynamic variables similarly to those when using the continuous delivery system. The concentrations of NO and NO2 in the expiratory gas using the pulse delivery system were within safe limits.
Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai.
Osamu
O
Kitamukai
Masahito
M
Sakuma
Tohru
T
Takahashi
Jun
J
Nawata
Jun
J
Ikeda
Kunio
K
Shirato
D000280:Administration, Inhalation; D000328:Adult; D006328:Cardiac Catheterization; D002302:Cardiac Output / Q000187:drug effects; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy*; D008168:Lung / Q000187:drug effects / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D009569:Nitric Oxide / Q000008:administration & dosage*; D011651:Pulmonary Artery / Q000187:drug effects; D012449:Safety; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage*
D014665:Vasodilator Agents; D009569:Nitric Oxide