Low levels of nitric oxide as contaminant in hospital compressed air: physiologic significance?
OBJECTIVE
To determine whether the levels of nitric oxide found in hospital compressed air have a clinically relevant effect on oxygenation in intubated patients with normal lungs.


METHODS
Prospective study.


METHODS
Cardiothoracic and surgical intensive care unit in a university hospital.


METHODS
Twelve postoperative patients receiving mechanical ventilation.


METHODS
Pure nitrogen and oxygen were substituted for hospital compressed air as a source of blending for correct FIO2.


RESULTS
Hemodynamics and PaO2 were measured in nitrogen and oxygen used for blending oxygen during stable FIO2 levels. Inhaled nitric oxide was measured with a nitric oxide-chemiluminescence detector. There was no clinically relevant change in systemic hemodynamics. However, the PaO2 decreased significantly when nitrogen was used for blending. Inhaled nitric oxide levels varied from 2 to 550 parts per billion during use of hospital compressed air; no nitric oxide was detectable during use of nitrogen.


CONCLUSIONS
The low concentration of nitric oxide in hospital compressed air improves oxygenation in patients with normal lungs receiving mechanical ventilation.
Lee
K H
KH
Department of Anesthesiology/Critical Care Medicine, University of Pittsburgh Medical Center, PA 15261, USA.
Tan
P S
PS
Rico
P
P
Delgado
E
E
Kellum
J A
JA
Pinsky
M R
MR
D001784:Blood Gas Analysis; D003422:Critical Care; D004780:Environment, Controlled; D006439:Hemodynamics; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D008176:Lung Volume Measurements; D009569:Nitric Oxide; D009584:Nitrogen; D010100:Oxygen; D011446:Prospective Studies; D012121:Respiration, Artificial
D009569:Nitric Oxide; D009584:Nitrogen; D010100:Oxygen