LOW-LEVELS OF NITRIC-OXIDE AS CONTAMINANT IN-HOSPITAL COMPRESSED-AIR - PHYSIOLOGICAL SIGNIFICANCE

Objectives: To determine whether the levels of nitric oxide found in h ospital compressed air have a clinically relevant effect on oxygenatio n in intubated patients with normal lungs, Design: Prospective study, Setting: Cardiothoracic and surgical intensive care unit in a universi ty hospital, Patients: Twelve postoperative patients receiving mechani cal ventilation, Interventions: Pure nitrogen and oxygen were substitu ted for hospital compressed air as a source of blending for correct FI O2. Measurements and Main Results: Hemodynamics and Pao(2) were measur ed in nitrogen and oxygen used for blending oxygen during stable FIO2 levels, Inhaled nitric oxide was measured with a nitric oxide-chemilum inescence detector. There was no clinically relevant change in systemi c hemodynamics, However, the Pao(2) decreased significantly when nitro gen was used for blending, Inhaled nitric oxide levels varied from 2 t o 550 parts per billion during use of hospital compressed air; no nitr ic oxide was detectable during use of nitrogen, Conclusions: The low c oncentration of nitric oxide in hospital compressed air improves oxyge nation in patients with normal lungs receiving mechanical ventilation.