Abstract:

Objective To evaluate the clinical effects of inhaled nitric oxide (NO) on patients with refractory hypoxemia after open heart surgery. Methods The patients in ICU with stable circulation but their PaO2/FiO2 (arterial oxygen tension/fraction of inspired oxygen) <100 mmHg （1 mmHg=0.133 kPa） over 4 h after cardiac surgery were given NO treatment. The concentration of inhaled NO was 5-10 ppm. Values of oxygenation and circulation index before, 1 h after, and 24 h after NO treatment were compared for 17 patients. Results Among 17 patients, 6 died and 11 were cured. After NO was inhaled for 1 h，PaO2/FiO2 improved significantly [(105.1±22.1) mmHg vs (77.9±15.6) mmHg](P<0.01), and further improved after 24 h [(141.1±50.6) mmHg vs (105.1±22.1) mmHg](P<0.05), during which heart rate, mean arterial pressure, and dopamine dose remained unchanged except that after 24 h the heart rate decreased [(85.1±14.5)/min vs (96.2±22.4)/min](P<0.05). There were no side effects relevant to inhaling NO. Conclusion For patients with refractory hypoxemia after cardiac surgery, inhaling NO can improve PaO2/FiO2 without causing side effects on hemodynamics.

Key words: nitric oxide, open heart surgery, hypoxemia