Conversion of nitrogen dioxide (NO
Inhalation of low levels of nitric oxide can rapidly and safely decrease pulmonary hypertension in mammals. A nitric oxide delivery system that converts nitrogen dioxide to nitric oxide employs a surface-active material, such as silica gel, coated with an aqueous solution of antioxidant, such as ascorbic acid.
1. A method, comprising:
conveying a nitrogen dioxide-containing gas from a tankless gas source that contains dinitrogen tetroxide to a cartridge; and
passing the nitrogen dioxide-containing gas through the cartridge to remove the nitrogen dioxide, producing a nitric oxide-containing gas.
2. The method of claim 1 , wherein the cartridge includes a reducing agent configured to react with nitrogen dioxide to produce nitric oxide.
3. The method of claim 1 , wherein the cartridge includes a substrate coated with a reducing agent, the method further comprises:
flowing the nitrogen dioxide-containing gas over the substrate such that the reducing agent converts nitrogen dioxide in the nitrogen dioxide-containing gas to nitric oxide.
4. The method of claim 2 , further comprising delivering the nitric oxide-containing gas to a patient.
5. The method of claim 3 , further comprising delivering the nitric oxide-containing gas to a patient.
6. The method of claim 1 , further comprising delivering the nitric oxide-containing gas to a patient.
7. A method, comprising:
conveying a nitrogen dioxide-containing gas to a cartridge; and
passing the nitrogen dioxide-containing gas through the cartridge, the cartridge including at least one of vitamin C or vitamin E configured to react with nitrogen dioxide to remove the nitrogen dioxide and produce a nitric oxide-containing gas.
8. The method of claim 7 , further comprising delivering the nitric oxide-containing gas to a patient.
9. A method, comprising:
conveying a nitrogen dioxide-containing gas to a cartridge; and
passing the nitrogen dioxide-containing gas through the cartridge, the cartridge including silica gel wetted with ascorbic acid such that the nitrogen dioxide-containing gas flows over the silica gel and such that the ascorbic acid reacts with nitrogen dioxide to produce a nitric oxide-containing gas.
10. The method of claim 9 , wherein:
the silica gel is porous and has a mesh size between 35 and 70.
11. The method of claim 9 , further comprising delivering the nitric oxide-containing gas to a patient.
12. The method of claim 10 , further comprising delivering the nitric oxide-containing gas to a patient.
13. A method, comprising:
conveying a nitrogen dioxide-containing gas to a cartridge;
passing the nitrogen dioxide-containing gas through the cartridge to remove the nitrogen dioxide, producing a nitric oxide-containing gas;
mixing the nitric oxide-containing gas with an oxygen-containing gas; and
delivering the nitric oxide-containing gas to a patient after mixing the nitric oxide-containing gas and the oxygen-containing gas.
14. The method of claim 13 , wherein the nitric oxide-containing gas is supplied to a ventilator prior to being delivered to the patient.
15. The method of claim 13 , further comprising delivering the nitric oxide-containing gas to a flexible bag prior to delivering the nitric-oxide containing gas to the patient such that a constant supply of nitric oxide can be delivered to the patient during inhalation.
16. The method of claim 13 , wherein the nitric oxide is delivered to the patient to treat pulmonary hypertension.
17. The method of claim 13 , wherein the patient is a newborn and the nitric oxide is delivered to treat persistent pulmonary hypertension.
18. The method of claim 13 , wherein the nitric oxide is delivered to the patient to treat bronchopulmonary dysplasia.
19. The method of claim 13 , wherein the patient is a cardiac surgery patient.
20. A method, comprising:
conveying a nitrogen dioxide-containing gas from an unpressurized tankless gas source to a cartridge; and
passing the nitrogen dioxide-containing gas through the cartridge to remove the nitrogen dioxide, producing a nitric oxide-containing gas.
21. The method of claim 20 , further comprising delivering the nitric oxide-containing gas to a patient.
22. A method, comprising:
conveying a nitrogen dioxide-containing gas to a cartridge;
passing the nitrogen dioxide-containing gas through the cartridge to remove the nitrogen dioxide, producing a nitric oxide-containing gas;
measuring a concentration of nitrogen dioxide in the nitric oxide-containing gas before the nitric oxide-containing gas is delivered to a patient; and
generating an alarm when a concentration of nitrogen dioxide in the nitric-oxide containing gas exceeds a threshold.
23. A method, comprising:
conveying a nitrogen dioxide-containing gas to a cartridge; and
passing the nitrogen dioxide-containing gas through the cartridge, the cartridge including a nontoxic reducing agent configured to react with nitrogen dioxide to produce a nitric oxide-containing gas.
24. The method of claim 23 , further comprising delivering the nitric oxide-containing gas to a patient.
25. A method, comprising:
conveying a nitrogen dioxide-containing gas to a cartridge; and
passing the nitrogen dioxide-containing gas through the cartridge, the cartridge including a reducing agent configured to react with nitrogen dioxide to produce nitric oxide, removing all nitrogen dioxide from nitrogen dioxide-containing gas and producing a nitric oxide-containing gas.
26. The method of claim 25 , further comprising delivering the nitric oxide-containing gas to a patient.