Delivery of high concentration nitric oxide

1. A method, comprising:

repeatedly delivering, for periods of at least two breaths, between 1000 ppm and 2000 ppm of nitric oxide to a mammal; and

delivering, between each period, at least one breath of oxygen-enriched air to the mammal.

2. The method of claim 1 , further comprising delivering one or more breaths of the oxygen-enriched air to the mammal before delivering the at least two breaths of nitric oxide to the mammal.

3. The method of claim 1 , wherein:

one breath of the oxygen-enriched air is delivered between each period.

4. The method of claim 1 , wherein:

each period of delivery of nitric oxide has a duration of two breaths; and

two breaths of the oxygen-enriched air are delivered between each period.

5. The method of claim 1 , further comprising generating the nitric oxide by exposing nitrogen dioxide to an antioxidant.

6. The method of claim 5 , wherein the antioxidant is at least one of ascorbic acid, alpha tocopherol, or gamma tocopherol.

7. The method of claim 5 , wherein the nitric oxide is delivered to the mammal via a tube that includes the antioxidant.

8. The method of claim 7 , wherein the antioxidant is at least one of ascorbic acid, alpha tocopherol, or gamma tocopherol.

9. The method of claim 1 , wherein the balance of the between 1000 ppm and 2000 ppm of nitric oxide is air.

10. The method of claim 1 , wherein oxygen enriched air contains at least 21% oxygen.

11. The method of claim 1 , wherein:

the nitric oxide is delivered to the mammal via a first tube; and

the oxygen-enriched air is delivered to the mammal via a second tube different from the first tube.