System and method of administering a pharmaceutical gas to a patient

1. A method of administering a pharmaceutical gas comprising nitric oxide to a patient, the method comprising:

delivering a first quantity of the pharmaceutical gas to the patient in a first breath;

monitoring the patient's respiratory rate or changes in the patient's respiratory rate in breaths per unit of time; and

varying the quantity of pharmaceutical gas delivered to the patient in one or more subsequent breaths based on the monitored respiratory rate or changes in the patient's respiratory rate, wherein one or more of:

the quantity delivered in the subsequent breath is greater than the first quantity in response to a decrease in the patient's respiratory rate; or

the quantity delivered in the subsequent breath is less than the first quantity in response to an increase in the patient's respiratory rate.

2. The method of claim 1 , wherein varying the quantity of pharmaceutical gas delivered to the patient avoids high unsafe doses or doses too low to be effective.

3. The method of claim 1 , wherein the pharmaceutical gas is delivered to the patient every breath.

4. The method of claim 1 , wherein one or more of the first quantity and the quantity delivered in the subsequent breath is delivered during the first half of inspiration.

5. A nitric oxide delivery system comprising:

an inlet to connect to a source of pharmaceutical gas comprising nitric oxide;

an outlet to connect to a device that introduces the pharmaceutical gas to a patient;

a breath trigger sensor to measure a patient's respiratory rate; and

a gas control system in communication with the breath trigger sensor that delivers a varying quantity of pharmaceutical gas to the patient based on changes in the patient's respiratory rate in breaths per unit of time, wherein one or more of:

the quantity delivered in a subsequent breath is greater than the quantity delivered in a previous breath in response to a decrease in the patient's respiratory rate; or

the quantity delivered in a subsequent breath is less than the quantity delivered in a previous breath in response to an increase in the patient's respiratory rate.

6. The system of claim 5 , wherein the gas control system delivers the quantity of pharmaceutical gas during the first half of the patient's inspiratory cycle.

7. The system of claim 5 , wherein the gas control system delivers the pharmaceutical gas to the patient every breath.

8. The system of claim 5 , wherein delivering a varying quantity of pharmaceutical gas to the patient avoids high unsafe doses or doses too low to be effective.

9. The method of claim 1 , wherein the unit of time is minute.

10. The system of claim 5 , wherein the unit of time is minute.