In one aspect, a system for delivering nitric oxide to a patient can include a first gas source including nitrogen dioxide mixed in air or oxygen, a second gas source supplying compressed air, a ventilator coupled to the first and second gas sources, where the ventilator can be resistant to nitrogen dioxide, and where the ventilator provides a gas flow having a proper amount of nitrogen dioxide, one or more conversion devices operably coupled to the ventilator, where the conversion devices covert nitrogen dioxide into nitric oxide, and a patient interface operably coupled to the conversion devices, where the patient interface delivers nitric oxide to the patient.