AN APPRAISAL OF TECHNIQUES FOR ADMINISTRATION OF GASEOUS NITRIC-OXIDE

Gaseous nitric oxide (NO) is a potent selective pulmonary vasodilator When mixed with O2 for more than 10-15 minutes it forms toxic amounts of nitrogen dioxide (NO2). We describe two techniques to administer 20 parts per million (ppm) during mechanical ventilation. A technique us ing flows of NO and 02 at low pressure to drive a Siemens Servo 900C v entilator provided a constant inspired concentration of NO. Another te chnique in which NO was added to the inspiratory limb of a Siemens Ser vo 900C ventilator driven by high pressure oxygen provided a highly va riable concentration (9-53 ppm) of inspired NO.