Generation of nitrogen dioxide during nitric oxide therapy and mechanical ventilation of children with a Servo 900C ventilator

Abstract

The generation of NO2 in the ventilator circuit is directly proportional to concentration of NO and O2 and inversely proportional to the TGF and MV but uninfluenced by the TGF/MV ratio. NO 80 ppm, but neither 20 nor 40 ppm in FIO2 of 0.6, generates toxic NO2 irrespective of TGF, MV or the TGF/MV ratio.

Production of nitrogen dioxide during nitric oxide therapy using the Servo Ventilator 300 during volume‐controlled ventilation

“…However, the measured concentrations of nitrogen dioxide in delivery systems have not always been consistent with theoretical calculations (12,15), and there may be a considerable difference in the generation of nitrogen dioxide depending on the design of the administration system. (10,20,40,60,80, and 100 ppm) and an FIO 2 of 0.9.…”

“…The concentration of nitrogen dioxide is also dependent on the point at which the nitric oxide/nitrogen stock gas solution is mixed into the ventilatory system, since this may affect the residence time of ni-tric oxide with oxygen. Several studies have been performed to evaluate the production of nitrogen dioxide in systems where a constant proportion of oxygen to nitric oxide is mixed before the ventilator and directed into the low or high pressure inlet of the ventilator (18)(19)(20)(21). These systems seem to generate higher concentrations of nitrogen dioxide at comparable settings and this can be due to a longer residence time of nitric oxide with oxygen, although mixing point, tube size, ventilatory gas flow and concentration of nitric oxide are not always specified in these articles.…”

An Evaluation of Nitric Oxide and Nitrogen Dioxide Absorbers and Filters

“…The best performing absorbers from the bench tests and all filters were tested once each in conjunction with the use of a ventilator. A Servo 900C ventilator (Siemens-Elema AB, Solna, Sweden) was set up as previously described 2 . Tests were conducted at NO and NO 2 levels of 80 and 4 ppm and 20 and 0.5 ppm respectively.…”