RESUMO
To evaluate the feasibility of delivering NO through N_2O path in anesthesia machine,NO at 800 ppm was delivered through nitrous oxide path in anesthesia machine SIEMENS Ventilator 710 or NARKOMED 2B,to ventilate a test lung. The minute volume of ventilation (MV) was set from 2 to 6L/min, and NO concentration from 10 to 80 ppm. NO and NO_2 concentrations were measured by hemiluminescence and electro-chemical fuel cell technique. SIEMENS Ventilator 710:Non-rebreathing model,its inspiratory limb was prolonged to 7 meters,the NO level was adjusted at 80ppm before passing through soda lime, NO and NO_2 samples were taken before absorber,after absorber, 1, 2,4 and 6 meter site in inspiratory limb. NARKOMED 2B:Oxygen flows were at the rates epual to the MV mentioned above, NO concentration was at 10,20,40,60 and 80 ppm,the inspiratory gas mixture was sampled immediately passing through absorber, NO_2 levels were less than 5.0ppm in all conditions listed above. With SIEMENS Ventilator 710, the highest level of NO_2 was 3.45 ppm before absorber and 2.43 ppm after absorber,with NARKOMED 2B,that was 3.6 ppm. As MV increased,NO_2 level before absorber decreased (P