OCCUPATIONAL EXPOSURE DURING NITRIC-OXIDE INHALATIONAL THERAPY IN A PEDIATRIC INTENSIVE-CARE SETTING

Objective: To determine the amount of occupational exposure to nitric oxide (NO) and nitrogen dioxide (NO2) during NO inhalational therapy. Design: In a standard pediatric intensive care room, 800 ppm NO was de livered to a high-Frequency oscillator and mixed with 100% O-2 to obta in 20 ppm NO in the inspiratory gas flow. NO and NO2 concentrations in room air were measured using a chemiluminescence analyzer. Air sample s were taken from a height of 150 cm at a horizontal distance of 65 cm from the ventilator in a nonventilated and in a well-ventilated room with and without an expiratory gas exhaust under normal intensive care environmental conditions. Setting: Pediatric intensive care unit in a university children's hospital. Mesaurement and results: Maximal conc entrations of NO and NO2 were reached after 4 h NO use. Without exhaus t, in a nonventilated room, environmental NO and NO2 concentration ros e to a maximum of 0.462 and 0.064 ppm, respectively. With the use of a n expiratory gas exhaust, NO and NO2 concentrations were 0.176 and 0.0 42 ppm, respectively. With normal air-conditioning, these values were 0.075 and 0.034 ppm, respectively, without the use of an expiratory ga s exhaust. With expiratory gas exhaust added to normal air-conditionin g, values for NO and NO2 were 0.035 and 0.030 ppm, respectively. Concl usions: The use of 20 ppm NO, even under minimal room ventilation cond itions, did not lead to room air levels of NO or NO2 that should be co nsidered toxic to adjacent intensive care patients or staff, Slight in creases in NO and NO2 concentrations were measurable but remained with in occupational safety limits, The use of an exhaust system and normal room ventilation lowers NO and NO2 concentrations Further to almost b ackground levels.