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.


METHODS
In a standard pediatric intensive care room, 800 ppm NO was delivered to a high-frequency oscillator and mixed with 100% O2 to obtain 20 ppm NO in the inspiratory gas flow. NO and NO2 concentrations in room air were measured using a chemiluminescence analyzer. Air samples 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.


METHODS
Pediatric intensive care unit in a university children's hospital.


RESULTS
Maximal concentrations of NO and NO2 were reached after 4 h NO use. Without exhaust, in a nonventilated room, environmental NO and NO2 concentration rose to a maximum of 0.462 and 0.064 ppm, respectively. With the use of an expiratory gas exhaust, NO and NO2 concentrations were 0.176 and 0.042 ppm, respectively. With normal air-conditioning, these values were 0.075 and 0.034 ppm, respectively, without the use of an expiratory gas exhaust. With expiratory gas exhaust added to normal air-conditioning, values for NO and NO2 were 0.035 and 0.030 ppm, respectively.


CONCLUSIONS
The use of 20 ppm NO, even under minimal room ventilation conditions, did not lead to room air levels of NO or NO2 that should be considered toxic to adjacent intensive care patients or staff. Slight increases in NO and NO2 concentrations were measurable but remained within occupational safety limits. The use of an exhaust system and normal room ventilation lowers NO and NO2 concentrations further to almost background levels.
Markhorst
D G
DG
Free University Hospital Amsterdam, Department of Pediatrics, The Netherlands.
Leenhoven
T
T
Uiterwijk
J W
JW
Meulenbelt
J
J
van Vught
A J
AJ
D000280:Administration, Inhalation; D000389:Air Conditioning; D000395:Air Pollutants, Occupational / Q000032:analysis*; D004784:Environmental Monitoring; D006801:Humans; D015278:Intensive Care Units, Pediatric / Q000706:statistics & numerical data*; D008452:Maximum Allowable Concentration; D009426:Netherlands; D009569:Nitric Oxide / Q000032:analysis*; D009585:Nitrogen Dioxide / Q000032:analysis; D016273:Occupational Exposure / Q000706:statistics & numerical data*; D010564:Personnel, Hospital / Q000706:statistics & numerical data*; D013997:Time Factors; D014691:Ventilation
D000395:Air Pollutants, Occupational; D009569:Nitric Oxide; D009585:Nitrogen Dioxide