VALIDATION OF A SIMPLE METHOD ASSESSING NITRIC-OXIDE AND NITROGEN-DIOXIDE CONCENTRATIONS

Monitoring of nitric oxide (NO) and nitrogen dioxide (NO2) is a prereq uisite for the clinical use of NO. Chemiluminescence, the reference me thod, cannot be used as a routine in clinical practice in view of its cost and other restraints. This study was performed to evaluate a devi ce using an electrochemical method (Polytrons NO and NO2, Drager(R)). Forty-nine simultaneous measurements of NO and various oxides of nitro gen (NOx) concentrations by the two apparatus were performed. NO measu rements by means of these two methods are very well correlated (r = 0. 96; p < 10(-5)). The mean difference according to the method of Bland and Altman was 2.8 +/- 1.7 ppm, with the limits of agreement at -0.6 a nd +6.2 ppm (confidence interval of 95%). There was also a good correl ation between measurements of NO2 obtained via Polytrons and NOx via c hemiluminescence (r = 0.84; p < 10(-5)). However, NO2 measurements obt ained via Polytron may be insufficient to exclude potential toxicity o f NO2 due to the inability to detect measurements in the ppb-range. Th is study demonstrates that devices designed for industrial purposes (P olytrons NO and NO2, Drager(R)) can be used for clinical purposes.