Introduction: Accurate monitoring of nitric oxide (NO) and nitrogen dioxide (NO2) during NO therapy is critical to avoiding potential toxicities. The purpose of this experiment was to determine the performance of 4 commercially available analyzers when used in a variety of different environments when compared to highly accurate methods of analysis using standard reference materials (SRMs).

Methods: Using NIST certified SRMs and permeation devices 2 electrochemical (EC) (Pulmonox, Drager) and 2 chemiluminescence (CL)(EcoPhysics, Sievers) analyzers were tested in 100% nitrogen (N2), 21% oxygen(RA) and 100% oxygen (O2) in presence NO2 alone and NO/NO2 combination. This testing was performed in the Gas Metrology Lab at NIST in accordance with NIST protocols.

Results: The following NO and NO2 readings were obtained (see below):

Conclusions: Both EC and CL analyzers function most accurately in N2 and least accurately in O2. EC tends to overestimate NO2 in the presence of high NO and O2. One CL underestimated NO2. NO readings were reasonably accurate. Both EC and CL analyzers are sufficiently accurate for clinical use.Table

Table 1
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