@article {Murthyrespcare.04858, author = {Vydehi R Murthy and Hugo Escobar and Mike Norberg and Charisse I Lachica and Linda L Gratny and Ashley K Sherman and William E Truog and Winston M Manimtim}, title = {A Novel Method of Measuring Fractional Exhaled Nitric Oxide in Tracheostomized Ventilator-Dependent Children}, elocation-id = {respcare.04858}, year = {2017}, doi = {10.4187/respcare.04858}, publisher = {Respiratory Care}, abstract = {BACKGROUND: The lower airway concentration of fractional exhaled nitric oxide (FENO) is unknown in children with chronic lung disease of infancy who have tracheostomy for long-term mechanical ventilation. We aimed to evaluate an online method of measuring FENO in a cohort of ventilator-dependent children with a tracheostomy and to explore the relationship between the peak FENO concentration (FENO peak) and the degree of respiratory support using the respiratory severity score.METHODS: We conducted a prospective cross-sectional study in 31 subjects who were receiving long-term respiratory support through a tracheostomy. We measured the FENO peak and FENO plateau concentration from the tip of the tracheostomy tube using a nitric oxide analyzer in subjects during a quiet state while being mechanically ventilated. We obtained 2 consecutive 2-min duration measurements from each subject. The FENO peak, exhaled NO output (equal to the FENO peak {\texttimes} minute ventilation), and pulmonary NO excretion (exhaled NO output/weight) were calculated and correlated with the respiratory severity score.RESULTS: The median FENO peak was 2.69 ppb, and the median FENO plateau was 1.57 ppb. The coefficients of repeatability between the 2 consecutive measurements for FENO peak and FENO plateau were 0.74 and 0.59, respectively. The intraclass coefficient between subjects within the cohort was 0.988 (95\% CI 0.975{\textendash}0.994, P \< .001) for FENO peak and 0.991 (95\% CI 0.982{\textendash}0.996, P \< .001) for FENO plateau. We found that the FENO peak was directly correlated with minute ventilation, but we did not find a direct relationship between the FENO peak concentration, exhaled NO output, or pulmonary NO excretion and respiratory severity score.CONCLUSIONS: FENO peak and plateau concentration can be measured online easily with a high degree of reliability and repeatability in infants and young children with a tracheostomy. FENO peak concentration from the lower airway is low and influenced by minute ventilation in children receiving mechanical ventilation.}, issn = {0020-1324}, URL = {https://rc.rcjournal.com/content/early/2017/02/28/respcare.04858}, eprint = {https://rc.rcjournal.com/content/early/2017/02/28/respcare.04858.full.pdf}, journal = {Respiratory Care} }