PT - JOURNAL ARTICLE AU - Vydehi R Murthy AU - Hugo Escobar AU - Mike Norberg AU - Charisse I Lachica AU - Linda L Gratny AU - Ashley K Sherman AU - William E Truog AU - Winston M Manimtim TI - A Novel Method of Measuring Fractional Exhaled Nitric Oxide in Tracheostomized Ventilator-Dependent Children AID - 10.4187/respcare.04858 DP - 2017 May 01 TA - Respiratory Care PG - 595--601 VI - 62 IP - 5 4099 - http://rc.rcjournal.com/content/62/5/595.short 4100 - http://rc.rcjournal.com/content/62/5/595.full AB - 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 × 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 0.975–0.994, P < .001) for FENO peak and 0.991 (95% CI 0.982–0.996, 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.