nitrogen-dioxide and Cystic-Fibrosis

Nitrogen multiple-breath washout (N2 MBW) is a promising tool for assessing early lung damage in children with chronic obstructive pulmonary disease, but it can be a time-consuming procedure. We compared alternative test-shortening endpoints with the most commonly reported N2 MBW outcome, the lung clearance index, calculated as lung volume turnovers required to reach 2.5% of the starting N2 concentration (LCI2.5 ).. Cross-sectional study of triplicate N2 MBW measurements obtained in cystic fibrosis (CF) patients (N = 60), primary ciliary dyskinesia (PCD) patients (N = 28), and matched healthy controls (N = 48) aged 5-18 years. Bland-Altman analysis was used to compare LCI2.5 with earlier LCI endpoints (3%, 4%, 5%, 7%, and 9% of starting N2 concentration), Cn@TO6 (defined as % of N2 starting concentration when reaching six lung volume turnovers), and LCI derived from only two N2 MBW runs in each session. N2 MBW endpoints were analyzed as z-scores calculated from healthy controls.. In PCD, Cn@TO6 and LCI2.5 exhibited similar values (mean [95%CI] difference: 0.33 [-0.24; 0.90] z-scores), reducing the test duration by one-third (5.4 min; 95%CI: 4.0; 6.8). All other tested alternative endpoints exhibited increasing disagreement with increasing LCI2.5 . With an average reduction in test duration of 40%, LCI2.5 derived from two runs exhibited good agreement in all children.. Cn@TO6 may be suggested as a potential test-shortening endpoint in school children with PCD. In CF, early test termination may reduce measurement power with advancing pulmonary disease, suggesting differences in underlying pathophysiology. Two technically acceptable N2 MBW runs may be sufficient in school children irrespective of diagnosis with CF or PCD. Pediatr Pulmonol. 2016;51:624-632. © 2015 Wiley Periodicals, Inc.

Topics: Adolescent; Breath Tests; Child; Child, Preschool; Cross-Sectional Studies; Cystic Fibrosis; Female; Functional Residual Capacity; Humans; Lung; Lung Diseases, Obstructive; Male; Nitrogen Dioxide; Prospective Studies; Respiratory Function Tests; Tidal Volume; Total Lung Capacity

Pulmonary exacerbations in cystic fibrosis (CF) contribute to the burden of disease, with a negative impact on quality of life, costs, and lung function. Our aim was to evaluate whether exacerbations, defi ned by antibiotic use, were triggered by daily fl uctuations in air pollution.. In a case-crossover analysis, we evaluated 215 patients with CF and pollution data from January 1, 1998, to December 31, 2010. Exacerbation was defi ned as the start of IV or oral antibiotic use in a home or hospital setting. We calculated regional background levels of particulate matter with a diameter , 10 m m (PM 10 ), ozone, and nitrogen dioxide (NO 2 ) on the day of the event and on the 2 days prior to the event at each patient’s home address. We matched for day of the week and controlled for temperature on the day of the event and the 2 preceding days. In the month where antibiotic treatment was started, all days with the same temperature ( 2°C) as the event day served as control days, excluding 3 days before and after the start of treatment.. A total of 215 patients (male sex, 49%, mean age, 21 13 years) had 2,204 antibiotic treatments (1,107 IV and 1,097 oral). Over a period of 12 years, an increase in risk of antibiotic use was associated with increasing concentrations of PM 10 , NO 2 , and ozone on the event day and for NO 2 on the day before. A tendency toward signifi cance was seen the day before antibiotic use for PM 10 and ozone. Overall, a rise in OR was seen from 2 days before until the day of the start of antibiotics.. In patients with CF and exacerbations, ambient concentrations of ozone, PM 10 , and NO 2 play a role in triggering an exacerbation.

Topics: Administration, Intravenous; Administration, Oral; Adolescent; Adult; Air Pollution; Anti-Bacterial Agents; Child; Cross-Over Studies; Cystic Fibrosis; Disease Progression; Female; Humans; Male; Nitrogen Dioxide; Ozone; Particulate Matter; Retrospective Studies; Temperature; Young Adult

Multiple-breath washout (MBW)-derived lung clearance index (LCI) is a sensitive measure of ventilation inhomogeneity in patients with cystic fibrosis (CF), but LCI measurement is time consuming. We systematically assessed ways to shorten LCI measurements. In 68 school-aged children (44 with mild CF lung disease) three standard nitrogen (N2) MBWs were applied. We assessed repeatability and diagnostic performance of (1) LCI measured earlier from three MBW runs and (2) LCI measured at complete MBW (1/40th of starting N2 concentration) from two runs only. Compared with the standard LCI from three complete MBW runs, the new LCI based on three N2MBW runs until 1/20th, or two complete runs until 1/40th, provided similar or better repeatability as well as sensitivity and specificity for CF lung disease. Alternative ways to measure LCI reduced test duration in children with CF by 30% and 41%, respectively. LCI measurements can be reliably shortened in children. These new MBW protocols may advance the transition of LCI from research into clinical settings.

Topics: Adolescent; Breath Tests; Child; Cystic Fibrosis; Exhalation; Female; Forced Expiratory Volume; Humans; Lung Diseases; Male; Nitrogen Dioxide; ROC Curve