title: Feasibility of multiple breath washout measurements in infants with bronchiolitis: A pilot study.
abstract: Lung clearance index (LCI) reflects ventilation inhomogeneity and is raised in obstructive airway disease. Feasibility of multiple breath washout (MBW) measurement during acute lung disease in infants is unknown. As a further measure of disease, exhaled nitric oxide (eNO) may paradoxically decrease in acute bronchiolitis. We hypothesized that MBW measurements were attainable in infants with bronchiolitis and that LCI was raised and eNO reduced, compared to normal controls.
  
  
  
  Infants with acute bronchiolitis were tested with sulfur hexafluoride (SF6) MBW during hospitalization and compared to controls. Tidal breathing and eNO parameters were obtained. Measurements were performed during natural sleep.
  
  
  
  Twenty-nine infants with bronchiolitis aged 3.7 ± 2.3 months (mean ± SD) and 23 controls aged 4.2 ± 2.5 months (P = 0.07) were evaluated. Fifteen of 29 (52%) infants with bronchiolitis and 19/23 (83%) controls achieved ≥2 valid MBW measurements. Reasons for test failure included waking up during facemask application and an irregular respiratory pattern. LCI was 8.4 ± 0.8 in the study group and 7.3 ± 0.7 in controls (P < 0.001). ENO was 2.3 ± 2.7 ppb in the study group and 7.9 ± 6.9 ppb in controls (P = 0.004).
  
  
  
  MBW measurements during natural sleep are feasible but technically challenging in infants with acute bronchiolitis. LCI is raised compared to healthy controls. Larger trials, possibly using sedation protocols and shortened washout periods, are required to corroborate these findings. LCI can potentially serve as an objective indicator of severity and could be considered as a biomarker for future interventional trials.
authors.affiliation: Pulmonary Institute, Schneider Children's Medical Center of Israel, Petah Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Patrick
authors.initials: P
authors.lastname: Stafler
authors.affiliation: Pulmonary Institute, Schneider Children's Medical Center of Israel, Petah Tikva, Israel.
authors.forename: Sigal
authors.initials: S
authors.lastname: Weinreb
authors.affiliation: Pulmonary Institute, Schneider Children's Medical Center of Israel, Petah Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Huda
authors.initials: H
authors.lastname: Mussaffi
authors.affiliation: Pulmonary Institute, Schneider Children's Medical Center of Israel, Petah Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Meir
authors.initials: M
authors.lastname: Mei-Zahav
authors.affiliation: Pulmonary Institute, Schneider Children's Medical Center of Israel, Petah Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Dario
authors.initials: D
authors.lastname: Prais
authors.affiliation: Pulmonary Institute, Schneider Children's Medical Center of Israel, Petah Tikva, Israel.
authors.forename: Guy
authors.initials: G
authors.lastname: Steuer
authors.affiliation: Pulmonary Institute, Schneider Children's Medical Center of Israel, Petah Tikva, Israel.
authors.forename: Ophir
authors.initials: O
authors.lastname: Bar-On
authors.affiliation: Clalit Research Institute, Tel Aviv, Israel.
authors.forename: Moshe
authors.initials: M
authors.lastname: Hoshen
authors.affiliation: Pulmonary Institute, Schneider Children's Medical Center of Israel, Petah Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Hannah
authors.initials: H
authors.lastname: Blau
mesh_terms: D001944:Breath Tests / Q000379:methods*; D001988:Bronchiolitis / Q000175:diagnosis* / Q000378:metabolism; D045853:Exhalation; D005260:Female; D006801:Humans; D007223:Infant; D008168:Lung / Q000378:metabolism; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D010865:Pilot Projects; D012720:Severity of Illness Index; D013459:Sulfur Hexafluoride
chemical_list: D009569:Nitric Oxide; D013459:Sulfur Hexafluoride
keywords: bronchiolitis; infant lung function; lung clearance index; multiple breath washout; respiratory syncytial virus