title: Cough characteristics and FVC maneuver in cystic fibrosis.
abstract: BACKGROUND
  Cough is part of life in patients with cystic fibrosis (CF). Weak coughing may add to increased respiratory disease that affects the mechanical properties of cough in these patients. In this study, we investigated cough characteristics in relation to forced expiratory flow/volume indices in CF.
  
  
  METHODS
  This prospective study included 54 subjects (26 ± 10 y old) with CF. Similar indices of the maneuvers were compared. Additionally, other cough characteristics revealed by the maneuvers were investigated. Cough was considered efficient with 6 or more secondary spikes at a flow of > 2.67 L/s.
  
  
  RESULTS
  Cough peak flows similar to peak expiratory flows (regardless of FEV1 severity level) were found in 98% of subjects. The secondary spike flows deteriorated alongside the percent-of-predicted FEV1 (r(2) = 0.17, P = .002), yet inefficient secondary spike flows could also be found when FEV1 was within normal range. Mean efficient spike number was low (2.5 ± 1.2 spikes/maneuver). Most cough spike flows were very small (< 0.9 L/s), resembling vibration that may contribute to the propulsion of mucus toward the central airways. Cough maneuver duration ended faster than forced expiration duration (3.7 ± 1.7 s vs 6.8 ± 2.5 s, P < .001), resulting in a smaller cough vital capacity compared with expiratory vital capacity (2.1 ± 0.9 l vs 3.1 ± 0.7 l, P < .001). Inspiratory volume below 2.23 ± 0.07 L reduced efficient secondary spike number.
  
  
  CONCLUSIONS
  The cough flow/volume maneuver reveals abnormalities in cough velocities and volume. A low secondary spike correlates with FEV1 severity level. The method may lead to earlier intervention to assist cough in CF.
authors.affiliation: Pediatric Pulmonary Unit and The National Center for Cystic Fibrosis, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. daphna.vilozni@sheba.health.gov.il avi_vil@bezeqint.net.
authors.forename: Daphna
authors.initials: D
authors.lastname: Vilozni
authors.affiliation: Pediatric Pulmonary Unit and The National Center for Cystic Fibrosis, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Moran
authors.initials: M
authors.lastname: Lavie
authors.affiliation: Pediatric Pulmonary Unit and The National Center for Cystic Fibrosis, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Miryam
authors.initials: M
authors.lastname: Ofek
authors.affiliation: Pediatric Pulmonary Unit and The National Center for Cystic Fibrosis, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Ifat
authors.initials: I
authors.lastname: Sarouk
authors.affiliation: Pediatric Pulmonary Unit and The National Center for Cystic Fibrosis, The Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Ramat Gan, Israel Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Ori
authors.initials: O
authors.lastname: Efrati
mesh_terms: D000328:Adult; D015992:Body Mass Index; D003371:Cough / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000235:genetics / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000503:physiopathology; D013147:Spirometry; D014797:Vital Capacity; D055815:Young Adult
keywords: cough; cystic fibrosis; lung mechanics; spirometry