Methacholine responsiveness in infants assessed with low frequency forced oscillation and forced expiration techniques

Hall, G. L.; Hantos, Z.; Wildhaber, J. H.; Peták, F.; Sly, P. D.
January 2001
Thorax;Jan2001, Vol. 56 Issue 1, p42
Academic Journal
Background-The contribution of the pulmonary tissues to the mechanical behavior of the respiratory system is well recognized. This study was undertaken to detect airway and lung tissue responses to inhaled methacholifle (Mch) using the low frequency forced oscillation technique (LEOT). Methods-The respiratory system impedance (Zrs, 0.5-20 Hz) was determined in 17 asymptomatic infants. A model containing airway resistance (Raw) and inertance (law) and a constant phase tissue damping (G) and elastance (H) was fitted to Zrs data. Tissue hysteresivity (η) was calculated as η=G/H. The raised volume rapid thoracic compression technique (RVRTC) was used to generate forced expiration volume in 0.5 seconds (FEV0.5. Lung function was determined at baseline and following inhaled Mch in doubling doses (0.25-16 mg/ml) until the maximal dose was reached or a fall of 15% in FEV0.5 was achieved (PC15FEV0.5). The response to Mch was defined in terms of the concentration of Mch provoking a change in lung function parameters of more than two standard deviation units (threshold concentration) Results-At PC15FEV0.5 a response in Raw, law, G, and η, but not H, was detected (mean (SE) 61.28 (12.22)%, 95.43 (34.31)%, 46.28 (22.36)%, 44.26 (25.83)%, and -6.48 (4.94)%, respectively). No significant differences were found between threshold concentrations of LFOT parameters and FEV05. Conclusions-Inhaled Mch alters both airway and respiratory tissue mechanics in infants.


Related Articles

  • Diaphragm plication following phrenic nerve injury: a comparison of paediatric and adult patients. Simonsky, D. A.; Paley, M.; Refaely, Y.; Yellin, A. // Thorax;Jul2002, Vol. 57 Issue 7, p613 

    Background: A study was undertaken to evaluate whether adults differ from children in the indications and outcome of diaphragmatic plication following phrenic nerve injury. Methods: A retrospective study was performed of 21 patients, 10 below the age of 5 and 11 older than 37 years. The...

  • Reference values of interrupter respiratory resistance in healthy preschool white children. Lombardi, E.; Sly, P. D.; Concutelli, G.; Novembre, E.; Veneruso, G.; Frongia, G.; Bernardini, R.; Vierucci, A. // Thorax;Sep2001, Vol. 56 Issue 9, p691 

    Background--Interrupter respiratory resistance (Rim) is reported to be useful in evaluating lung function in poorly collaborating patients. However, no reference values are available from large samples of preschool children using the standard interrupter method. The aim of this study was to...

  • Neonatal lung function and later asthma.  // Archives of Disease in Childhood -- Education & Practice Edition;Feb2007, Vol. 92 Issue 1, p28 

    The article presents the results of a Norwegian study on the link between reduced early neonatal lung function and asthma at the age of 10 years. Measures of early neonatal lung function used were the ratio, expiratory time to peak tidal expiratory flow:total expiratory time (tPTEF/tE) and...

  • Feasibility, tolerability and safety of pediatric hyperpolarized Xe magnetic resonance imaging in healthy volunteers and children with cystic fibrosis. Walkup, Laura; Thomen, Robert; Akinyi, Teckla; Watters, Erin; Ruppert, Kai; Clancy, John; Woods, Jason; Cleveland, Zackary // Pediatric Radiology;Nov2016, Vol. 46 Issue 12, p1651 

    Background: Hyperpolarized Xe is a promising contrast agent for MRI of pediatric lung function, but its safety and tolerability in children have not been rigorously assessed. Objective: To assess the feasibility, safety and tolerability of hyperpolarized Xe gas as an inhaled contrast agent for...

  • Carbon in Airway Macrophages and Lung Function in Children. Kulkarni, Neeta; Pierse, Nevil; Rushton, Lesley; Grigg, Jonathan // New England Journal of Medicine;7/6/2006, Vol. 355 Issue 1, p21 

    Background: Epidemiologic studies indirectly suggest that the inhalation of carbonaceous particulate matter impairs lung function in children. Using the carbon content of airway macrophages as a marker of individual exposure to particulate matter derived from fossil fuel, we sought direct...

  • Asthma in Childhood -- Making the Diagnosis. Paton, James Y. // Current Pediatric Reviews;2010, Vol. 6 Issue 2, p112 

    Asthma is amongst the commonest chronic illnesses of childhood yet there is no single objective test that results in a definitive diagnosis. Diagnosis remains clinical, especially in young children. At present, asthma diagnosis in children is best viewed as a process. The initial steps include a...

  • Pulmonary Function of Children With Asthma in Selected Indoor Sport Environments. Pelham, Thomas W.; Holt, Laurence E.; Moss, Michael A. // Pediatric Exercise Science;Nov1999, Vol. 11 Issue 4, p406 

    Examines the pulmonary function of children with asthma in indoor sport environments in Halifax, Nova Scotia. Decrease on the forced expiratory volume (FEV) and FEVT of the children after exercise in the ice rink; Assessment on the decrease of FEV and FEVT after gymnasium and pool activity;...

  • Pulmonary Function and Health Status of Children in Two Cities of Different Air Quality: A Pilot Study. Sharratt, Michael T.; Cerny, Frank J. // Archives of Environmental Health;Mar/Apr79, Vol. 34 Issue 2 

    Examines the pulmonary function and health status of children with different air qualities in England. Identification of differences and trends in pulmonary function; Influence of respiratory infection on the development of chronic respiratory disease; Determination of the physical...

  • Respiratory Symptoms and Lung Function in Jute Processing Workers: A Primary Investigation. Chen Zhou; Zenlin Liu; Chinshan Ho; Jiezhi Lou // Archives of Environmental Health;Nov/Dec89, Vol. 44 Issue 6 

    Investigates the respiratory symptoms and lung function of jute mill workers exposed to jute dust. Measurement of dust concentration; Prevalence of cough and chest tightness following exposure; Incidence of abnormal lung functions among dust-exposed workers.


Read the Article


Sign out of this library

Other Topics