Respiratory muscle activity in the assessment of bronchial responsiveness in asthmatic children

• Published in: Journal of applied physiology (1985) 1998-03, Vol.84 (3), p.897-901
• Main Authors: Sprikkelman, Aline B, Van Eykern, Leo A, Lourens, Marlies S, Heymans, Hugo S. A, Van Aalderen, Wim M. C
• Format: Article
• Language: English
• Subjects: Administration, Inhalation; Adolescent; Asthma - physiopathology; Biological and medical sciences; Bronchi - physiopathology; Child; Chronic obstructive pulmonary disease, asthma; Diaphragm - physiopathology; Electromyography; Female; Forced Expiratory Volume; Histamine - administration & dosage; Humans; Intercostal Muscles - physiopathology; Male; Medical sciences; Pneumology; Respiratory Function Tests; Respiratory Muscles - physiopathology
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.1998.84.3.897

1  Beatrix Children's Hospital, University Hospital Groningen, 9700 RB Groningen; 2  Department of Medical Physiology, University of Groningen, 9700 RB Groningen; and 3  Emma Children's Hospital, Academic Medical Center/University of Amsterdam, 1105 AZ Amsterdam, The Netherlands We investigated whether an increase in transcutaneous electromyographic (EMG) activity of the diaphragm and intercostal muscles corresponds with the concentration of histamine that induces a 20% fall in the forced expiratory volume in one second (FEV 1 ; PC 20 ). Eleven asthmatic children (mean age 11.9 yr) were studied after they were given histamine challenge. EMG activity at PC 20 or at the highest histamine concentration was compared with activity at baseline by calculating the ratio of the mean peak-to-peak excursion at the highest histamine dose to that at baseline [EMG activity ratio (EMGAR)]. In all children reaching PC 20 , an increase in diaphragmatic and intercostal EMGAR was observed. No increase was found at the dose step before PC 20 was reached. In six challenges, no fall in FEV 1 was induced, and no increase in EMGAR was seen. In two challenges, no fall in FEV 1 was induced, but increase in diaphragmatic or intercostal EMGAR was observed. Increase in the electrical activity of the diaphragm and intercostal muscles in asthmatic children corresponds closely to a 20% fall in FEV 1 induced by histamine challenge. electromyography; respiratory muscles JAP 84(3):897-901 0161-7567/98 $5.00 Copyright © 1998 the American Physiological Society