Wheezing and Airflow Obstruction during Methacholine Challenge in Children with Cystic Fibrosis and in Normal Children

Abstract

To study wheeze as an indicator of bronchial responses during standardized methacholine challenge (MCH), we used computerized analysis of respiratory sounds in children with cystic fibrosis (CF) and in healthy control subjects. We recorded tracheal and lung sounds from 10 young CF = yCF patients, mean age 5.7 yr (range 4 to 7 yr), 13 older CF = oCF, age 10.5 yr (8 to 18 yr), 7 young normal subjects = yNO, age 5.3 yr (4 to 7 yr), and 11 older normal subjects = oNO, age 11 yr (8 to 16 yr). Spirometry was obtained after each doubling concentration of methacholine until the concentration provoking a > or = 20% fall in FEV1 (PC20) or the end point (8 mg/ml) was reached. Sound and calibrated flow signals were recorded on tape and later analyzed by respirosonography. The concentration of methacholine associated with wheeze (PCw) was noted. Wheezing was quantified by its duration during inspiration (Tw/TI) and expiration (TW/TE). We found a positive response to MCH in 11 of 13 oCF (PC20 0.75 mg/ml, range 0.08 to 3.0) and in 3 of 11 oNO (PC20 4.2 mg/ml, range 2.5 to 6.5). Wheezing occurred in 6 oCF (PC20 < 8 mg/ml). In 7 yCF PC20 or PCW developed (1.51 mg/ml, range 0.125 to 4.0) versus 4 yNO (4.0 mg/ml, range 2.0 to 8.0). In 10 oCF subjects who performed MCH on three occasions within a 2-wk period, both positive and negative wheeze responses were reproducible. Patients who wheezed had a lower FRC compared with patients who did not (109 versus 147% of predicted, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Cystic fibrosis, atopy, asthma and ABPA

“…35 Once other causes of serum total IgE elevation are excluded, particularly allergic bronchopulmonary aspergillosis (ABPA), it can also constitute a guide to atopic status, strengthening the diagnosis of CF asthma in opposition to ''CF wheezers'' without asthma. 36 Atopy can also be confirmed through positive skin prick testing or serum specific IgE tests when common aeroallergens such as house dust mite, cat, dog, grass and tree pollens, are involved. On the other hand, as stated by Balfour-Lynn, a reaction to Aspergillus does not necessarily denote atopy, but this will be discussed later.…”

Computerized Adventitious Respiratory Sounds as Outcome Measures for Respiratory Therapy: A Systematic Review

“…The majority of the included studies were quasi-experimental, 5,[20][21][22][23][24][25] 3 studies were observational, [26][27][28] and 2 studies were randomized controlled trials (Table 2). 29,30 Ten studies recruited patients receiving specialized care, and 2 studies recruited patients during hospital admission.…”

“…Eight studies were conducted with adults (n ϭ 167; 60.7%; age range 21-73 years) 5,21,24-29 and 4 with children (n ϭ 108 [39.3%]; age range 4 months-18 y). 20,22,23,30 The interventions in most studies consisted of pharmacotherapy [20][21][22][23][24][25][26][27][28][29][30] ; only 2 studies combined pharmacotherapy with respiratory physical therapy. 5,29 The respiratory physical therapy consisted mainly of an active cycle of breathing techniques, 5,29 but also breathing retraining techniques (incentive spirometry, thoracic mobility, expansion and flexibility exercises, and aerobic training).…”

“…The recording devices used varied among studies, as follows: microphones 21,24,25,27,29 ; piezoelectric sensors 20,22,23,26,30 ; and electronic stethoscopes. 5,28 Algorithms based on fast Fourier transformation were the most used to automatically detect ARSs.…”

“…The presence of WHs was used to identify a bronchial response during bronchial provocation tests in 2 studies conducted with children. 20,22 Sanchez et al 20 used concentrations of methacholine, and found that WHs had 50% sensitivity and 100% specificity to detect bronchial hyper-reactivity. Bentur et al 22 observed that WHs were detected at a mean adenosine concentration of 15.6 mg/ mL.…”