Efficacy and safety of methacholine bronchial challenge performed by auscultation in young asthmatic children

The measurement of bronchial reactivity is an important aid in the diagnosi s of asthma, but the technique using spirometry is not feasible in young ch ildren. The aim of the present study was to determine the efficacy and safe ty of a modification of the chest auscultation method in the assessment of bronchial reactivity to inhaled methacholine in young asthmatic children. O ne hundred forty-six young children with asthma (mean age, 4.3 yr) underwen t bronchial challenges with nebulized methacholine using the auscultation m ethod (PCW). The end point was defined as the appearance of wheezing, oxyge n desaturation, or tachypnea. For comparison, 30 children and young adults with asthma underwent bronchial provocation with methacholine using spirome try (PC20). A positive response using the auscultation method was observed in 95.9% of the younger children, and wheezes alone or in combination with other signs appeared in 80.8% of them. The mean desaturation at the end poi nt was 4.6% (PCW) and 5.0% (PC20), with a similar pattern in the two groups . Cough was not helpful in determining the end point. We conclude that the modified auscultation method is effective and safe, with wheeze appearing a t the end point in the large majority of the children.