This short communication describes a simple technique that can be used during auscultation of the lungs. The use of this technique may provide valuable information that might not otherwise be obtained during the physical examination.
A large volume of gas may be moved through a narrow passage with minimal or no turbulence, if the gas is under low pressure and is moved slowly. However, even a small amount of gas will produce a great deal of turbulence, and even noise, if it is moved rapidly at high pressure through the same opening. This principle can be applied to auscultation of the lungs of an asthmatic child.
The detection of rhonchi and wheezing in asthmatic children is indicative of narrowing of the air passage due to inspissated mucus, edema of the bronchial mucosa, or spasm of the bronchial musculature. This may occur to a variable degree. We are all familiar with
HOROWITZ L. Expiratory Thrust, an Aid in Physical Diagnosis. Am J Dis Child. 1963;105(3):300. doi:10.1001/archpedi.1963.02080040302015