It is often difficult to listen to air movement and breath sounds in an infant between birth and 1 year of age because his (or her) fast, shallow breathing can make adventitious sounds such as rhonchi, rales, and wheezes hard to detect. I solve the problem by putting the baby on his belly. The infant stops squirming or moving around in this position because it minimizes body flexion and lower extremity extension. The child usually raises his head and extends his neck, which opens the upper airway. Also, the prone position increases intra-abdominal pressure. To counter the increased pressure, the baby reflexively takes slower, deeper, more prolonged breaths than if he were lying on his back.
C. D. Nguyen, MDOkemos, Mich.