Which of the following indicates respiratory distress in infants?

Grunting at the end of each breath is a physiological response that indicates respiratory distress in infants. This sound occurs when an infant is trying to increase end-expiratory lung volume and enhance oxygenation. It typically indicates that the infant is struggling to breathe effectively, which can result from various underlying respiratory issues such as pneumonia, asthma, or congenital heart defects.

In contrast, calm breathing, consistent crying, and normal feeding patterns do not signify respiratory distress. Calm breathing indicates that the infant is managing their respiratory function adequately. Consistent crying can occur for various reasons, including hunger or discomfort, without specifically indicating issues with breathing. Similarly, normal feeding patterns suggest stability and well-being rather than distress. Thus, the presence of grunting serves as a key sign for healthcare providers to recognize potential respiratory issues requiring further assessment and intervention.