What clinical sign is indicative of respiratory distress in the examined infant?

Intercostal retractions are a significant clinical sign indicative of respiratory distress, especially in infants. This occurs when the muscles between the ribs (intercostal muscles) contract more significantly as the infant struggles to breathe, resulting in a noticeable pulling in of the skin and muscles between the ribs during inhalation. This indicates that the infant is using more effort than normal to breathe, signifying that they may be experiencing difficulty in getting adequate air into their lungs.

Nasal congestion can be a common occurrence in infants and does not necessarily indicate respiratory distress. It can occur due to various benign reasons, such as a cold or allergies, and does not reflect the infant's overall respiratory effort.

Cyanosis of the lips is a concerning sign that can indicate hypoxia (low oxygen levels). While it is serious and warrants immediate attention, it is not as specific as intercostal retractions in showing that an infant is actively struggling to breathe.

Bradycardia, a slowing heart rate, can occur in some respiratory conditions but is not a direct indicator of respiratory distress. Instead, it could be a sign of low oxygenation, but does not necessarily reflect the infant's immediate effort in respiration.

In summary, intercostal retractions are a clear