What is a notable clinical sign in a newborn particularly concerned for respiratory distress syndrome?

In a newborn suspected of having respiratory distress syndrome, expiratory grunting is a notable clinical sign. This sound occurs when an infant attempts to improve their oxygenation by increasing end-expiratory lung volume. When a newborn is in respiratory distress, the body employs various mechanisms to compensate for impaired gas exchange, and grunting is one of these mechanisms, often indicating that the infant is struggling to breathe effectively. The presence of grunting is a clear signal of respiratory compromise and requires immediate attention.

Cold extremities could suggest poor perfusion or hypothermia, while decreased urination typically points to dehydration or decreased renal perfusion, neither of which are specific indicators of respiratory distress syndrome. Excessive crying might indicate distress or discomfort in general but does not specifically indicate a respiratory issue. Thus, expiratory grunting distinctly highlights a critical respiratory challenge in the newborn, making it the most relevant sign associated with respiratory distress syndrome.