All of the following are early signs of respiratory distress in pediatric patients EXCEPT:

Cyanosis is a late sign of respiratory distress in pediatric patients rather than an early sign. Early signs typically include restlessness, increased heart rate, and the use of accessory muscles, which indicate that the body is starting to struggle for adequate oxygenation and ventilation.

Restlessness reflects the child’s discomfort or anxiety due to inadequate oxygen levels, which stimulates the autonomic nervous system. An increased heart rate is a compensatory mechanism as the body attempts to deliver more oxygen to tissues in response to respiratory distress. The use of accessory muscles indicates that the child's normal breathing efforts are insufficient; they are engaging additional muscles to aid in respiration, which is a clear sign of mounting distress.

Cyanosis, on the other hand, represents a significant decrease in oxygen saturation in the blood and typically appears later when the child is experiencing significant hypoxia. By this point, interventions may need to be urgently implemented to prevent serious complications.