What is a common late sign that may suggest impending respiratory failure?

Bradycardia is a common late sign that may indicate impending respiratory failure, particularly in pediatric patients. As respiratory distress progresses, the body's demand for oxygen increases, and if the situation worsens to the point of significant hypoxia, the heart rate can decrease, resulting in bradycardia. This is often a physiological response to inadequate oxygenation and an indicator that the child may be moving towards respiratory failure.

In contrast, increased urinary output is typically not associated with respiratory failure; in fact, during significant respiratory distress, systemic blood flow and renal perfusion can be compromised, often leading to decreased urine output. Swelling of limbs does not correlate with respiratory function but may indicate other issues like fluid overload or heart failure. An elevated temperature may suggest infection or inflammation but does not specifically indicate respiratory failure. Thus, the presence of bradycardia is a critical sign that alerts healthcare providers to the need for immediate intervention in the context of potential respiratory compromise.