Which of the following is a sign of respiratory distress?

The use of accessory muscles for breathing is indeed a significant sign of respiratory distress. When the body is struggling to obtain sufficient oxygen or expel carbon dioxide, it often recruits additional muscles beyond the primary diaphragm and intercostal muscles to aid the respiratory process. These accessory muscles include those in the neck, shoulders, and abdomen. Their use indicates that the respiratory system is under strain, suggesting that normal breathing mechanics may not be adequate to meet the body’s demands.

In contrast, normal lung auscultation would imply that the airflow through the lungs is unobstructed and sounds are as expected, which does not suggest any distress. Bradycardia, or a slow heart rate, can be associated with various conditions but is not a direct indicator of respiratory distress. Lastly, stable oxygen saturation levels would suggest that the oxygenation of the blood is adequate, contradicting the presence of respiratory distress. Thus, the indication of accessory muscle use is a clear and visible sign that the patient may be experiencing respiratory difficulties.