Which of the following is NOT a sign of respiratory distress?

The presence of calm and relaxed posture indicates that the individual is not experiencing respiratory distress. In situations of respiratory distress, patients typically show signs of anxiety or discomfort, which can manifest in their posture. They may lean forward, appear agitated, or keep their body tense as they struggle to breathe.

In contrast, the use of accessory muscles, inability to speak in full sentences, and increased respiratory rate are all signs indicative of respiratory distress. Accessory muscle use indicates extra effort is needed for breathing, while difficulty speaking in full sentences points to compromised breathing capacity. An increased respiratory rate can signal that the body is trying to compensate for insufficient oxygen or an inability to eliminate carbon dioxide effectively. Therefore, the calm and relaxed posture distinctly stands out as not being a sign of respiratory distress.