Which finding is NOT a common early sign of respiratory distress?

The identification of a normal heart rate as not being a common early sign of respiratory distress is rooted in the physiological responses of the body to oxygen deprivation and increased effort in breathing. In situations of respiratory distress, the body's demand for oxygen typically escalates, leading to an increase in heart rate as the cardiovascular system attempts to meet the oxygen needs of the tissues.

Restlessness, coughing, and diaphoresis are indeed common early signs of respiratory distress. Restlessness may occur as a result of hypoxia or anxiety related to the difficulty in breathing. Coughing can be a reflexive action aimed at clearing the airways or responding to irritants in the respiratory tract. Diaphoresis often arises due to the stress of struggling to breathe, as the body activates its fight-or-flight response.

In contrast, maintaining a normal heart rate in the context of respiratory distress may indicate that the distress is either mild or not yet severe enough to provoke a compensatory tachycardic response. Therefore, recognizing a normal heart rate in this scenario underscores a deviation from the expected physiological response, marking it as the correct choice for this question.