Which of the following is a common sign of shock?

Increased heart rate is a common sign of shock because it is a physiological response to maintain adequate blood flow to vital organs when the body's perfusion is compromised. When shock occurs, the body experiences a decrease in blood volume, blood pressure, or effective circulation, prompting the heart to pump faster in an attempt to compensate for the decreased perfusion. This tachycardic response is primarily driven by the autonomic nervous system as it strives to maintain oxygen delivery to tissues.

In contrast, elevated blood pressure is generally not indicative of shock; instead, it may suggest a different condition. Fever is also not a typical sign of shock, as it often indicates infection or another systemic process rather than shock itself. Bradycardia, a slower than normal heart rate, would generally not be expected in a shock state, as it contrasts with the body's compensatory mechanisms seeking to rectify low blood flow or blood pressure situations. Therefore, recognizing an increased heart rate as a sign of shock is crucial for timely identification and intervention in a clinical setting.