Which of the following is a sign of hypovolemic shock that a nurse should monitor for?

Monitoring for a rapid heart rate is crucial in the context of hypovolemic shock because it reflects the body’s compensatory mechanisms in response to decreased blood volume and tissue perfusion. When there is significant fluid loss, such as from hemorrhage or dehydration, the body attempts to maintain adequate blood flow to vital organs by increasing heart rate. This compensatory tachycardia is an early sign that indicates the cardiovascular system is under stress due to reduced circulating volume.

In contrast to this, an increased blood pressure is generally not expected in hypovolemic shock; typically, blood pressure decreases as the volume of blood available for circulation diminishes. A decreased respiratory rate would not align with the body's compensatory responses either, as the demand for oxygen increases in a shock state, often resulting in a rapid or increased respiratory rate. Lastly, warm, dry skin is not characteristic of hypovolemic shock; instead, the skin may appear cool and clammy due to vasoconstriction and reduced perfusion leading to a pale and wet appearance.

Therefore, rapid heart rate serves as a vital sign that indicates the onset of hypovolemic shock and necessitates immediate assessment and intervention.