Which of the following symptoms is commonly associated with decompensated shock?

Decompensated shock is a critical condition where the body is unable to maintain adequate circulation and blood flow, leading to an inability to meet the metabolic needs of organs and tissues. In this state, the body's compensatory mechanisms fail, causing severe physiological changes. Marking tachycardia, or significantly increased heart rate, is a direct response to the decreased cardiac output and reduced blood flow. The heart attempts to compensate for the low blood volume and oxygen delivery by beating faster.

In this situation, the heart's increased rate is crucial for maintaining blood pressure and perfusion to vital organs. The presence of tachycardia is a significant indicator of shock status and reflects the body's struggle to adapt to the critical condition. Therefore, this symptom is prominently associated with decompensated shock, emphasizing the urgency of medical intervention.

The other choices, such as a high-energy level, increased appetite, and stable vital signs, typically do not align with the physiological manifestations of decompensated shock. Instead, they are indicative of a state of well-being or stability, which contradicts the essence of shock where the body is in distress.