護理師評估一位可能有低血容性休克的病人，哪項發現是最早期的臨床症狀？
A nurse is assessing a client for signs of potential hypovolemic shock. Which finding is the earliest clinical manifestation?
- ADecreased blood pressure血壓降低
- BTachycardia✓ 正解心搏過速
- CAltered level of consciousness意識狀態改變
- DOliguria少尿
在低血容性休克（Hypovolemic Shock）的發展過程中，身體會優先啟動交感神經代償機制。為了維持重要器官的灌流量（Cardiac Output = Heart Rate × Stroke Volume），心跳會首先代償性加速（Tachycardia）。血壓下降與尿量減少則是代償失調後的晚期指標，代表身體已無法維持足夠的循環血量，病情已進入危險期。
In the course of hypovolemic shock, the body preferentially activates sympathetic compensatory mechanisms. To maintain perfusion of vital organs (Cardiac Output = Heart Rate × Stroke Volume), the heart rate first increases compensatorily (tachycardia). A fall in blood pressure and a decrease in urine output are late indicators of decompensation, indicating that the body can no longer maintain adequate circulating volume and that the patient has entered a critical phase.