A casualty in decompensated shock from hypovolemia shows which of these signs?

In cases of decompensated shock due to hypovolemia, the body is unable to maintain adequate perfusion of tissues despite compensatory mechanisms. This often leads to hypotension, or falling blood pressure. The loss of blood volume reduces the heart's ability to pump adequately, which can manifest as a significant drop in blood pressure.

The other signs of shock may include an increased heart rate as the body attempts to compensate for reduced perfusion, but in decompensated shock, the heart rate may eventually also decrease due to profound weakness. A stable blood pressure usually indicates that the compensatory mechanisms are working, which is not the case in decompensated shock. Finally, a normal mental status typically suggests that sufficient blood flow is still reaching the brain, which would not be expected in a state of decompensated shock characterized by hypoperfusion. Thus, falling blood pressure is the hallmark sign indicating that the shock state is worsening.