fluids/electolytes

prolonged vomiting and diarrhea----does this cause dehydration or hypovolemia?

I believe dehydration and hypovolemia are basically the same thing. Can someone correct me if I'm wrong?

In general terms, there are different causes of hypovolemia. Dehydration is one. So to answer the OP: protracted N/V/D will lead to hypovolemia, specifically dehydration. Contrast this to a trauma patient who has had significant blood loss: he/she would be hypovolemic secondary to blood loss.

Protracted N/V would clinically cause dehydration. Since the bodies conpensatory mechanism would prevent hypovolemia as long as possible by pulling fluids from the interstitial and intracellular spaces to prevent hypovolemia(low vascular volume) and decreased blood pressure ,etc. Remember the body is going to protect its vital organs at any cost first and will do that by attempting to sustain blood flow/pressure adequate to maintain function.

A good way to remember is as blood volume drops, the sodium level in the blood goes up and where salt goes water follows. A higher sodium level in the blood is going to pull fluids from tissue hence the compensatory mechanism trying to keep volume up in the vascular system.

OK,, technically, it would cause hypovolemia FIRST, but it wouldnt be noticed first, in a clinical setting you would see the effects as dehydration first. Take your pick.

prolonged vomiting and diarrhea----does this cause dehydration or hypovolemia?

Also causes an electrolyte (especially potassium) imbalance.