PAEA Surgery End Of Rotation (EOR) Practice Exam

What is the primary difference between hypovolemia and dehydration?

1. Hypovolemia is sodium loss while dehydration is water loss

2. Hypovolemia involves loss of both sodium and water; dehydration involves water loss

3. Hypovolemia only occurs during surgery

4. Dehydration can be fixed by increasing sodium intake

The correct answer is: Hypovolemia involves loss of both sodium and water; dehydration involves water loss

The distinction between hypovolemia and dehydration is primarily based on the types and proportions of fluids that are lost from the body. Hypovolemia refers to a decrease in the volume of blood plasma, which involves the loss of both sodium and water. This condition can occur due to various reasons, such as hemorrhage, severe burns, or excessive fluid loss from vomiting or diarrhea. Loss of sodium alongside water can lead to further complications, impacting the body's ability to maintain blood pressure and perfusion. Dehydration, on the other hand, specifically refers to a deficit in body water, which can occur without significant loss of sodium. It typically results from insufficient water intake, excessive water loss, or both, and does not necessarily imply a change in sodium levels. Therefore, dehydration results in relative hypernatremia if water loss exceeds sodium loss. Understanding these differences is crucial for managing fluid and electrolyte balance in clinical settings, particularly in patients who are experiencing severe fluid losses. Recognizing that hypovolemia involves both sodium and water loss emphasizes the need to address both components in treatment strategies, whereas dehydration primarily necessitates rehydration efforts, focusing on restoring water balance.