Oncology Certified Nurse (OCN) Nursing Practice Test

How is fluid in the interstitial space defined?

1. Dehydration

2. Edema

3. Lymphedema

4. Hypervolemia

The correct answer is: Edema

Fluid in the interstitial space is defined as edema. Edema refers to the accumulation of fluid within the interstitial spaces and can occur due to various reasons, such as increased capillary permeability, decreased oncotic pressure, or obstruction of lymphatic drainage. The presence of excess fluid in these spaces leads to swelling and can affect various bodily functions and processes. Dehydration, while related to fluid balance, specifically refers to a state in which there is a deficit of water in the body, leading to a concentration of solutes. Lymphedema is a specific type of edema caused by a blockage in the lymphatic system, resulting in localized fluid retention. Hypervolemia refers to an increase in the volume of blood and not specifically to the interstitial spaces, making it unrelated to the definition of fluid in the interstitial space. Thus, edema is the most accurate term to describe fluid accumulation outside the blood vessels, within the interstitial compartments.