What happens to fluid when hypotonic fluids are administered?

When hypotonic fluids are administered, they have a lower osmolarity compared to the fluid inside the body’s cells. This difference in osmotic pressure causes water to move from the extracellular space (where the hypotonic fluid is) into the intracellular space (inside the cells) to balance the osmolarity between the two compartments. As a result, the fluid shifts into the cells, causing them to swell.

This process is especially relevant in clinical settings where managing fluid balance is crucial, such as in cases of hypernatremia or dehydration. Administering hypotonic solutions can help rehydrate cells, making it an important strategy in certain fluid replacement therapies. Understanding this mechanism is vital for healthcare professionals to effectively manage fluids in critically ill patients.