How is the fluid removal from a patient calculated during hemodialysis?

The calculation of fluid removal during hemodialysis is primarily based on the patient's weight before and after the treatment. This assessment is crucial for determining how much excess fluid has been removed, as the goal of hemodialysis is to eliminate the fluid that has accumulated in the body due to the kidneys' inability to excrete it adequately.

To understand why subtracting the estimated dry weight from the predialysis weight and adding any extra fluid received during treatment is the correct approach, one must recognize that the dry weight indicates the desired weight of the patient without excess fluid. By taking the difference between the predialysis weight and the estimated dry weight, you can calculate the total excess fluid that needs to be removed during the session. Additionally, if there are any fluids given during the treatment (like medications or saline), those must be accounted for, as they will influence the net fluid removal.

This method ensures an accurate assessment of the patient's fluid balance and helps prevent complications associated with fluid overload or excessive removal, such as hypotension or cramping. Other options may not fully account for the patient's condition or the complexities of fluid management during hemodialysis.