What immediate action should be taken if a patient begins to experience hypotension during dialysis?

When a patient experiences hypotension during dialysis, the immediate action of administering fluids is crucial. Hypotension can occur due to various factors such as fluid removal, ultrafiltration rates, or changes in the patient's condition. Administering fluids can help to restore blood volume and stabilize blood pressure, which is essential for the patient’s safety and well-being.

Replenishing fluids can mitigate symptoms associated with low blood pressure, such as dizziness, weakness, and confusion, providing symptomatic relief. It's important to note that while stopping the treatment or increasing the treatment rate may seem like options, they may not directly address the underlying issue of volume depletion. Calling for assistance is also a necessary step but may not provide immediate relief to the patient's condition at that moment.

Therefore, administering fluids effectively addresses the problem of hypotension by enhancing hemodynamic stability and is the most appropriate immediate response in this scenario.