What should a nurse do first upon discovering a client having difficulty breathing after a packed red blood cell transfusion?

When a client presents with difficulty breathing after a packed red blood cell transfusion, the immediate priority is to stop the transfusion. This action is crucial because difficulty breathing may indicate a transfusion reaction, which can lead to serious complications if not addressed promptly. Stopping the transfusion halts the introduction of any potentially harmful substances into the bloodstream and allows the healthcare team to assess and manage the situation safely.

Once the transfusion is stopped, it is essential to initiate interventions that can stabilize the client's condition, such as assessing vital signs and applying oxygen if needed. However, prioritizing the cessation of the transfusion is foundational in preventing further harm and ensuring that appropriate treatment can be provided based on the patient's evolving clinical status.