What specific sign should a client report immediately after the nurse starts a transfusion of packed red blood cells?

The correct response to report immediately after the initiation of a transfusion of packed red blood cells is shortness of breath. This symptom can indicate a potentially serious and immediate reaction, such as a transfusion-related acute lung injury (TRALI) or an allergic reaction affecting the respiratory system.

Shortness of breath during a blood transfusion is critical because it may suggest that the body is rejecting the blood product or that there is an issue with fluid overload, leading to pulmonary issues. Symptoms like this could escalate rapidly and require prompt medical intervention.

While headache, rash, and fever can also occur during a transfusion and warrant attention, they do not typically signal an immediate life-threatening response. For instance, a headache or fever may indicate a more gradual complication such as a febrile non-hemolytic reaction, and a rash could point to an allergic reaction. However, none of these symptoms pose the same immediate risk to respiratory function as shortness of breath does, making this the most critical sign to report without delay.