Final answer:
The nurse should notify the healthcare provider immediately due to the client's symptoms of flushing, dyspnea, and the presence of crackles in the lung bases.
Step-by-step explanation:
In this case, the nurse should notify the healthcare provider immediately. The client's symptoms of flushing, dyspnea, and the presence of crackles in the lung bases are suggestive of a possible transfusion reaction. Transfusion reactions can occur when there is an incompatibility between the donor's blood and the recipient's blood. This can lead to symptoms such as fever, chills, hives, shortness of breath, and in severe cases, low blood pressure and organ failure.