While receiving a blood transfusion, a client develops acute dyspnea, generalized urticaria, a heart rate of 128, and a blood pressure of 70/38. what type of reaction does the nurse conclude that the client probably is experiencing?

The client probably experiencing anaphylaxis reaction. 

Anaphylaxis is a severe allergic reaction with rapid onset and may cause death. In anaphylaxis, systemic vasodilatation that results from the reaction will cause shock.
The symptoms could be decreased blood pressure(hypotension), increased heart rate, dyspnea and loss of consciousness.
The transfusion should be stopped and an epinephrine shot should be given as fast as possible to this client.

The answer is constant.