What is possible thing will occurs when we give B+ PRBCs for A+ female patient ?

[emadlabs]

38 years old , female for C/S request for 4 units blood 

By wrong way from technition give 4 units B+ Packed RBCs unfortunately the patient was A+ in the fact but the technetion was made x matching with the other sample which was belonged other patient 

The doctors told that the patient has taken approximately 2 units B+ blood ! 

What may occurs with patient and what the suitable steps for blood bank to save the patient