Supporters of Ledesma cried "Halelujah" and formed a prayer circle after the sentence was delivered at London's Southwark Crown Court yesterday.
Lera Ledesma, 49, was found responsible for the death of heart-bypass patient Ali Husseyin, 76, after she gave him a pint of type AB blood instead of type O.
She had written the name of the wrong patient on the back of her hand before performing the blood transfusion.
She also failed to realise that the blood-dispensing machine printed a receipt confirming she has the wrong patient.
Mr Huseyin died at the London Heart Hospital in May 2014. Ledesma was found guilty of manslaughter by gross negligence in December.
Judge Nicholas Loraine-Smith handed Ledesma an 18-month suspended sentence.
He said: "Mr Huseyin was a considerate man whose death has devastated his whole family...it is a mystery to me as to how you came to behave in this way. Your criminal negligence caused his death.
"I have received references and letters from an enormous number of people. Fellow nurses, doctors and consultants all paint the same picture of a dedicated nurse. This period of negligence was as out of character as can be."