Answer:
To be sure about the cause of the pain.
Step-by-step explanation:
The nurse must ensures the presence of bacteria or microbes before the antibiotics are given because the antibiotic is used for the killing of these microbes such as bacteria. endocarditis happens when the bacteria or fungi enters to the heart through blood streams and cause problems there so for removing this infection we must use antibiotic that kills this microorganisms so the nurse has to make sure that the symptoms is due to microbes or not before the use of antibiotic to avoid any consequences.