Final answer:
In the case of a client with infective endocarditis, obtaining blood cultures should be implemented first.
Step-by-step explanation:
The HCP's order that should be implemented first in the case of a client with infective endocarditis is b. Obtain blood cultures times 2. Blood cultures are crucial in diagnosing infective endocarditis by identifying the causative bacteria and determining their susceptibility to antibiotics. This information is essential for selecting the appropriate antibiotic therapy. Administering the IV antibiotic (a) and scheduling an echocardiogram (c) are important, but obtaining blood cultures is the first step in the management of infective endocarditis.