Blood tests:
For the blood tests you want to be doing your standard infection sweep, always good to check your ESR (Plasma Volume in NHS Highland).
If your patient is systemically unwell a septic screen should be given with your blood cultures and lactate etc.
The key thing undertaken in secondary care are your swabs / bone biopsies as these may help to locate a source of the infection and will guide antimicrobial therapy.
The bone biopsies are something Ortho and Max Fax should be doing however taking a swab of wounds and getting more detailed information on the causative pathogen(s) is something that can be done in primary care and is invaluable information as it may locate the source of infection.