Viva 6

A 72 year old diabetic male is admitted to the Intensive Care Unit with a history of loin pain. He is febrile, tachycardic, hypotensive and tachypnoeic but stabilizes after fluid resuscitation and vasopressor infusion.
 
Describe your approach  to the investigation and management of the underlying condition.

Disclaimer: the viva stem above may be an original CICM stem, acquired from their publicly available past papers. Or, perhaps it is a slightly altered version of the original CICM stem. Or, it is a completely original viva stem, concocted by the monstrously amoral author of Deranged Physiology for nothing more than his own personal amusement. In either case, because the college do not make the main viva text or marking criteria available, almost everything here has been confabulated. It might sound like a plausible viva and it could be used for the purpose of practice, but all should be aware that it does not represent the "true" canonical CICM viva station.