You are called to the Emergency Department to review a 45 year old man with respiratory distress. His past medical history is of HIV, with prior Pneumocystis jiroveci infections currently treated with Dapsone.
Mucous membranes appear cyanotic
Respiratory rate 35/min
HR 125/min, BP 90/50 mmHg
SpO2 82% on oxygen at 8L/min via Hudson mask
The initial arterial blood gases were as follows:
PCO2 28 mmHg
PO2 85 mmHg
Please comment on the Arterial Blood Gas results in relation to the clinical presentation.
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.