[rustyblueyez]

I think you're right superdoc1, there is a better explanation.
The most common cause of metabolic alkalosis is dehydration, suppose this patient is severely dehydrated: high pH, bicarb derangement, this might lead to loss of conciousness and subsequent ventilatory failure explaining the rising PaCO2.
You would expect to see this lower the pH but it may be a new onset i which case time would tell.