You are put on standby for a 48 year old male with a collapse and upper GI Bleeding. Whilst you ready the resus room he arrives.

He is vomiting bright red blood and smells of melaena (he will produce quite a bit for examination later, but at the moment it is the smell that gives it away). He is confused and does not give much in the way of history, one of your nurses recognises him as a regular attender with a significant alcoholic history.

Clinical examination reveals the following:-
Airway - intact
Breathing - Resp rate of 20
Circulation - Pulse 140, BP 100/60, poor peripheral perfusion.
Disabilirty - GCS 14 (confusion)
E - ascites, palmar erythema and numerous spider naevae

He has a prescription in his pocket which suggests that he has recently been started on Spirinolactone and Frusemide by his GP.

You give him oxygen, place 2 large bore IVI and start some colloid. You also take bloods for FBC, UE, Gluc, Clotting, Cross match, LFTs and amylase.

In addition you take some venous blood into a gas syringe and put it through your gas machine in the resus room.

Would you like to see the venous blood gases?