An 80 year old man presents to your ED with shortness of breath for the last 12 hours. On examination he has significant intercostal recession and tachypnoea with oxygen saturations of 88% on room air.

Vital signs:

BP 160/70

HR  110/min

RR  30/min

His ABG on 6 litres oxygen: pH  7.172

pCO2  83.3  mmHg                            pO2   64 mmHg

HCO3  29.3  mmol/l                           BE  -2.2

O2 sats  86.2 %

Hb   159  g/l

Na  133  mmol/l        K  4.3  mmol/l                Cl  95  mmol/l

Glu  13.1                 Lac  0.9  mmol/l              Creat    50  umol/l

Describe and interpret his blood gas?

List causes of his illness?

Describe key treatment interventions?