58-year-old lady with history of obstructive sleep apnoea presented with Syncope. Her venous blood gases showed the following:

PH = 7.391

pCO2 = 57 mmHg

HCO3 = 34 mmol/L

Na = 139 mmol/L

K = 2.4 mmol/L

Cl = 90 mmol/L

Hb = 134 g/L

Glucose = 12.1 mmol/L

Lactate = 2.6 mmol/L

Creatinine = 65 umol/L

explain these results