A middle aged man with history of hypertension and GORD, presented to the emergency department with epigastric pain. He looked slightly dehydrated.
Venous blood gas showed the following:

PH = 7.49
PCO2 = 50 mmHg
PO2 = 42 mmHg

HCO3 = 41 mmol/L
Na = 144 mmol/L
Cl = 94 mmol/L
K = 3.5 mmol/L
Calcium (Ionised) = 1.63 mmol/L (Normal range= 1.12 – 1.32).
Glucose = 5.6 mmol/L
Lactate = 2.1 mmol/L
Creatinine = 168 umol/L

Questions:
– Interpret these blood gases and what are the causes of these changes?
– What is the Differential diagnosis of hypercalcemia and what additional tests are required?
– What is your management approach for hypercalcemia?