A 24 year old woman known to be suffering from panic disorder presents to the hospital with tingling and numbness in her fingers. ABG: pH 7.52, PCO2 2.2kPa, PO2 11kPa, Bicarb 20. What is the most likely condition?

The key is B. Acute respiratory alkalosis. [In panic attack there occurs hyperventilation which causes washout of CO2 and leads to acute respiratory alkalosis resulting in raised pH >7.45 (here 7.52), low PCO2 (here 2.2 kPa) with compensatory decrease in HCO3 (here 20meq/l)].