A 53 year old with a history of psychiatric issues presents with altered mental state. She is tachypnoeic and looks unwell.

Her blood tests:

pH   7.25  (7.36-7.44)

pCO2  35.1  (35-45 mmHg)

BE  -11.1

Hb  87

Na  142  (137-145   mmol/l)

K  2.5  (3.5-5 mmol/l)

Cl  118  (99-111 mmol/l)

Describe and interpret

What drug typically accounts for this picture?

What complication is likely and what bedside and lab test would be helpful?

What ECG changes would you expect?