Salicylate (aspirin) overdose

Mechanisms: respiratory alkalosis (early, central) → metabolic acidosis (later, uncoupling of oxidative phosphorylation). Mixed acid–base picture is classic. Features: tinnitus, hyperventilation, vomiting, fever, sweating, agitation, confusion, hypoglycaemia (esp. children), pulmonary oedema (non-cardiogenic), seizures, coma. ABCDE; bloods: salicylate level (repeat 2-hourly until peak), VBG, U&E, glucose, lactate, paracetamol, INR, FBC, ECG (look for QT prolongation and signs of hypokalaemia).