An 11-year-old girl with dystonic cerebral palsy was brought to the emergency department. She was estimated to be at level V on the Gross Motor Function Classification System (GMFCS) and had limited verbal communication. Other coexisting medical problems were gastro-oesophageal reflux and epilepsy. She was on regular carbamazepine, domperidone and ranitidine.

Her parents gave a history of ‘agitation’ and intermittent fever for 1 week. On assessment, oxygen saturations …